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Linhares BDA, Nunes GT, Bianchini A, Bertolini L, Vilela F, Efe MA, Rodrigues FL, Lanco S, Zebral YD, Costa PG, Bugoni L. Resource partitioning influences levels of toxic trace elements in sympatric tropical seabirds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175102. [PMID: 39074745 DOI: 10.1016/j.scitotenv.2024.175102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 07/25/2024] [Accepted: 07/26/2024] [Indexed: 07/31/2024]
Abstract
Morphologically similar species that occupy resource-limited environments tend to differ in their ecological traits in order to coexist, which may result in differential exposure to environmental threats. For instance, partitioning of feeding resources may influence contaminant exposure and bioaccumulation in marine predators through different diets or foraging habitats. Here, we sampled three tropical seabird species breeding in sympatry in the southwestern Atlantic Ocean for blood and feather trace element concentrations (As, Hg, Cd, Pb), and assessed their foraging ecology with bio-logging (GPS tracks and time-depth recorders), analysis of regurgitated prey, and carbon and nitrogen stable isotope mixing models. Red-billed tropicbirds (Phaethon aethereus), brown (Sula leucogaster) and masked (S. dactylatra) boobies differed in their preferred foraging locations, the range of foraging trips, diving parameters and diets. In addition, interspecific differences were detected in blood or feathers for all trace elements analyzed, suggesting influence of the differences observed in diet and space use. Red-billed tropicbirds had the largest foraging range over the continental shelf and over the slope, suggesting lower exposure to continental sources of metals. Brown and masked boobies had higher Hg concentrations than tropicbirds, higher δ15N values (a proxy for trophic level), and δ15N correlated with Hg levels, suggesting biomagnification of Hg along the food chain. Nonetheless, red-billed tropicbirds showed comparable levels of As and Cd in blood or feathers, and higher levels of Pb in both tissues in comparison to boobies, which may suggest overall exposure of seabirds in the region, through their diets and foraging areas. Resource partitioning is critical for allowing coexistence of different seabird species in shared breeding sites where they act as central-place foragers. Nonetheless, in scenarios of environmental pollution, these species-specific strategies lead to differential bioaccumulation, and thus distinct effects of pollution on populations are expected.
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Affiliation(s)
- Bruno de Andrade Linhares
- Programa de Pós-Graduação em Oceanografia Biológica, Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, 96203-900 Rio Grande, RS, Brazil; Laboratório de Aves Aquáticas e Tartarugas Marinhas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande - FURG, 96203-900 Rio Grande, RS, Brazil.
| | - Guilherme Tavares Nunes
- Centro de Estudos Costeiros, Limnológicos e Marinhos, Universidade Federal do Rio Grande do Sul - UFRGS, 95625-000 Imbé, RS, Brazil
| | - Adalto Bianchini
- Programa de Pós-Graduação em Oceanografia Biológica, Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, 96203-900 Rio Grande, RS, Brazil; Laboratório de Determinações 2, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande - FURG, 96203-900 Rio Grande, RS, Brazil
| | - Luísa Bertolini
- Centro de Estudos Costeiros, Limnológicos e Marinhos, Universidade Federal do Rio Grande do Sul - UFRGS, 95625-000 Imbé, RS, Brazil
| | - Fiorella Vilela
- Centro de Estudos Costeiros, Limnológicos e Marinhos, Universidade Federal do Rio Grande do Sul - UFRGS, 95625-000 Imbé, RS, Brazil; Programa de Pós Graduação em Biologia Animal, Universidade Federal do Rio Grande do Sul - UFRGS, 90035-003 Porto Alegre, RS, Brazil
| | - Márcio Amorim Efe
- Laboratório de Bioecologia e Conservação de Aves Neotropicais, Universidade Federal de Alagoas - UFAL, 57072-900 Maceió, AL, Brazil
| | - Fábio Lameiro Rodrigues
- Centro de Estudos Costeiros, Limnológicos e Marinhos, Universidade Federal do Rio Grande do Sul - UFRGS, 95625-000 Imbé, RS, Brazil; Programa de Pós Graduação em Biologia Animal, Universidade Federal do Rio Grande do Sul - UFRGS, 90035-003 Porto Alegre, RS, Brazil
| | - Sophie Lanco
- Institut de Recherche pour le Développement, MARBEC (Univ. Montpellier, Ifremer, CNRS, IRD), Centre de Recherche Halieutique Méditerranéenne et Tropicale, 34203 Sète Cedex, France
| | - Yuri Dornelles Zebral
- Laboratório de Determinações 2, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande - FURG, 96203-900 Rio Grande, RS, Brazil
| | - Patrícia Gomes Costa
- Laboratório de Determinações 2, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande - FURG, 96203-900 Rio Grande, RS, Brazil
| | - Leandro Bugoni
- Programa de Pós-Graduação em Oceanografia Biológica, Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, 96203-900 Rio Grande, RS, Brazil; Laboratório de Aves Aquáticas e Tartarugas Marinhas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande - FURG, 96203-900 Rio Grande, RS, Brazil
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Martínez Rodríguez A, Kratina P, Jones JI. Microplastic pollution and nutrient enrichment shift the diet of freshwater macroinvertebrates. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 359:124540. [PMID: 39004208 DOI: 10.1016/j.envpol.2024.124540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/25/2024] [Accepted: 07/11/2024] [Indexed: 07/16/2024]
Abstract
Microplastic pollution poses a global threat to freshwater ecosystems, with laboratory experiments indicating potential toxic impacts through chemical toxicity, physical abrasion, and false satiation. Bioplastics have emerged as a potential greener alternative to traditional oil-based plastics. Yet, their environmental effects remain unclear, particularly at scales relevant to the natural environment. Additionally, the interactive impacts of microplastics with other environmental stressors, such as nutrient enrichment, are poorly understood and rarely studied. Under natural conditions organisms might be able to mitigate the toxic effects of microplastics by shifting their diet, but this ability may be compromised by other stressors. This study combines an outdoor mesocosm experiment and stable isotope analysis to determine changes in the trophic niches of three freshwater invertebrate species exposed to conventional (HDPE) and bio-based biodegradable (PLA) microplastics at two concentrations, both independently and combined with nutrient enrichment. Exposure to microplastics altered the isotopic niches of two of the invertebrate species, with nutrient enrichment mediating this effect. Moreover, the effects of microplastics were consistent regardless of their type or concentration. Under enriched conditions, two of the species exposed to microplastics shifted to a specialised diet compared with controls, whereas little difference was observed between the isotopic niches of those exposed to microplastic and controls under ambient nutrient conditions. Additionally, PLA was estimated to support 24 % of the diet of one species, highlighting the potential assimilation of bioplastics by biota and possible implications. Overall, these findings suggest that the toxic effects of microplastics suggested from laboratory studies might not manifest under real-world conditions. However, this study does demonstrate that subtle sublethal effects occur even at environmentally realistic microplastic concentrations. The crucial role of nutrient enrichment in mediating microplastic effects underscores the importance of considering microplastic pollution in the context of other environmental stressors.
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Affiliation(s)
- Ana Martínez Rodríguez
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
| | - Pavel Kratina
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - J Iwan Jones
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
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Lu K, Chen Z, He X, Wu H, He F. Slow recovery in trophic structure of restored wetlands in Northeast China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 952:175803. [PMID: 39197779 DOI: 10.1016/j.scitotenv.2024.175803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 08/12/2024] [Accepted: 08/24/2024] [Indexed: 09/01/2024]
Abstract
Restoration measures have been widely implemented in wetland ecosystems globally to bend the curve of biodiversity loss and restore associated ecological functions. However, assessments of the effectiveness of wetland restoration have predominantly focused on the recovery of taxonomic composition, while few studies have assessed the effectiveness of these efforts from a food web perspective. Here, we incorporated stable isotope approach to investigate trophic structure in natural and restored wetlands in Northeast China. The investigated consumers, including zooplankton, macroinvertebrates, and fish, exhibited lower δ15N and higher δ13C values in restored wetlands than in natural wetlands. Natural wetlands exhibited higher trophic positions and a wider range of trophic levels compared to restored wetlands. Primary consumers in natural wetlands relied more on particulate organic matter (POM, 42.9 % ± 24.1 %), while those in restored wetlands were more dependent on substrate organic matter (SOM, 42.3 % ± 23.9 %). Compared to natural wetlands, isotopic richness was significantly lower in restored wetlands, with smaller isotopic variation (SEAs) in basal resources, aquatic invertebrates, and fish. Our findings reveal that the recovery of trophic structures in restored wetlands lags behind that of taxonomic composition. Future restoration efforts should prioritize enhancing habitat heterogeneity and resource availability to support a diverse range of trophic levels. Monitoring trophic dynamics is essential for assessing the progress of wetland restoration and should be integrated into monitoring schemes.
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Affiliation(s)
- Kangle Lu
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, Jilin 130102, China; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, Jilin 130102, China
| | - Zhanyan Chen
- Moutai Institute of Science and Technology, Zunyi, Guizhou 564501, China
| | - Xinhua He
- School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia; Department of Land, Air and Water Resources, University of California at Davis, Davis, CA 95616, USA
| | - Haitao Wu
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, Jilin 130102, China; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, Jilin 130102, China.
| | - Fengzhi He
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, Jilin 130102, China; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, Jilin 130102, China
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Liu Z, Guo Y, Qin C, Mu X, Zhang J. High-Throughput Sequencing Analysis Revealed a Preference for Animal-Based Food in Purple Sea Urchins. BIOLOGY 2024; 13:623. [PMID: 39194561 DOI: 10.3390/biology13080623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 08/09/2024] [Accepted: 08/09/2024] [Indexed: 08/29/2024]
Abstract
Sea urchins play an important role in marine ecosystems. Owing to limitations in previous research methods, there has been insufficient understanding of the food sources and ecological functional value of purple sea urchins, leading to considerable controversy regarding their functional positioning. We focused on Daya Bay as the research area, utilizing stable isotope technology and high-throughput sequencing of 16S rDNA and 18S rDNA to analyze sea urchins and their potential food sources in stone and algae areas. The results showed that the δ13C range of purple sea urchins in the stone area is -11.42~-8.17‱, and the δ15N range is 9.15~10.31‱. However, in the algal area, the δ13C range is -13.97~-12.44‱, and the δ15N range is 8.75~10.14‱. There was a significant difference in δ13C between the two areas (p < 0.05), but there was no significant difference in δ15N (p > 0.05). The main food source for purple sea urchins in both areas is sediment. The sequencing results of 18S rDNA revealed that, in the algal area, the highest proportion in the sea urchin gut was Molluska (57.37%). In the stone area, the highest proportion was Arthropoda (76.71%). The sequencing results of 16S rDNA revealed that, in the algal area, Bacteroidetes was the dominant group in the sea urchin gut (28.87%), whereas, in the stone area, Proteobacteria was the dominant group (37.83%). Diversity detection revealed a significant difference in the number of gut microbes and eukaryotes between the stone and algal areas (p < 0.05). The results revealed that the main food source of purple sea urchins in both areas is sediment, but the organic nutritional value is greater in the algal area, and the richness of microbiota and eukaryotes in the gut of purple sea urchins in the stone area is greater. These results indicated that purple sea urchins are likely omnivores and that the area where they occur impacts their growth and development. The results of this study provide a theoretical basis for the restoration of wild purple sea urchin resources and the selection of areas for restocking and release.
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Affiliation(s)
- Zerui Liu
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
- Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572018, China
- College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Yu Guo
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
- Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572018, China
- Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
| | - Chuanxin Qin
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
- Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572018, China
| | - Xiaohui Mu
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
- Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572018, China
| | - Jia Zhang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China
- Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572018, China
- College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
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MacRae PSD, Russell M, Cowan JH, Fry B, Moyo S, Polito MJ. Consistencies in the dietary and isotopic niche of spotted seatrout, Cynoscion nebulosus, across a salinity gradient within a coastal Louisiana estuary. JOURNAL OF FISH BIOLOGY 2024; 105:459-471. [PMID: 38964749 DOI: 10.1111/jfb.15810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 05/02/2024] [Accepted: 05/10/2024] [Indexed: 07/06/2024]
Abstract
Estuaries are essential habitats for recreational and commercial fish that are shaped by both natural and anthropogenic processes. In Louisiana a combination of climate change and planned coastal restoration actions is predicted to increase freshwater introduction to coastal estuaries. As such there is a need to quantify the relationships between estuarine fish ecology and salinity to aid in predicting how species will respond to shifts in salinity. We investigated the relative abundance and dietary niches of adult (24.5 ± 5.4 cm standard length) spotted seatrout Cynoscion nebulosus across varying salinity regimes (oligohaline, mesohaline, and polyhaline) within Barataria Bay, Louisiana, using a combination of net sampling and gut content and stable isotopes analysis. We found that the relative abundance of C. nebulosus was lowest at the oligohaline site, translating to approximately five fewer fish captured for every single psu decrease in a site's average annual salinity. In contrast, we found that diets and, to a lesser extent, isotopic niches had a high degree of overlap across sites with differing salinity regimes. Fish and penaeid shrimp were the most common and important prey taxa recovered from guts at all sites. The small isotopic differences found among sites were likely due to spatial variation in hydrogeochemical baselines, and the observed isotopic overlap provides support for the idea that C. nebulosus move between adjacent salinity regimes and forage throughout Barataria Bay. Our results contribute to a greater understanding of the salinity preference and trophic ecology of C. nebulosus that can aid in predicting their responses to future salinity and habitat changes within Barataria Bay associated with predicted climate change and planned coastal restoration actions.
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Affiliation(s)
- Pamela S D MacRae
- College of Arts and Sciences, University of Maine at Augusta, Augusta, Maine, USA
| | - Micah Russell
- School of Environment and Sustainability, Western Colorado University, Gunnison, Colorado, USA
| | - James H Cowan
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Brian Fry
- Australian Rivers Institute, Griffith University, Brisbane, Queensland, Australia
| | - Sydney Moyo
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Michael J Polito
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
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Lovell MS, Polito MJ, Schuster JA, Shallow EE, Janosik AM, Falterman BJ, Dance MA. Seasonal variability in the feeding ecology of an oceanic predator. Sci Rep 2024; 14:17353. [PMID: 39075103 PMCID: PMC11286940 DOI: 10.1038/s41598-024-63557-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 05/30/2024] [Indexed: 07/31/2024] Open
Abstract
Complementary approaches (stomach contents, DNA barcoding, and stable isotopes) were used to examine seasonal shifts in the feeding ecology of an oceanic predator, yellowfin tuna (Thunnus albacares, n = 577), in the northern Gulf of Mexico. DNA barcoding greatly enhanced dietary resolution and seasonally distinct prey assemblages were observed for both sub-adults and adults. In general, diet was characterized by ommastrephid squids and exocoetids in spring, juvenile fishes (i.e., carangids and scombrids) in summer, migratory coastal fishes during fall, and an increased consumption of planktonic prey (e.g., amphipods) in winter. Seasonal variability in bulk stable isotope values (δ13C, δ15N, and δ34S) was also observed, with low δ15N values and high δ34S values during late summer/early fall and high δ15N values (low δ34S) during late winter/early spring. Bayesian stable isotope mixing models corroborated seasonal diet shifts, highlighting the importance of oceanic nekton in spring/summer, coastal nekton during fall, and oceanic plankton during winter. Seasonal shifts in diet appeared to be influenced by prey reproductive cycles, habitat associations, and environmental conditions. Findings highlight the complex food web dynamics supporting an opportunistic oceanic predator and the importance of seasonal cycles in prey availability to predator resource utilization in open-ocean ecosystems.
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Affiliation(s)
- Mitchell S Lovell
- Department of Oceanography & Coastal Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA.
| | - Michael J Polito
- Department of Oceanography & Coastal Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Josef A Schuster
- Department of Oceanography & Coastal Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Emily E Shallow
- Department of Oceanography & Coastal Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Alexis M Janosik
- Department of Biology, University of West Florida, Pensacola, FL, 32514, USA
| | | | - Michael A Dance
- Department of Oceanography & Coastal Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
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Gerstle V, Bollinger E, Manfrin A, Pietz S, Kolbenschlag S, Feckler A, Entling MH, Brühl CA. Trophic effects of Bti-based mosquito control on two top predators in floodplain pond mesocosms. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:45485-45494. [PMID: 38967849 PMCID: PMC11269390 DOI: 10.1007/s11356-024-34124-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 06/21/2024] [Indexed: 07/06/2024]
Abstract
Chironomid (Diptera: Chironomidae) larvae play a key role in aquatic food webs as prey for predators like amphibian and dragonfly larvae. This trophic link may be disrupted by anthropogenic stressors such as Bacillus thuringiensis var. israelensis (Bti), a biocide widely used in mosquito control. In a companion study, we recorded a 41% reduction of non-target larval chironomids abundance in outdoor floodplain pond mesocosms (FPMs) treated with Bti. Therefore, we examined the diet of two top predators in the FPMs, larvae of the palmate newt (Salamandridae: Lissotriton helveticus) and dragonfly (Aeshnidae: predominantly Anax imperator), using bulk stable isotope analyses of carbon and nitrogen. Additionally, we determined neutral lipid fatty acids in newt larvae to assess diet-related effects on their physiological condition. We did not find any effects of Bti on the diet proportions of newt larvae and no significant effects on the fatty acid content. We observed a trend in Aeshnidae larvae from Bti-FPMs consuming a higher proportion of large prey (Aeshnidae, newt, damselfly larvae; ~42%), and similar parts of smaller prey (chironomid, mayfly, Libellulidae, and zooplankton), compared to controls. Our findings may suggest bottom-up effects of Bti on aquatic predators but should be further evaluated, for instance, by using compound-specific stable isotope analyses of fatty acids or metabarcoding approaches.
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Affiliation(s)
- Verena Gerstle
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany.
- Eußerthal Ecosystem Research Station, RPTU Kaiserslautern-Landau, Birkenthalstraße 13, D-76857, Eußerthal, Germany.
| | - Eric Bollinger
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Alessandro Manfrin
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Sebastian Pietz
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Sara Kolbenschlag
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Alexander Feckler
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
- Eußerthal Ecosystem Research Station, RPTU Kaiserslautern-Landau, Birkenthalstraße 13, D-76857, Eußerthal, Germany
| | - Martin H Entling
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Carsten A Brühl
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
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Arnoldi JF, Bortoluzzi JR, Rowland H, Harrod C, Parnell AC, Payne N, Donohue I, Jackson AL. How strongly does diet variation explain variation in isotope values of animal consumers? PLoS One 2024; 19:e0301900. [PMID: 38935686 PMCID: PMC11210776 DOI: 10.1371/journal.pone.0301900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 03/25/2024] [Indexed: 06/29/2024] Open
Abstract
Analysis of stable isotopes in consumers is used commonly to study their ecological and/or environmental niche. There is, however, considerable debate regarding how isotopic values relate to diet and how other sources of variation confound this link, which can undermine the utility. From the analysis of a simple, but general, model of isotopic incorporation in consumer organisms, we examine the relationship between isotopic variance among individuals, and diet variability within a consumer population. We show that variance in consumer isotope values is directly proportional to variation in diet (through Simpson indices), to the number of isotopically distinct food sources in the diet, and to the baseline variation within and among the isotope values of the food sources. Additionally, when considering temporal diet variation within a consumer we identify the interplay between diet turnover rates and tissue turnover rates that controls the sensitivity of stable isotopes to detect diet variation. Our work demonstrates that variation in the stable isotope values of consumers reflect variation in their diet. This relationship, however, can be confounded with other factors to the extent that they may mask the signal coming from diet. We show how simple quantitative corrections can recover a direct 1:1 correlation in some situations, and in others we can adjust our interpretation in light of the new understanding arising from our models. Our framework provides guidance for the design and analysis of empirical studies where the goal is to infer niche width from stable isotope data.
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Affiliation(s)
| | - Jenny Rose Bortoluzzi
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | | | - Chris Harrod
- Instituto de Ciencias Naturales Alexander von Humboldt, Universidad de Antofagasta, Antofagasta, Chile
- Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
- Millennium Nucleus of Austral Invasive Salmonids (INVASAL), Concepciòn, Chile
| | - Andrew C. Parnell
- Insight Centre for Data Analytics, Hamilton Institute, Maynooth University, Kildare, Ireland
| | - Nicholas Payne
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Ian Donohue
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Andrew L. Jackson
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
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Gurney KEB, Classen HL, Clark RG. Testing for effects of growth rate on isotope trophic discrimination factors and evaluating the performance of Bayesian stable isotope mixing models experimentally: A moment of truth? PLoS One 2024; 19:e0304495. [PMID: 38875228 PMCID: PMC11178173 DOI: 10.1371/journal.pone.0304495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 05/13/2024] [Indexed: 06/16/2024] Open
Abstract
Discerning assimilated diets of wild animals using stable isotopes is well established where potential dietary items in food webs are isotopically distinct. With the advent of mixing models, and Bayesian extensions of such models (Bayesian Stable Isotope Mixing Models, BSIMMs), statistical techniques available for these efforts have been rapidly increasing. The accuracy with which BSIMMs quantify diet, however, depends on several factors including uncertainty in tissue discrimination factors (TDFs; Δ) and identification of appropriate error structures. Whereas performance of BSIMMs has mostly been evaluated with simulations, here we test the efficacy of BSIMMs by raising domestic broiler chicks (Gallus gallus domesticus) on four isotopically distinct diets under controlled environmental conditions, ideal for evaluating factors that affect TDFs and testing how BSIMMs allocate individual birds to diets that vary in isotopic similarity. For both liver and feather tissues, δ13C and δ 15N values differed among dietary groups. Δ13C of liver, but not feather, was negatively related to the rate at which individuals gained body mass. For Δ15N, we identified effects of dietary group, sex, and tissue type, as well as an interaction between sex and tissue type, with females having higher liver Δ15N relative to males. For both tissues, BSIMMs allocated most chicks to correct dietary groups, especially for models using combined TDFs rather than diet-specific TDFs, and those applying a multiplicative error structure. These findings provide new information on how biological processes affect TDFs and confirm that adequately accounting for variability in consumer isotopes is necessary to optimize performance of BSIMMs. Moreover, results demonstrate experimentally that these models reliably characterize consumed diets when appropriately parameterized.
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Affiliation(s)
- Kirsty E B Gurney
- Science and Technology Branch, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
| | - Henry L Classen
- College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Robert G Clark
- Science and Technology Branch, Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
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Scharnweber K, Milano S, Hühn D. Influence of the dietary contribution of terrestrial insects to the condition factor of bleak Alburnus alburnus in a highly polluted lowland river. JOURNAL OF FISH BIOLOGY 2024. [PMID: 38840428 DOI: 10.1111/jfb.15835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 05/14/2024] [Accepted: 05/22/2024] [Indexed: 06/07/2024]
Abstract
Bleak Alburnus alburnus is a highly abundant but understudied fish species, and we know little about the trophic ecology of populations inhabiting rivers in central Europe. From an ecosystem perspective, this fish species is interesting as it is known to feed on surface insects, thereby linking the terrestrial with the aquatic habitat. In a previous study, we demonstrated that this flux is intensified, and dietary contribution of terrestrial insects is higher in fish inhabiting sections of the Spree River, Germany, that are polluted from iron oxides occurring from former lignite mining activities, and thus are characterized by lower abundances of aquatic insects. As terrestrial insects can be considered as food of lower quality (measured as long-chained polyunsaturated fatty acids, n-3 LC-PUFAs) compared to aquatic prey, it is reasonable to assume that the higher contribution of terrestrial insects is related to a lower body condition in fish. In this study, we explore the trophic ecology of riverine A. alburnus and their fitness consequences of feeding on terrestrial insects. We therefore modeled a terrestrial index from stable isotopes of hydrogen (δ2H) measured in the A. alburnus muscle tissue and compared individuals caught in locations upstream of a dam that were greatly influenced by iron oxides, with individuals caught in sections located downstream of a dam where passive remediation technologies are applied. The terrestrial index was significantly higher in A. alburnus caught in locations at high-iron concentrations, characterized by low abundances of aquatic prey, compared to A. alburnus caught in unpolluted habitats at low-iron concentrations. In contradiction to our hypothesis, the terrestrial index had no significant effect on the body condition of A. alburnus (measured as Fulton's condition factor K) in the sections downstream of the dam (i.e., at low-iron concentrations) and a significant positive, albeit weak, effect in sections upstream of the dam (i.e., at high-iron concentrations). However, the condition factor was generally lower in the high-iron section, potentially related to more direct effects of the iron oxide. We conclude that in A. alburnus, terrestrial insects can be considered as the less-favored food, unless the fish occur in environments where the aquatic food is of limited availability. Further research is needed to evaluate the direct and indirect effects, including the internal n-3 LC-PUFA synthesis as an adaption toward low-quality terrestrial prey on the fitness consequences of A. alburnus.
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Affiliation(s)
- Kristin Scharnweber
- Plant Ecology and Nature Conservation, University of Potsdam, Potsdam, Germany
- Ecological Research Station, University of Cologne, Rees, Germany
| | | | - Daniel Hühn
- Potsdam Institute of Inland Fisheries, Potsdam, Germany
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11
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Webster SC, Hinton JW, Chamberlain MJ, Murphy JJ, Beasley JC. Land cover and space use influence coyote carnivory: evidence from stable-isotope analysis. PeerJ 2024; 12:e17457. [PMID: 38854793 PMCID: PMC11160434 DOI: 10.7717/peerj.17457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 05/03/2024] [Indexed: 06/11/2024] Open
Abstract
For many species, the relationship between space use and diet composition is complex, with individuals adopting varying space use strategies such as territoriality to facilitate resource acquisition. Coyotes (Canis latrans) exhibit two disparate types of space use; defending mutually exclusive territories (residents) or moving nomadically across landscapes (transients). Resident coyotes have increased access to familiar food resources, thus improved foraging opportunities to compensate for the energetic costs of defending territories. Conversely, transients do not defend territories and are able to redirect energetic costs of territorial defense towards extensive movements in search of mates and breeding opportunities. These differences in space use attributed to different behavioral strategies likely influence foraging and ultimately diet composition, but these relationships have not been well studied. We investigated diet composition of resident and transient coyotes in the southeastern United States by pairing individual space use patterns with analysis of stable carbon (δ13C) and nitrogen (δ15N) isotope values to assess diet. During 2016-2017, we monitored 41 coyotes (26 residents, 15 transients) with GPS radio-collars along the Savannah River area in the southeastern United States. We observed a canopy effect on δ13C values and little anthropogenic food in coyote diets, suggesting 13C enrichment is likely more influenced by reduced canopy cover than consumption of human foods. We also observed other land cover effects, such as agricultural cover and road density, on δ15N values as well as reduced space used by coyotes, suggesting that cover types and localized, resident-like space use can influence the degree of carnivory in coyotes. Finally, diets and niche space did not differ between resident and transient coyotes despite differences observed in the proportional contribution of potential food sources to their diets. Although our stable isotope mixing models detected differences between the diets of resident and transient coyotes, both relied mostly on mammalian prey (52.8%, SD = 15.9 for residents, 42.0%, SD = 15.6 for transients). Resident coyotes consumed more game birds (21.3%, SD = 11.6 vs 13.7%, SD = 8.8) and less fruit (10.5%, SD = 6.9 vs 21.3%, SD = 10.7) and insects (7.2%, SD = 4.7 vs 14.3%, SD = 8.5) than did transients. Our findings indicate that coyote populations fall on a feeding continuum of omnivory to carnivory in which variability in feeding strategies is influenced by land cover characteristics and space use behaviors.
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Affiliation(s)
- Sarah C. Webster
- Warnell School of Forestry and Natural Resources, University of Georgia, Savannah River Ecology Laboratory, Aiken, South Carolina, United States
| | | | - Michael J. Chamberlain
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, United States
| | | | - James C. Beasley
- Warnell School of Forestry and Natural Resources, University of Georgia, Savannah River Ecology Laboratory, Aiken, South Carolina, United States
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12
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Bastos RF, Condini MV, Barbosa EF, Oliveira RL, Almeida LL, Garcia AM, Hostim-Silva M. Seeing further into the early steps of the endangered atlantic goliath grouper (Epinephelus itajara): Eye lenses high resolution isotopic profiles reveal ontogenetic trophic and habitat shifts. MARINE ENVIRONMENTAL RESEARCH 2024; 198:106517. [PMID: 38657369 DOI: 10.1016/j.marenvres.2024.106517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 04/26/2024]
Abstract
Estuarine mangroves are often considered nurseries for the Atlantic Goliath grouper juveniles. Yet, the contributions of different estuarine primary producers and habitats as sources of organic matter during early ontogenetic development remain unclear. Given the species' critically endangered status and protection in Brazil, obtaining biological samples from recently settled recruits in estuaries is challenging. In this study, we leveraged a local partnership with fishers and used stable isotope (C and N) profiles from the eye lenses of stranded individuals or incidentally caught by fishery to reconstruct the trophic and habitat changes of small juveniles. The eye lens grows by the apposition of protein-rich layers. Once these layers are formed, they become inert, allowing to make inferences on the trophic ecology and habitat use along the development of the individual until its capture. We used correlations between fish size and the entire eye lens size, along with estuarine baselines, to reconstruct the fish size and trophic positions for each of the lens layers obtained. We then used dominant primary producers and basal sources from mangrove sheltered, exposed estuarine and marine habitats to construct an ontogenetic model of trophic and habitat support changes since maternal origins. Our model revealed marine support before the juveniles reached 25 mm (standard length), followed by a rapid increase in reliance on mangrove sheltered sources, coinciding with the expected size at settlement. After reaching 60 mm, individuals began to show variability. Some remained primarily supported by the mangrove sheltered area, while others shifted to rely more on the exposed estuarine area around 150 mm. Our findings indicate that while mangroves are critical for settlement, as Goliath grouper juveniles grow, they can utilize organic matter produced throughout the estuary. This underscores the need for conservation strategies that focus on seascape connectivity, as protecting just one discrete habitat may not be sufficient to preserve this endangered species and safeguard its ecosystem functions.
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Affiliation(s)
- Rodrigo F Bastos
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Programa de Pós-graduação Em Oceanografia Ambiental, Universidade Federal Do Espírito Santo - Av. Fernando Ferrari, 514 - Goiabeiras, Vitória, ES, 29075-910, Brazil.
| | - Mario V Condini
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Programa de Pós-graduação Em Oceanografia Ambiental, Universidade Federal Do Espírito Santo - Av. Fernando Ferrari, 514 - Goiabeiras, Vitória, ES, 29075-910, Brazil
| | - Ester F Barbosa
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil
| | - Rafael L Oliveira
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Programa de Pós-Graduação Em Ciências Biológicas (Biologia Animal - PPGBAN), Departamento de Ciências Biológicas, Universidade Federal Do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil
| | - Lorena L Almeida
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Instituto Meros Do Brasil, Rua Benjamin Constant 67, Conj. 1104, CEP: 80060-020, Curitiba, PR, Brazil
| | - Alexandre M Garcia
- Laboratório de Ictiologia, Instituto de Oceanografia, Universidade Federal Do Rio Grande, Av. Itália Km 8, Carreiros. 96.201-900, Rio Grande, RS, Brazil
| | - Maurício Hostim-Silva
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Programa de Pós-graduação Em Oceanografia Ambiental, Universidade Federal Do Espírito Santo - Av. Fernando Ferrari, 514 - Goiabeiras, Vitória, ES, 29075-910, Brazil; Programa de Pós-Graduação Em Ciências Biológicas (Biologia Animal - PPGBAN), Departamento de Ciências Biológicas, Universidade Federal Do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil; Instituto Meros Do Brasil, Rua Benjamin Constant 67, Conj. 1104, CEP: 80060-020, Curitiba, PR, Brazil
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13
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Tack LFJ, Vonk JA, van Riel MC, de Leeuw JJ, Koopman J, Maathuis MAM, Schilder K, van Hall RL, Huisman J, van der Geest HG. Food webs in isolation: The food-web structure of a freshwater reservoir with armoured shores in a former coastal bay area. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 925:171780. [PMID: 38499096 DOI: 10.1016/j.scitotenv.2024.171780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 03/11/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
Many shallow coastal bays have been closed off from the sea to mitigate the risk of flooding, resulting in coastal reservoir lakes with artificial armoured shorelines. Often these enclosed ecosystems show a persistent decline in biodiversity and ecosystem services, which is likely reflected in their food-web structure. We therefore hypothesize that the food webs of coastal reservoir lakes with armoured shorelines (1) consist of relatively few species with a low food-web connectance and short food chains, and (2) are mainly fuelled by autochthonous organic matter produced in the pelagic zone. To investigate these two hypotheses, we used stable-isotope analysis to determine the food-web structure of lake Markermeer (The Netherlands), a large reservoir lake with armoured shorelines in a former coastal bay area. Contrary to expectation, connectance of the food web in lake Markermeer was comparable to other lakes, while food-chain length was in the higher range. However, the trophic links revealed that numerous macroinvertebrates and fish species in this constructed lake exhibited omnivorous feeding behaviour. Furthermore, in line with our second hypothesis, primary consumers heavily relied on pelagically derived organic matter, while benthic primary production exerted only a minor and seasonal influence on higher trophic levels. Stable-isotope values and the C:N ratio of sediment organic matter in the lake also aligned more closely with phytoplankton than with benthic primary producers. Moreover, terrestrial subsidies of organic matter were virtually absent in lake Markermeer. These findings support the notion that isolation of the lake through shore armouring and the lack of littoral habitats in combination with persistent resuspension of sediments have affected the food web. We argue that restoration initiatives should prioritize the establishment of land-water transition zones, thereby enhancing habitat diversity, benthic primary production, and the inflow of external organic matter while preserving pelagic primary production.
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Affiliation(s)
- Laura F J Tack
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands; Rijkswaterstaat, afdeling Water, Verkeer en Leefomgeving, Lelystad, the Netherlands.
| | - J Arie Vonk
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
| | - Mariëlle C van Riel
- Wageningen Environmental Research, Wageningen University and Research, Wageningen, the Netherlands; Bargerveen Foundation, University of Nijmegen, Nijmegen, the Netherlands
| | - Joep J de Leeuw
- Wageningen Marine Research, Wageningen University and Research, IJmuiden, the Netherlands
| | - Jos Koopman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
| | - Margot A M Maathuis
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands; Wageningen Marine Research, Wageningen University and Research, IJmuiden, the Netherlands
| | - Karen Schilder
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands; Wageningen Marine Research, Wageningen University and Research, IJmuiden, the Netherlands
| | - Rutger L van Hall
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
| | - Harm G van der Geest
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
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14
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Senez-Mello TM, Martins MVA, de Lima Ferreira PA, Figueira R, Castelo WFL, Damasceno FL, Hohenegger J, Pereira E, Duleba W, Gerardes MC. Assessment of anthropogenic pollution in Guanabara Bay (SE Brazil) through biogeochemical data and stable isotope mixing models. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:32972-32997. [PMID: 38671267 DOI: 10.1007/s11356-024-33144-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 03/26/2024] [Indexed: 04/28/2024]
Abstract
This work intends to identify pollution sources along the margins of Guanabara Bay (GB; SE Brazil) through a multiproxy approach and Bayesian stable isotopic mixture model (BSIMM). For this purpose, 33 surface sediment samples were collected and analyzed for granulometry, geochemistry (heavy metals, total organic carbon-TOC, stable isotopes of carbon and nitrogen-δ13C and δ15N, Rock-Eval pyrolysis parameters-REPP), and physicochemical parameters. Metal concentrations (E) dissolved in water (EW), adsorbed by organic matter (EOM) and by Mn hydroxides (EMn), and total extracted concentrations (ET) were analyzed. Sampling was conducted in 2018 after an oil spill from Reduc Oil Refinery. Potential Ecological risk index (PERI), based on metals, classified 85% of the analyzed stations as having moderate to considerable ecological risk. The metals with the potential to cause the highest ecological risk were CdW, CdOM, PbOM, and HgOM. The combination of BSIMM and REPP data was an effective proxy for oil spill detection by indicating the presence of polycyclic aromatic hydrocarbons (PAHs). Relatively high TOC contents suggested that the analyzed stations are eutrophicated environments. BSIMM discriminated three groups of stations with different sources of organic matter (OM), endorsing the result previously shown by the cluster analysis: (A) Niterói region, Botafogo marina, Glória marina, Fiscal and Fundão islands with diffuse sources of OM, including marine phytoplankton and material of continental origin from highly polluted rivers and domestic sewage; (B) region near Fundão and Governador islands and Mangue Channel outlet with OM (≃70%) supplied by highly polluted streams and a small contribution of PAHs; (C) Duque de Caxias and Botafogo-Urca inlet with significant contributions of PAHs, materials from C-3 plants and rivers polluted by urban sewage. Results of linear regressions in conjunction with BSIMM indicate that HgMn and PbOM mainly affect Group A's stations. Although the eastern margin of GB (Niterói; Group A) showed greater oceanic interaction than the other groups, it presented substantial concentrations of metals, potentially harmful (i.e., Hg and Pb) to marine biota and human health.
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Affiliation(s)
- Thaise Machado Senez-Mello
- Faculdade de Geologia (FGEL), Universidade Do Estado Do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil.
- Programa de Pós Graduação Em Dinâmica Dos Oceanos E da Terra, Universidade Federal Fluminense (UFF), Niterói, RJ, Brazil.
| | - Maria Virgínia Alves Martins
- Faculdade de Geologia (FGEL), Universidade Do Estado Do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil
- Geobiosciências, Geoengenharia e Geotecnologias (GeoBioTec), Universidade de Aveiro, Campus de Santiago, Aveiro, Portugal
| | | | - Rubens Figueira
- Geobiosciências, Geoengenharia e Geotecnologias (GeoBioTec), Universidade de Aveiro, Campus de Santiago, Aveiro, Portugal
| | | | - Fabrício Leandro Damasceno
- Faculdade de Geologia (FGEL), Universidade Do Estado Do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil
| | - Johann Hohenegger
- Institut Fur Palaontologie, Universitat Wien, Vienna, Althanstrasse, Austria
| | - Egberto Pereira
- Faculdade de Geologia (FGEL), Universidade Do Estado Do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil
| | - Wânia Duleba
- Escola de Artes, Universidade de São Paulo, Ciências E Humanidades, São Paulo, SP, Brazil
| | - Mauro Cesar Gerardes
- Faculdade de Geologia (FGEL), Universidade Do Estado Do Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil
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15
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Raoult V, Phillips AA, Nelson J, Niella Y, Skinner C, Tilcock MB, Burke PJ, Szpak P, James WR, Harrod C. Why aquatic scientists should use sulfur stable isotope ratios (ẟ 34S) more often. CHEMOSPHERE 2024; 355:141816. [PMID: 38556184 DOI: 10.1016/j.chemosphere.2024.141816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 02/26/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
Over the last few decades, measurements of light stable isotope ratios have been increasingly used to answer questions across physiology, biology, ecology, and archaeology. The vast majority analyse carbon (δ13C) and nitrogen (δ15N) stable isotopes as the 'default' isotopes, omitting sulfur (δ34S) due to time, cost, or perceived lack of benefits and instrumentation capabilities. Using just carbon and nitrogen isotopic ratios can produce results that are inconclusive, uncertain, or in the worst cases, even misleading, especially for scientists that are new to the use and interpretation of stable isotope data. Using sulfur isotope values more regularly has the potential to mitigate these issues, especially given recent advancements that have lowered measurement barriers. Here we provide a review documenting case studies with real-world data, re-analysing different biological topics (i.e. niche, physiology, diet, movement and bioarchaeology) with and without sulfur isotopes to highlight the various strengths of this stable isotope for various applications. We also include a preliminary meta-analysis of the trophic discrimination factor (TDF) for sulfur isotopes, which suggest small (mean -0.4 ± 1.7 ‰ SD) but taxa-dependent mean trophic discrimination. Each case study demonstrates how the exclusion of sulfur comes at the detriment of the results, often leading to very different outputs, or missing valuable discoveries entirely. Given that studies relying on carbon and nitrogen stable isotopes currently underpin most of our understanding of various ecological processes, this has concerning implications. Collectively, these examples strongly suggest that researchers planning to use carbon and nitrogen stable isotopes for their research should incorporate sulfur where possible, and that the new 'default' isotope systems for aquatic science should now be carbon, nitrogen, and sulfur.
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Affiliation(s)
- Vincent Raoult
- Blue Carbon Lab, School of Life and Environmental Science, Deakin University, VIC, Australia; Marine Ecology Group, School of Natural Sciences, Macquarie University, NSW, Australia.
| | - Alexandra A Phillips
- National Center for Ecological Analysis and Synthesis, University of California Santa Barbara, Santa Barbara, CA, USA
| | - James Nelson
- Department of Marine Science, University of Georgia, Athens, GA, USA
| | - Yuri Niella
- Marine Ecology Group, School of Natural Sciences, Macquarie University, NSW, Australia
| | - Christina Skinner
- Marine Spatial Ecology Lab, School of Biological Sciences, University of Queensland, QLD, Australia
| | | | - Patrick J Burke
- Marine Ecology Group, School of Natural Sciences, Macquarie University, NSW, Australia
| | - Paul Szpak
- Department of Anthropology, Trent University, Peterborough, Ontario, Canada
| | - W Ryan James
- Institute of Environment, Florida International University, Miami, FL, USA
| | - Chris Harrod
- Instituto Ciencias Naturales Alexander von Humboldt, Universidad de Antofagasta, Antofagasta, Chile; Millennium Nucleus INVASAL, Concepción, Chile; Universidad de Antofagasta Stable Isotope Facility, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
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16
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Oliveira ACB, Freitas CEC, Pouilly M, Yamamoto KC, Hurd LE, Dehart P, Santos JA, Rezende CE, Almeida MGDE, Siqueira-Souza FK. Can species guilds act as hubs for energy transfer in macrophyte meadows of Amazonian floodplain lakes? AN ACAD BRAS CIENC 2024; 96:e20230327. [PMID: 38597490 DOI: 10.1590/0001-3765202420230327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 07/06/2023] [Indexed: 04/11/2024] Open
Abstract
Aquatic macrophytes are the main autochthonous component of primary production in the Amazon Basin. Floating meadows of these plants support habitats with highly diverse animal communities. Fishes inhabiting these habitats have been assumed to use a broad range of food items and compose a particular food web. We employed carbon (δ13C) and nitrogen (δ15N) stable isotope analysis to draw the trophic structure of these habitats and to trace the energy flow by its trophic levels. Fishes and other animals from 18 independent macrophyte meadows of a floodplain lake of the Solimões River (Amazonia, Brazil) were analyzed. The food web of macrophyte meadows consists of four trophic levels above autotrophic sources. In general, primary consumers exhibited a broader range of food sources than the upper trophic levels. Some fish species depended on a large number of food sources and at the same time are consumed by several predators. The energy transfer from one trophic level to the next was then mainly accomplished by these species concentrating a high-energy flux and acting as hubs in the food web. The broad range of δ13C values observed indicates that the organisms living in the macrophyte meadows utilize a great diversity of autotrophic sources.
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Affiliation(s)
- Ana Cristina B Oliveira
- Universidade Federal do Amazonas, Faculdade de Ciências Agrárias, Departamento de Ciências Pesqueiras, Av. General Rodrigo Otávio, 7200, 69077-000 Manaus, AM, Brazil
| | - Carlos E C Freitas
- Universidade Federal do Amazonas, Faculdade de Ciências Agrárias, Departamento de Ciências Pesqueiras, Av. General Rodrigo Otávio, 7200, 69077-000 Manaus, AM, Brazil
| | - Marc Pouilly
- French National Research Institute Four Sustainable Development (IRD), Biology of Aquatic Organisms and Ecosystems (BOREA), Muséum National d'Histoire Naturelle (MNHN), Paris Sorbonne University, Paris, 75005, France
| | - Kedma Cristine Yamamoto
- Universidade Federal do Amazonas, Faculdade de Ciências Agrárias, Departamento de Ciências Pesqueiras, Av. General Rodrigo Otávio, 7200, 69077-000 Manaus, AM, Brazil
| | - Lawrence Edward Hurd
- Department of Biology, Washington and Lee University, Lexington, Virginia, 24450, USA
| | - Pieter Dehart
- Office of Graduate Studies, University of Wisconsin-Green Bay, Green Bay, Wisconsin, 54311, USA
| | - Jamerson A Santos
- Universidade Federal do Amazonas, Faculdade de Ciências Agrárias, Departamento de Ciências Pesqueiras, Av. General Rodrigo Otávio, 7200, 69077-000 Manaus, AM, Brazil
| | - Carlos Eduardo Rezende
- Universidade Estadual do Norte Fluminense Darcy Ribeiro, Centro de Biociências e Biotecnologia, Laboratório de Ciências Ambientais, Av. Alberto Lamego, 2000, 28103-602 Campos dos Goytacazes, RJ, Brazil
| | - Marcelo G DE Almeida
- Universidade Estadual do Norte Fluminense Darcy Ribeiro, Centro de Biociências e Biotecnologia, Laboratório de Ciências Ambientais, Av. Alberto Lamego, 2000, 28103-602 Campos dos Goytacazes, RJ, Brazil
| | - Flavia Kelly Siqueira-Souza
- Universidade Federal do Amazonas, Faculdade de Ciências Agrárias, Departamento de Ciências Pesqueiras, Av. General Rodrigo Otávio, 7200, 69077-000 Manaus, AM, Brazil
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17
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Martins K, Niella Y, Albuquerque F, Eduardo LN, Oliveira P, Travassos P. Feeding behavior of yellowfin tuna around two insular regions of the western Atlantic Ocean. JOURNAL OF FISH BIOLOGY 2024; 104:1112-1121. [PMID: 38174622 DOI: 10.1111/jfb.15646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 10/27/2023] [Accepted: 12/11/2023] [Indexed: 01/05/2024]
Abstract
The yellowfin tuna is a very abundant tropical tuna species in the western equatorial Atlantic Ocean and an important fishery resource for the Brazilian tuna fleet. In this study we performed stable isotope analysis to better understand the spatial trophodynamics and dietary changes in yellowfin tuna around two insular marine protected areas in Brazil. A total of 65 yellowfin tuna specimens measuring between 47 and 138 cm LT (total length) were sampled around the archipelagos of Fernando de Noronha (FNA; n = 34) and Saint Peter and Saint Paul (SPSPA; n = 31) between July 2018 and September 2019. Bayesian mixing models and generalized additive models were used to investigate the contributions of four different prey items (zooplankton, cephalopods, fish larvae, and flying fish) to yellowfin tuna diet in each area and their potential changes in relation to predator growth. The four prey items were found to have different overall contributions between the two studied areas, with zooplankton being the most important prey in FNA, whereas flying fish was the most relevant prey to the species' diet in SPSPA. Significant changes in the species diet by size were also found, with fish smaller than 90 cm (TL) having a more generalist diet and larger animals relying more on consuming larger and more nutritious prey (i.e., flying fish). Our results suggest that these two marine protected areas play an important role in ocean dynamics, providing important and different foraging grounds for the development of this predator species.
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Affiliation(s)
- Karla Martins
- Laboratório de Ecologia Marinha, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Yuri Niella
- School of Natural Sciences, Macquarie University, Sydney, Australia
| | - Fernanda Albuquerque
- Laboratório de Etologia de Peixes, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | | | - Paulo Oliveira
- Laboratório de Etologia de Peixes, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Paulo Travassos
- Laboratório de Ecologia Marinha, Universidade Federal Rural de Pernambuco, Recife, Brazil
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18
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Lu Z, Yu H, Adu-Gyamfi J, Wang H, Chappell A, Oshunsanya SO, Liu W, Xue T, Heng L. Land management policy shift influenced seasonal variation of erosion-induced nitrogen and phosphorus outputs from intensive agricultural catchment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170590. [PMID: 38311083 DOI: 10.1016/j.scitotenv.2024.170590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/24/2024] [Accepted: 01/29/2024] [Indexed: 02/06/2024]
Abstract
A shift in policy to intensive agricultural production and land management often leads to excessive fertilizer application and accelerated erosion with consequent detrimental effects to water bodies. We investigated the impact of that shift by quantifying the spatial and temporal change in sediment sources and associated total nitrogen (TN) and total phosphorus (TP) pollutants output loads in an intensive agricultural catchment in North China across one year (November 2021-November 2022). We describe the implications of this work for intensive agriculture elsewhere in China and other countries. Seasonal sediment source apportionment was estimated at the catchment outlet using Berillium-7 (7Be) combined with compound-specific stable isotope (CSSI) signatures from sources and sediments. Diagnostic 'fingerprints' in MixSIAR were used to discriminate sediment sources between forest and crop farmland converted from forest (F + C(F)), crop farmland (C), and vegetable farmland (V). Our study identified F + C(F) as the dominant sediment source (mean 55.24 ± 2.91 %), intermediate on V (mean 30.06 ± 2.20 %), and least on C (mean 14.70 ± 2.13 %). Sedimentation ranged from 37.98 ± 3.02 to 89.60 ± 12.68 t·ha-1·event-1 and coincided with shifted land use policy and rainfall distribution. The TN and TP in sediment were both mainly derived from F + C(F) (averaged 22.27 ± 4.26 t·event-1 and 11.62 ± 2.28 t·event-1) and least from V (averaged 1.63 ± 0.29 and 2.09 ± 0.33 t·event-1). Despite being a significant sediment source, V contributed little sediment TN and TP input for eutrophication. Our findings imply that F + C(F) are diffuse sources of catchment pollution over the short term. These results describe the successful use of CSSI and 7Be to cost-effectively quantify the seasonal variation of sediment TN and TP loads from land-use-specific sources in the catchment under shifting land management policy in China with potential for use elsewhere. These findings enable soil conservation strategies and land management practices optimized for implementing targeted pollutant abatement initiatives in intensive agriculture in China and elsewhere.
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Affiliation(s)
- Zhaoyang Lu
- Agricultural Clean Watershed Research Group, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences (CAAS), Haidian District, 100081 Beijing, China
| | - Hanqing Yu
- Agricultural Clean Watershed Research Group, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences (CAAS), Haidian District, 100081 Beijing, China.
| | | | - Hongyu Wang
- Agricultural Clean Watershed Research Group, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences (CAAS), Haidian District, 100081 Beijing, China
| | - Adrian Chappell
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
| | - Suarau Odutola Oshunsanya
- Agricultural Clean Watershed Research Group, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences (CAAS), Haidian District, 100081 Beijing, China; Department of Agronomy, University of Ibadan, Nigeria
| | - Wenxiang Liu
- Agricultural Clean Watershed Research Group, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences (CAAS), Haidian District, 100081 Beijing, China; Chongqing Branch Institute, Changjiang River Scientific Research Institute, 400026 Chongqing, China
| | - Tingting Xue
- Agricultural Clean Watershed Research Group, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences (CAAS), Haidian District, 100081 Beijing, China
| | - Lee Heng
- International Atomic Energy Agency, Vienna, Austria
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19
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Leighton GRM, Froneman PW, Serieys LEK, Bishop JM. Sustained use of marine subsidies promotes niche expansion in a wild felid. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169912. [PMID: 38184259 DOI: 10.1016/j.scitotenv.2024.169912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/18/2023] [Accepted: 01/02/2024] [Indexed: 01/08/2024]
Abstract
The use of marine subsidies by terrestrial predators can facilitate substantial transfer of nutrients between marine and terrestrial ecosystems. Marine resource subsidies may have profound effects on predator ecology, influencing population and niche dynamics. Expanding niches of top consumers can impact ecosystem resilience and interspecific interactions, affecting predator-prey dynamics and competition. We investigate the occurrence, importance, and impact of marine resources on trophic ecology and niche dynamics in a highly generalist predator, the caracal (Caracal caracal), on the Cape Peninsula, South Africa. Caracals have flexible diets, feeding across a wide range of terrestrial and aquatic prey. We use carbon and nitrogen stable isotope analysis of fur samples (n = 75) to understand trophic position and niche shifts in coastal and inland foragers, as well as the implications of a diet rich in marine resources. We found significant differences in isotope signatures between these groups, with higher δ13C (P < 0.05) and δ15N values (P < 0.01) in coastal foragers. Isotope mixing models reveal that these elevated signatures were due to non-terrestrial food subsidies, where approximately a third of coastal foraging caracal diet comprised marine prey. The addition of marine prey species to diet increased both the trophic level and isotope niche size of coastal foraging caracals, with potential impacts on prey populations and competition. Our results suggest that marine prey are an important dietary resource for coastal foraging caracals, where seabirds, including two endangered species, are a major component of their diet. However, there are likely risks associated with these resource benefits, as routine consumption of seabirds is linked with higher pollutant burdens, particularly metals. Increased encounters between this terrestrial predator and seabirds may be a result of increased mainland colonies due to changes in habitat availability and the highly opportunistic and generalist foraging behaviour of a native predator.
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Affiliation(s)
- Gabriella R M Leighton
- Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa; Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Rondebosch, Cape Town 7701, South Africa.
| | - P William Froneman
- Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
| | - Laurel E K Serieys
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Rondebosch, Cape Town 7701, South Africa; Panthera, NY, New York, USA; Cape Leopard Trust, Cape Town, South Africa
| | - Jacqueline M Bishop
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
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20
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Davis MJ, Woo I, De La Cruz SEW, Ellings CS, Hodgson S, Nakai G. Allochthonous marsh subsidies enhances food web productivity in an estuary and its surrounding ecosystem mosaic. PLoS One 2024; 19:e0296836. [PMID: 38421974 PMCID: PMC10903911 DOI: 10.1371/journal.pone.0296836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 12/20/2023] [Indexed: 03/02/2024] Open
Abstract
Terrestrial organic matter is believed to play an important role in promoting resilient estuarine food webs, but the inherent interconnectivity of estuarine systems often obscures the origins and importance of these terrestrial inputs. To determine the relative contributions of terrestrial (allochthonous) and aquatic (autochthonous) organic matter to the estuarine food web, we analyzed carbon, nitrogen, and sulfur stable isotopes from multiple trophic levels, environmental strata, and habitats throughout the estuarine habitat mosaic. We used a Bayesian stable isotope mixing model (SIMM) to parse out relationships among primary producers, invertebrates, and a pelagic and demersal fish species (juvenile Chinook salmon and sculpin, respectively). The study was carried out in the Nisqually River Delta (NRD), Washington, USA, a recently-restored, macrotidal estuary with a diverse habitat mosaic. Plant groupings of macroalgae, eelgrass, and tidal marsh plants served as the primary base components of the NRD food web. About 90% of demersal sculpin diets were comprised of benthic and pelagic crustaceans that were fed by autochthonous organic matter contributions from aquatic vegetation. Juvenile salmon, on the other hand, derived their energy from a mix of terrestrial, pelagic, and benthic prey, including insects, dipterans, and crustaceans. Consequently, allochthonous terrestrial contributions of organic matter were much greater for salmon, ranging between 26 and 43%. These findings demonstrate how connectivity among estuarine habitat types and environmental strata facilitates organic matter subsidies. This suggests that management actions that improve or restore lateral habitat connectivity as well as terrestrial-aquatic linkages may enhance allochthonous subsidies, promoting increased prey resources and ecosystem benefits in estuaries.
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Affiliation(s)
- Melanie J. Davis
- U.S. Geological Survey, Western Ecological Research Center, Olympia Substation, Olympia, Washington, United States of America
| | - Isa Woo
- U.S. Geological Survey, Western Ecological Research Center, San Francisco Bay Estuary Field Station, Moffett Field, California, United States of America
| | - Susan E. W. De La Cruz
- U.S. Geological Survey, Western Ecological Research Center, San Francisco Bay Estuary Field Station, Moffett Field, California, United States of America
| | - Christopher S. Ellings
- Nisqually Indian Tribe, Department of Natural Resources, Olympia, Washington, United States of America
| | - Sayre Hodgson
- Nisqually Indian Tribe, Department of Natural Resources, Olympia, Washington, United States of America
| | - Glynnis Nakai
- U.S. Fish and Wildlife Service, Billy Frank Jr. Nisqually National Wildlife Refuge, Olympia, Washington, United States of America
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21
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de Carvalho DR, Ferreira FF, Dergam JA, Moreira MZ, Pompeu PS. Food web structure of fish communities of Doce River, 5 years after the Fundão dam failure. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:300. [PMID: 38401000 DOI: 10.1007/s10661-024-12395-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 01/29/2024] [Indexed: 02/26/2024]
Abstract
The rupture of the Fundão dam is considered the largest mining failure in history, which had a particularly detrimental impact on fish populations, as the mud from the ore tailings significantly altered the water quality and habitat of Doce River basin. This study aimed to assess the trophic structure of fish communities in areas impacted and not impacted by the dam rupture in the Doce River basin. To evaluate the food web structure, community-wide trophic niche, and trophic positions of fish, stable isotopes of carbon (δ13C) and nitrogen (δ15N) were utilized across ten sites (seven impacted and three control). In general, fish appeared to assimilate resources such as invertebrates, algae, and periphyton, although the importance of each resource varied among sites. The site closest to the dam rupture exhibited a more simplified trophic structure compared to the control sites and those nearer the river mouth. In this site, most fish species occupied a similar trophic position. Trophic niches also exhibited the greatest dissimilarity between the site closest to the dam failure and those farther away from it, with an expansion of trophic niche breadth observed with an increase in the distance from the dam rupture. Our study provided valuable insights into the trophic structure of fish communities within the Doce River basin, shedding light on the trophic ecology of the 59 fish species investigated. We also emphasize the importance of our study for future assessments of ore tailings dam failure disasters and evaluating the effectiveness of mitigation measures for Doce River basin recovery.
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Affiliation(s)
- Débora Reis de Carvalho
- Laboratório de Ecologia de Peixes, Programa de Pós-Graduação Em Ecologia Aplicada, Departamento de Ecologia E Conservação, Universidade Federal de Lavras, Campus Universitário, Caixa Postal 3037, Lavras, MG, CEP 37200-000, Brazil.
| | | | - Jorge A Dergam
- Laboratório de Sistemática Molecular Beagle, Departamento de Biologia Animal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Marcelo Zacharias Moreira
- Laboratório de Ecologia Isotópica, Centro de Energia Nuclear Na Agricultura - CENA, Universidade de São Paulo, Av. Centenário, 303, Caixa Postal 96, Piracicaba, SP, CEP 13400-970, Brazil
| | - Paulo Santos Pompeu
- Laboratório de Ecologia de Peixes, Programa de Pós-Graduação Em Ecologia Aplicada, Departamento de Ecologia E Conservação, Universidade Federal de Lavras, Campus Universitário, Caixa Postal 3037, Lavras, MG, CEP 37200-000, Brazil
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22
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Bouchard É, Bonin M, Sharma R, Hernández-Ortiz A, Gouin GG, Simon A, Leighton P, Jenkins E. Use of stable isotopes to reveal trophic relationships and transmission of a food-borne pathogen. Sci Rep 2024; 14:2812. [PMID: 38307906 PMCID: PMC10837197 DOI: 10.1038/s41598-024-53369-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 01/31/2024] [Indexed: 02/04/2024] Open
Abstract
Predators in food webs are valuable sentinel species for zoonotic and multi-host pathogens such as Toxoplasma gondii. This protozoan parasite is ubiquitous in warm-blooded vertebrates, and can have serious adverse effects in immunocompromised hosts and foetuses. In northern ecosystems, T. gondii is disproportionately prevalent in Inuit people and wildlife, in part due to multiple routes of transmission. We combined data on T. gondii infection in foxes from Nunavik (northern Québec, Canada) with stable isotope data tracking trophic relationships between foxes and several of their main prey species. Red (Vulpes vulpes) and Arctic fox (Vulpes lagopus) carcasses were collected by local trappers from 2015 to 2019. We used magnetic capture PCR to detect DNA of T. gondii in heart and brain tissues, and enzyme-linked immunosorbent assay to detect antibodies in blood. By linking infection status with diet composition, we showed that infected foxes had a higher probability of consuming aquatic prey and migratory geese, suggesting that these may be important sources of T. gondii transmission in the Arctic. This use of stable isotopes to reveal parasite transmission pathways can be applied more broadly to other foodborne pathogens, and provides evidence to assess and mitigate potential human and animal health risks associated with T. gondii in northern ecosystems.
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Affiliation(s)
- Émilie Bouchard
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK, S7N 5B4, Canada.
- Research Group on Epidemiology of Zoonoses and Public Health (GREZOSP), Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, J2S 2M2, Canada.
- Centre de recherche en santé publique de l'Université de Montréal et du CIUSSS du Centre-Sud-de-l'Île-de-Montréal, Montreal, QC, H2L 2W5, Canada.
| | - Michaël Bonin
- Département de Biologie, Centre d'études nordiques, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Rajnish Sharma
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK, S7N 5B4, Canada
| | - Adrián Hernández-Ortiz
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK, S7N 5B4, Canada
| | - Géraldine-G Gouin
- Nunavik Research Centre, Makivvik Corporation, Kuujjuaq, QC, J0M 1C0, Canada
| | - Audrey Simon
- Research Group on Epidemiology of Zoonoses and Public Health (GREZOSP), Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, J2S 2M2, Canada
| | - Patrick Leighton
- Research Group on Epidemiology of Zoonoses and Public Health (GREZOSP), Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, J2S 2M2, Canada
- Centre de recherche en santé publique de l'Université de Montréal et du CIUSSS du Centre-Sud-de-l'Île-de-Montréal, Montreal, QC, H2L 2W5, Canada
| | - Emily Jenkins
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK, S7N 5B4, Canada
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23
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Mikkelsen AJ, Hobson KA, Sergiel A, Hertel AG, Selva N, Zedrosser A. Testing foraging optimization models in brown bears: Time for a paradigm shift in nutritional ecology? Ecology 2024; 105:e4228. [PMID: 38071743 DOI: 10.1002/ecy.4228] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 10/30/2023] [Indexed: 12/31/2023]
Abstract
How organisms obtain energy to survive and reproduce is fundamental to ecology, yet researchers use theoretical concepts represented by simplified models to estimate diet and predict community interactions. Such simplistic models can sometimes limit our understanding of ecological principles. We used a polyphagous species with a wide distribution, the brown bear (Ursus arctos), to illustrate how disparate theoretical frameworks in ecology can affect conclusions regarding ecological communities. We used stable isotope measurements (δ13 C, δ15 N) from hairs of individually monitored bears in Sweden and Bayesian mixing models to estimate dietary proportions of ants, moose, and three berry species to compare with other brown bear populations. We also developed three hypotheses based on predominant foraging literature, and then compared predicted diets to field estimates. Our three models assumed (1) bears forage to optimize caloric efficiency (optimum foraging model), predicting bears predominately eat berries (~70% of diet) and opportunistically feed on moose (Alces alces) and ants (Formica spp. and Camponotus spp; ~15% each); (2) bears maximize meat intake (maximizing fitness model), predicting a diet of 35%-50% moose, followed by ants (~30%), and berries (~15%); (3) bears forage to optimize macronutrient balance (macronutrient model), predicting a diet of ~22% (dry weight) or 17% metabolizable energy from proteins, with the rest made up of carbohydrates and lipids (~49% and 29% dry matter or 53% and 30% metabolizable energy, respectively). Bears primarily consumed bilberries (Vaccinium myrtillus; 50%-55%), followed by lingonberries (V. vitis-idaea; 22%-30%), crowberries (Empetrum nigrum; 8%-15%), ants (5%-8%), and moose (3%-4%). Dry matter dietary protein was lower than predicted by the maximizing fitness model and the macronutrient balancing model, but protein made up a larger proportion of the metabolizable energy than predicted. While diets most closely resembled predictions from optimal foraging theory, none of the foraging hypotheses fully described the relationship between foraging and ecological niches in brown bears. Acknowledging and broadening models based on foraging theories is more likely to foster novel discoveries and insights into the role of polyphagous species in ecosystems and we encourage this approach.
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Affiliation(s)
- Ashlee J Mikkelsen
- Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Bø, Norway
| | - Keith A Hobson
- Environment and Climate Change Canada, Saskatoon, Saskatchewan, Canada
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Agnieszka Sergiel
- Institute of Nature Conservation, Polish Academy of Sciences, Krakow, Poland
| | - Anne G Hertel
- Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Bø, Norway
- Department of Biology, Ludwig Maximilians University of Munich, Planegg, Germany
| | - Nuria Selva
- Institute of Nature Conservation, Polish Academy of Sciences, Krakow, Poland
| | - Andreas Zedrosser
- Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Bø, Norway
- Department of Integrative Biology, University of Natural Recourses and Applied Life Sciences, Vienna, Austria
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24
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Lövei GL, Ferrante M. The Use and Prospects of Nonlethal Methods in Entomology. ANNUAL REVIEW OF ENTOMOLOGY 2024; 69:183-198. [PMID: 37669564 DOI: 10.1146/annurev-ento-120220-024402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Arthropods are declining globally, and entomologists ought to be in the forefront of protecting them. However, entomological study methods are typically lethal, and we argue that this makes the ethical status of the profession precarious. Lethal methods are used in most studies, even those that aim to support arthropod conservation. Additionally, almost all collecting methods result in bycatch, and a first step toward less destructive research practices is to minimize bycatch and/or ensure its proper storage and use. In this review, we describe the available suite of nonlethal methods with the aim of promoting their use. We classify nonlethal methods into (a) reuse of already collected material, (b) methods that are damaging but not lethal, (c) methods that modify behavior, and (d) true nonlethal methods. Artificial intelligence and miniaturization will help to extend the nonlethal methodological toolkit, but the need for further method development and testing remains.
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Affiliation(s)
- Gábor L Lövei
- Department of Agroecology, Flakkebjerg Research Centre, Aarhus University, Slagelse, Denmark;
- Hungarian Research Network Anthropocene Ecology Research Group, Debrecen University, Debrecen, Hungary
| | - Marco Ferrante
- Functional Agrobiodiversity, Department of Crop Sciences, University of Göttingen, Germany;
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25
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Giraldo C, Cresson P, MacKenzie K, Fontaine V, Loots C, Delegrange A, Lefebvre S. Insights into planktonic food-web dynamics through the lens of size and season. Sci Rep 2024; 14:1684. [PMID: 38243111 PMCID: PMC10798955 DOI: 10.1038/s41598-024-52256-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/16/2024] [Indexed: 01/21/2024] Open
Abstract
Knowledge of the trophic structure and variability of planktonic communities is a key factor in understanding food-web dynamics and energy transfer from zooplankton to higher trophic levels. In this study, we investigated how stable isotopes of mesozooplankton species varied seasonally (winter, spring, autumn) in relation to environmental factors and plankton size classes in a temperate coastal ecosystem. Our results showed that spring is characterized by the strongest vertical and size-structured plankton food-web, mainly fueled by the phytoplankton bloom. As a result, spring displayed the largest isotopic niche space and trophic divergence among species. On the contrary, both pelagic and benthic-derived carbon influenced low productive seasons (winter and autumn), resulting in more generalist strategies (trophic redundancy). Stable isotope mixing models were used to explore how different seasonal structures influenced the overall food web up to predatory plankton (i.e., mysids, chaetognaths, and fish larvae). Different feeding strategies were found in spring, with predators having either a clear preference for larger prey items (> 1 mm, for herring and dab larvae) or a more generalist diet (sprat and dragonets larvae). During low productive seasons, predators seemed to be more opportunistic, feeding on a wide range of size classes but focusing on smaller prey. Overall, the food-web architecture of plankton displayed different seasonal patterns linked to components at the base of the food web that shaped the main energy fluxes, either from phytoplankton or recycled material. Additionally, these patterns extended to carnivorous plankton, such as fish larvae, emphasizing the importance of bottom-up processes.
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Affiliation(s)
- Carolina Giraldo
- IFREMER, HMMN - Unité halieutique Manche-Mer du Nord, 62200, Boulogne sur mer, France.
| | - Pierre Cresson
- IFREMER, HMMN - Unité halieutique Manche-Mer du Nord, 62200, Boulogne sur mer, France
| | - Kirsteen MacKenzie
- IFREMER, HMMN - Unité halieutique Manche-Mer du Nord, 62200, Boulogne sur mer, France
| | - Virginie Fontaine
- IFREMER, HMMN - Unité halieutique Manche-Mer du Nord, 62200, Boulogne sur mer, France
- Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, IRD, UMR 8187 - LOG - Laboratoire d'Océanologie et de Géosciences, 59000, Lille, France
| | - Christophe Loots
- IFREMER, HMMN - Unité halieutique Manche-Mer du Nord, 62200, Boulogne sur mer, France
| | - Alice Delegrange
- Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, IRD, UMR 8187 - LOG - Laboratoire d'Océanologie et de Géosciences, 59000, Lille, France
| | - Sébastien Lefebvre
- Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, IRD, UMR 8187 - LOG - Laboratoire d'Océanologie et de Géosciences, 59000, Lille, France
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26
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Smith IA, Templer PH, Hutyra LR. Water sources for street trees in mesic urban environments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168411. [PMID: 37939949 DOI: 10.1016/j.scitotenv.2023.168411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/20/2023] [Accepted: 11/05/2023] [Indexed: 11/10/2023]
Abstract
Street trees support climate resiliency through a variety of pathways, such as offsetting urban heat and attenuating storm water runoff. While urban trees in arid and semiarid ecosystems have been shown to take up water from irrigation, it is unknown where street trees in mesic cities obtain their water. In this study, we use natural abundance stable isotopes to estimate the proportional sources of water taken up by Acer platanoides street trees in Boston, Massachusetts, United States, including precipitation, irrigation, groundwater, and wastewater. We use Bayesian multisource mixing models to estimate water sources by comparing the natural abundance isotopic ratios of hydrogen and oxygen across potential water sources with water extracted from tree stem samples. We find that during the summer of 2021, characterized by anomalously high rainfall, street trees predominantly utilized water from precipitation. Precipitation accounted for 72.3 % of water extracted from trees sampled in August and 65.6 % from trees sampled in September. Of the precipitation taken up by street trees, most water was traced back to large storm events in July, with July rainfall alone accounting for up to 84.0 % of water found within street trees. We find strong relationships between canopy cover fractions and the proportion of precipitation lost to evapotranspiration across the study domain, supporting the conclusion that tree planting initiatives result in storm water mitigation benefits due to utilization of water from precipitation by urban vegetation. However, while the mature trees studied here currently support their water demand from precipitation, the dependency of street trees on precipitation in mesic cities may lead to increased water stress in a changing climate characterized by a higher frequency and severity of drought.
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Affiliation(s)
- Ian A Smith
- Boston University, Department of Earth & Environment, 685 Commonwealth Ave., Boston, MA 02215, USA.
| | - Pamela H Templer
- Boston University, Department of Biology, 5 Cummington Mall, Boston, MA 02215, USA
| | - Lucy R Hutyra
- Boston University, Department of Earth & Environment, 685 Commonwealth Ave., Boston, MA 02215, USA
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27
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Thibault M, Letourneur Y, Cleguer C, Bonneville C, Briand MJ, Derville S, Bustamante P, Garrigue C. C and N stable isotopes enlighten the trophic behaviour of the dugong (Dugong dugon). Sci Rep 2024; 14:896. [PMID: 38195771 PMCID: PMC10776846 DOI: 10.1038/s41598-023-50578-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/21/2023] [Indexed: 01/11/2024] Open
Abstract
The dugong (Dugong dugon), a large marine mammal herbivore of the Indo-Pacific, is vulnerable to extinction at a global scale due to a combination of human-related threats including habitat degradation. The species forages on seagrass habitats (marine phanerogams) and plays a key role in the functioning and sensitivity of these declining coastal ecosystems. The trophic behaviour and plasticity of dugong populations in response to extrinsic and intrinsic factors are therefore crucial features to both dugong and seagrass conservation. Yet, this knowledge remains limited to few visual observations and analyses of mouth, stomach or faecal contents of stranded individuals. We take advantage of a long-term monitoring of stranded individuals from the endangered New Caledonian population to depict features of dugongs' trophic ecology from Carbon and Nitrogen stable isotopes. A total of 59 dugong skin samples were used to portrait the stable isotope niche of dugongs according to their sex and maturity. In light of previous work conducted in New Caledonia, a subset of these samples was used to model the trophic mix of dugong males and females. Our stable isotope mixing models used C and N isotope values of 10 taxa bbelonging to five divisions of metazoans, plants, and chromists. Our results represent the first estimate of the species dietary niche in the isotopic space. They suggest that the diet of dugong calves overlaps more with that of adult females (δ13C: - 6.38 ± 1.13 ‰; δ15N: 2.49 ± 1.10 ‰) than males (δ13C: - 5.92 ± 1.10 ‰; δ15N: 3.69 ± 1.28 ‰). Further, we highlight differences in the expected trophic mix of dugong adult males and females. From these, we formulate a sex-specific foraging behaviour hypothesis in dugongs, whereby lactating females could forage over smaller spatial ranges but more diverse food sources thanmales. The study emphasizes the importance of long-term stranding monitoring programs to study the ecology of marine mammals.. Finally, it depicts an ecological feature that may contribute to the sensitivity of vulnerable dugongs to ongoing changes on tropical coastal ecosystems.
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Affiliation(s)
- Martin Thibault
- Centre d'Écologie et des Sciences de la Conservation (CESCO), Muséum National d'Histoire Naturelle, Station de Biologie Marine, 1 Place de la Croix, 29900, Concarneau, France.
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia.
| | - Yves Letourneur
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia
| | - Christophe Cleguer
- Centre for Tropical Water and Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville, Australia
| | - Claire Bonneville
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia
| | - Marine J Briand
- CRIOBE, USR 3278 EPHE-CNRS-UPVD, LabEx « Corail », PSL Research University, Université de Perpignan, Avenue Paul Alduy, 66860, Perpignan Cedex, France
| | - Solène Derville
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia
- Opération Cétacés, BP 12827, 98802, Nouméa, New Caledonia
| | - Paco Bustamante
- Littoral Environnement Et Sociétés (LIENSs), UMR 7266, CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, 17000, La Rochelle, France
| | - Claire Garrigue
- UMR ENTROPIE (UR-IRD-IFREMER-CNRS-UNC), Labex-CORAIL, 98800, Nouméa, New Caledonia
- Opération Cétacés, BP 12827, 98802, Nouméa, New Caledonia
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Bollinger E, Zubrod JP, Englert D, Graf N, Weisner O, Kolb S, Schäfer RB, Entling MH, Schulz R. The influence of season, hunting mode, and habitat specialization on riparian spiders as key predators in the aquatic-terrestrial linkage. Sci Rep 2023; 13:22950. [PMID: 38135811 PMCID: PMC10746743 DOI: 10.1038/s41598-023-50420-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 12/19/2023] [Indexed: 12/24/2023] Open
Abstract
Freshwater ecosystems subsidize riparian zones with high-quality nutrients via the emergence of aquatic insects. Spiders are dominant consumers of these insect subsidies. However, little is known about the variation of aquatic insect consumption across spiders of different hunting modes, habitat specializations, seasons, and systems. To explore this, we assembled a large stable isotope dataset (n > 1000) of aquatic versus terrestrial sources and six spider species over four points in time adjacent to a lotic and a lentic system. The spiders represent three hunting modes each consisting of a wetland specialist and a habitat generalist. We expected that specialists would feed more on aquatic prey than their generalist counterparts. Mixing models showed that spiders' diet consisted of 17-99% of aquatic sources, with no clear effect of habitat specialization. Averaged over the whole study period, web builders (WB) showed the highest proportions (78%) followed by ground hunters (GH, 42%) and vegetation hunters (VH, 31%). Consumption of aquatic prey was highest in June and August, which is most pronounced in GH and WBs, with the latter feeding almost entirely on aquatic sources during this period. Additionally, the elevated importance of high-quality lipids from aquatic origin during fall is indicated by elemental analyses pointing to an accumulation of lipids in October, which represent critical energy reserves during winter. Consequently, this study underlines the importance of aquatic prey irrespective of the habitat specialization of spiders. Furthermore, it suggests that energy flows vary substantially between spider hunting modes and seasons.
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Affiliation(s)
- Eric Bollinger
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany.
| | - Jochen P Zubrod
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
- Zubrod Environmental Data Science, Ostring 24a, D-76829, Landau, Germany
| | - Dominic Englert
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Nadin Graf
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Oliver Weisner
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Sebastian Kolb
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Ralf B Schäfer
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Martin H Entling
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Ralf Schulz
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
- Eußerthal Ecosystem Research Station, RPTU Kaiserslautern-Landau, Birkenthalstraße 13, D-76857, Eußerthal, Germany
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Guo F, Fry B, Yan K, Huang J, Zhao Q, O'Mara K, Li F, Gao W, Kainz MJ, Brett MT, Bunn SE, Zhang Y. Assessment of the impact of dams on aquatic food webs using stable isotopes: Current progress and future challenges. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:167097. [PMID: 37716688 DOI: 10.1016/j.scitotenv.2023.167097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/10/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
Dams have disrupted natural river systems worldwide and although population and community level effects on aquatic biota have been well documented, food web responses remain poorly understood and difficult to characterize. The application of stable isotope analysis (SIA) provides a means to assess the effect of dams on food webs. Here we review the effect of dams on aquatic food webs using SIA, aiming to detect knowledge gaps in the field of dam impacts on aquatic food webs and propose a conceptual framework to help formulate hypotheses about dam impacts on food webs guided by food web theory. Dams can affect aquatic food webs via two pathways: a bottom-up pathway with altered basal food sources and their transfer to consumers through changes in flow, nutrients, temperature and sediment, and a top-down pathway with consumer species composition altered mainly through habitat fragmentation and related physiochemical changes. Taking these mechanisms into consideration, the impact of dams on food web attributes derived from SIA was evaluated. These studies generally apply mixing models to determine how dams alter the dominant carbon sources supporting food webs, use δ15N to examine how dams alter food-chain length, or use Layman metrics of isotope variability to assess niche changes for invertebrate and fish assemblages. Most studies compare the patterns of SIA metrics spatially (e.g. upstream vs reservoir vs downstream of dams; regulated vs unregulated rivers) and temporally (before vs after dam construction), without explicit hypotheses and/or links to theoretical concepts of food webs. We propose several steps to make SIA studies of dam impacts more rigorous and enhance their potential for producing novel insights. Future studies should quantify the shape and strength of the effect of dams on SIA-measured food web response, be conducted at larger temporal and spatial scales (particularly along the river longitudinal continuum and the lateral connected ecosystems (e.g., floodplains)), and consider effects of dams on food web resilience and tipping points.
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Affiliation(s)
- Fen Guo
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China.
| | - Brian Fry
- Australian Rivers Institute, Griffith University, Nathan, Qld 4109, Australia
| | - Keheng Yan
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Juan Huang
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Qian Zhao
- Institute of Environment and Ecology, Shandong Normal University, Jinan 250358, China
| | - Kaitlyn O'Mara
- Australian Rivers Institute, Griffith University, Nathan, Qld 4109, Australia
| | - Feilong Li
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Wei Gao
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Martin J Kainz
- WasserCluster Lunz - Inter-University Centre for Aquatic Ecosystem Research, Lunz am See, Austria
| | - Michael T Brett
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Stuart E Bunn
- Australian Rivers Institute, Griffith University, Nathan, Qld 4109, Australia
| | - Yuan Zhang
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
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30
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Huang R, He J, Wang N, Christakos G, Gu J, Song L, Luo J, Agusti S, Duarte CM, Wu J. Carbon sequestration potential of transplanted mangroves and exotic saltmarsh plants in the sediments of subtropical wetlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166185. [PMID: 37591400 DOI: 10.1016/j.scitotenv.2023.166185] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 08/07/2023] [Accepted: 08/07/2023] [Indexed: 08/19/2023]
Abstract
Coastal blue carbon ecosystems offer promising benefits for both climate change mitigation and adaptation. While there have been widespread efforts to transplant mangroves from the tropics to the subtropics and to introduce exotic saltmarsh plants like Spartina alterniflora in China, few studies have thoroughly quantified the chronological records of carbon sequestration with different organic carbon (OC) sources. To understand how variations in OC sources can affect the carbon sequestration potential of coastal wetland environment over time, we conducted a study on typical islands with two scenarios: S. alterniflora invasion and mangrove transplantation. Our study determined chronological records of carbon sequestration and storage from five sediment profiles and traced changes in the OC sources using carbon stable isotope (δ13C) and C:N ratios in response to these scenarios. The S. alterniflora invasion resulted in an 84 ± 19 % increase in the OC burial rate compared to unvegetated mudflats, while mangrove transplantation resulted in a 167 ± 74 % increase in the OC burial rate compared to unvegetated mudflats. S. alterniflora and mangroves showed greater carbon sequestration potential in areas with high supplies of suspended particulate matter, while mangroves needed to grow to a certain scale to display obvious carbon sequestration benefits. In the mangrove saltmarsh ecotone, mature mangrove habitats exhibited resistance to the S. alterniflora invasion, while mangrove transplantation in the environment invaded by S. alterniflora had a significant effect on OC contribution. Besides, plant-derived OC can be exported to the surrounding environment due to the rapid turnover of sediments. The blue carbon chronosequence-based estimation of OC sources and burial rates provides a useful reference for establishing carbon accounting policies.
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Affiliation(s)
- Runqiu Huang
- Ocean College, Zhejiang University, Zhoushan, China
| | - Junyu He
- Ocean College, Zhejiang University, Zhoushan, China; Joint Center for Blue Carbon Research, Ocean Academy, Zhejiang University, Zhoushan, China
| | - Nan Wang
- Ocean College, Zhejiang University, Zhoushan, China
| | | | - Jiali Gu
- Ocean College, Zhejiang University, Zhoushan, China
| | - Li Song
- Ocean College, Zhejiang University, Zhoushan, China
| | - Ji Luo
- Ocean College, Zhejiang University, Zhoushan, China
| | - Susana Agusti
- Red Sea Research Center (RSRC), King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Carlos M Duarte
- Red Sea Research Center (RSRC), King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Jiaping Wu
- Ocean College, Zhejiang University, Zhoushan, China; Joint Center for Blue Carbon Research, Ocean Academy, Zhejiang University, Zhoushan, China.
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31
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Nash LN, Kratina P, Recalde FC, Jones JI, Izzo T, Romero GQ. Tropical and temperate differences in the trophic structure and aquatic prey use of riparian predators. Ecol Lett 2023; 26:2122-2134. [PMID: 37807844 DOI: 10.1111/ele.14322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 09/18/2023] [Accepted: 09/19/2023] [Indexed: 10/10/2023]
Abstract
The influence of aquatic resource-inputs on terrestrial communities is poorly understood, particularly in the tropics. We used stable isotope analysis of carbon and nitrogen to trace aquatic prey use and quantify the impact on trophic structure in 240 riparian arthropod communities in tropical and temperate forests. Riparian predators consumed more aquatic prey and were more trophically diverse in the tropics than temperate regions, indicating tropical riparian communities are both more reliant on and impacted by aquatic resources than temperate communities. This suggests they are more vulnerable to disruption of aquatic-terrestrial linkages. Although aquatic resource use declined strongly with distance from water, we observed no correlated change in trophic structure, suggesting trophic flexibility to changing resource availability within riparian predator communities in both tropical and temperate regions. Our findings highlight the importance of aquatic resources for riparian communities, especially in the tropics, but suggest distance from water is less important than resource diversity in maintaining terrestrial trophic structure.
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Affiliation(s)
- Liam N Nash
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Pavel Kratina
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Fátima C Recalde
- Laboratory of Multitrophic Interactions and Biodiversity, Department of Animal Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - John Iwan Jones
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK
| | - Thiago Izzo
- Laboratório de Ecologia de Comunidades, Departamento de Botânica e Ecologia, Universidade Federal do Mato Grosso, Mato Grosso, Brazil
| | - Gustavo Q Romero
- Laboratory of Multitrophic Interactions and Biodiversity, Department of Animal Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
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32
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Pilecky M, Wassenaar LI, Taipale S, Kainz MJ. Protocols for sample preparation and compound-specific stable-isotope analyses (δ 2H, δ 13C) of fatty acids in biological and environmental samples. MethodsX 2023; 11:102283. [PMID: 38098777 PMCID: PMC10719507 DOI: 10.1016/j.mex.2023.102283] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 07/07/2023] [Indexed: 12/17/2023] Open
Abstract
Compound-specific stable-isotope analysis (CSIA) of fatty acids is a powerful tool to better understand the trophic transfer of fatty acids and their biochemical fate in and across ecosystems, including tracing animal migration and understanding physiological processes. The non-exchangeable nature of C-H bonds in acyl chains, hydrogen (δ2H) and carbon (δ13C) stable-isotope values of fatty acids (FA) provide independent information about the origins of fatty acids. Several technical obstacles must be overcome to ensure accurate and reproducible measurements of FA-CSIA can be made. This protocol describes the sample preparation process for successful stable-isotope analyses of fatty acids obtained from environmental and biological samples. Numerous techniques for the preanalytical processing of fatty acid samples are available, and these often have minimal impact on δ values. Here, we provide an in-depth guide detailing our well-established laboratory protocols, ranging from the initial sample preparation, lipid extraction, and transmethylation to the instrumental arrangement, data collection, and analysis.•Protocol from obtaining a sample to standardized fatty acid specific δ2H and δ13C values.•Separate GC analysis procedures for C and H are recommended for optimal performance.
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Affiliation(s)
- Matthias Pilecky
- WasserCluster Biologische Station Lunz, Inter-University Center for Aquatic Ecosystem Research, Dr. Carl-Kupelwieser Promenade 5, 3293 Lunz/See, Austria
- Research lab of Aquatic Ecosystem Research and -Health, Danube University Krems, 3500 Krems, Austria
| | - Leonard I. Wassenaar
- WasserCluster Biologische Station Lunz, Inter-University Center for Aquatic Ecosystem Research, Dr. Carl-Kupelwieser Promenade 5, 3293 Lunz/See, Austria
- Research lab of Aquatic Ecosystem Research and -Health, Danube University Krems, 3500 Krems, Austria
| | - Sami Taipale
- University of Jyväskylä, Department of Biological and Environmental Science, Survontie 9C, Finland
| | - Martin J. Kainz
- WasserCluster Biologische Station Lunz, Inter-University Center for Aquatic Ecosystem Research, Dr. Carl-Kupelwieser Promenade 5, 3293 Lunz/See, Austria
- Research lab of Aquatic Ecosystem Research and -Health, Danube University Krems, 3500 Krems, Austria
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Man X, Huang H, Jiang S, Gu Y, Wang B. The anthropogenic effects on organic matter in sediment core based on Bayesian mixing model: a case study of Daya Bay. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:110191-110203. [PMID: 37783990 DOI: 10.1007/s11356-023-30101-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 09/23/2023] [Indexed: 10/04/2023]
Abstract
Sediment is an important carrier of evidence about environmental evolution which receives huge volumes of organic material originated from both anthropogenic and natural sources. In this study, based on sedimentary chronology, the vertical trends of particle size distribution, total organic carbon (TOC), total nitrogen (TN), and their stable isotopes (δ13C, δ15N) in the sediment core of the nuclear power sea in southwest Daya Bay were analyzed, and the distribution characteristics and contribution ratios of different sources of organic matter in the sedimentary environment over the past 70 years were resolved using a Bayesian mixing model (MixSIAR). TOC, TN, δ13C, and δ15N ranged from 0.89 to 1.56%, 0.09 to 0.2%, - 22.3 to - 20.6‰, and 4.38 to 6.51‰, respectively. The organic matter in the sediment is controlled by a mixture of terrestrial input and marine autochthonous, the proportion of organic matter from terrestrial sources increases, while that from marine sources decreases in the sediment core, which persists from 1960 to 2000, yet organic matter from marine sources still dominates. The first signs of increased primary productivity occurred in 1960, and it was primarily due to agricultural activity. After the 1980s, the rapid increase in population around Daya Bay, the construction of nuclear power plants, the rise of aquaculture, and the quick expansion of industrial bases were all major factors that changed the ecological environment of Daya Bay.
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Affiliation(s)
- Xiangtian Man
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, 511443, China
- Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China
| | - Honghui Huang
- Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China.
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, China.
| | - Shijun Jiang
- College of Oceanography, Hohai University, Nanjing, 210024, China
| | - Yangguang Gu
- Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, China
| | - Boguang Wang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, 511443, China
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Fernández-Corredor E, Francotte L, Martino I, Fernández-Álvarez FÁ, García-Barcelona S, Macías D, Coll M, Ramírez F, Navarro J, Giménez J. Assessing juvenile swordfish (Xiphias gladius) diet as an indicator of marine ecosystem changes in the northwestern Mediterranean Sea. MARINE ENVIRONMENTAL RESEARCH 2023; 192:106190. [PMID: 37820479 DOI: 10.1016/j.marenvres.2023.106190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/31/2023] [Accepted: 09/15/2023] [Indexed: 10/13/2023]
Abstract
To preserve marine biodiversity, we need reliable early warning indicators that inform changes in marine ecosystems. As reliable samplers of mid-trophic level communities, studying the trophodynamics of large pelagic fish can contribute to monitoring these changes. Here, we combined stomach content and stable isotope analyses to reconstruct the diet of juvenile swordfish (Xiphias gladius) in the northwestern Mediterranean Sea, in a time-lapse of almost a decade (2012 and 2020). Overall, our study showed that swordfish fed on a wide range of fish and cephalopod species from both pelagic and demersal habitats. A dietary shift towards increasing consumption of cephalopods and decreasing consumption of Gadiformes had been observed between 2012 and 2020. Stable isotope approaches revealed that gelatinous organisms were also important prey, particularly for smaller-sized swordfish. We underline the importance of combining multiple and complementary approaches to better reconstruct the diet of generalist species. Our findings highlight the generalist and opportunistic diet of Mediterranean swordfish, which makes them good candidates for monitoring changes in the ecosystem.
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Affiliation(s)
| | - Luca Francotte
- Institut de Ciències del Mar (ICM), CSIC, Barcelona, Spain
| | - Ilaria Martino
- Institut de Ciències del Mar (ICM), CSIC, Barcelona, Spain
| | | | | | - David Macías
- Centro Oceanográfico de Málaga (IEO-CSIC), Fuengirola, Spain
| | - Marta Coll
- Institut de Ciències del Mar (ICM), CSIC, Barcelona, Spain; Ecopath International Initiative (EII), Barcelona, Spain
| | | | - Joan Navarro
- Institut de Ciències del Mar (ICM), CSIC, Barcelona, Spain
| | - Joan Giménez
- Institut de Ciències del Mar (ICM), CSIC, Barcelona, Spain
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35
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Gerber R, de Necker L, van Vuren JHJ, Ikenaka Y, Nakayama SMM, Ishizuka M, Wepener V, Smit NJ. A stable isotope analysis of the dietary patterns of the aquatic apex predator, the African tigerfish (Hydrocynus vittatus). JOURNAL OF FISH BIOLOGY 2023; 103:1129-1143. [PMID: 37498144 DOI: 10.1111/jfb.15516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/19/2023] [Accepted: 07/26/2023] [Indexed: 07/28/2023]
Abstract
Stable isotope analyses, specifically δ13 C and δ15 N, are useful tools increasingly used to understand ecosystem function, food web structures, and consumer diets. Although the iconic tigerfish Hydrocynus vittatus is regarded as an apex predator in southern African freshwater systems, little information is available regarding their feeding behavior and how this may change with growth or differ between ecosystems, with most information stemming from stomach content analyses (SCA). The aim of the present study was to address this lack of information through a baseline study of the diet of large and small tigerfish in various lentic and lotic ecosystems in South Africa using stable isotope methods. Fish and various food web components and food sources were collected from two river and two lake ecosystems in South Africa. The δ13 C and δ15 N values for all samples were determined and multivariate analyses and Bayesian analytical techniques applied to determine the feeding ecology of H. vittatus and how this may differ with size and habitat type. Analyses revealed a substantial difference in the type and abundance of food sources contributing to the diet of H. vittatus between ecosystems, most prominently between the lotic systems, where less dietary specialization was observed, and lentic systems where more specialization was observed. Furthermore, there was a distinct difference in diet between small and large tigerfish, especially in the lotic system, indicating an ontogenetic diet shift as tigerfish grow and further supporting previous SCA studies. This is the first study of its kind on the African continent for H. vittatus and the findings illustrate the value of stable isotope analysis in providing in-depth information into the feeding ecology of consumers and how this may differ between size classes and habitat types.
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Grants
- 127549 Department of Science and Innovation Professional Development Programme
- 22KK0163 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- 17KK0009 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- 18KK028708 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- 17K2003807 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- 18H0413208 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- 20K20633 Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan
- 105979 National Research Foundation of South Africa
- 85505 National Research Foundation of South Africa
- 105122 National Research Foundation of South Africa
- K5-1922 Water Research Commission of South Africa
- K5-2185 Water Research Commission of South Africa
- JPMJSA1501 JST/JICA SATREPS (Science and Technology Research Partnership for Sustainable Development
- JPMJAS2001 aXis (Accelerating Social Implementation for SDGs Achievement
- PJ36210002 JST AJ-CORE
- JSPS CORE to CORE program
- Hokkaido University SOUSEI Tokutei Research
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Affiliation(s)
- Ruan Gerber
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Lizaan de Necker
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
- South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda, South Africa
| | - Johan H J van Vuren
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Yoshinori Ikenaka
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- Translational Research Unit, Veterinary Teaching hospital, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- One Health Research Center, Hokkaido University, Sapporo, Japan
| | - Shouta M M Nakayama
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Mayumi Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Victor Wepener
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Nico J Smit
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
- South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda, South Africa
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Holthuijzen WA, Flint EN, Green SJ, Plissner JH, Simberloff D, Sweeney D, Wolf CA, Jones HP. An invasive appetite: Combining molecular and stable isotope analyses to reveal the diet of introduced house mice (Mus musculus) on a small, subtropical island. PLoS One 2023; 18:e0293092. [PMID: 37856477 PMCID: PMC10586637 DOI: 10.1371/journal.pone.0293092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 10/04/2023] [Indexed: 10/21/2023] Open
Abstract
House mice (Mus musculus) pose a conservation threat on islands, where they adversely affect native species' distributions, densities, and persistence. On Sand Island of Kuaihelani, mice recently began to depredate nesting adult mōlī (Laysan Albatross, Phoebastria immutabilis). Efforts are underway to eradicate mice from Sand Island, but knowledge of mouse diet is needed to predict ecosystem response and recovery following mouse removal. We used next-generation sequencing to identify what mice eat on Sand Island, followed by stable isotope analysis to estimate the proportions contributed by taxa to mouse diet. We collected paired fecal and hair samples from 318 mice between April 2018 to May 2019; mice were trapped approximately every eight weeks among four distinct habitat types to provide insight into temporal and spatial variation. Sand Island's mice mainly consume arthropods, with nearly equal (but substantially smaller) contributions of C3 plants, C4 plants, and mōlī. Although seabird tissue is a small portion of mouse diet, mice consume many detrital-feeding arthropods in and around seabird carcasses, such as isopods, flesh flies, ants, and cockroaches. Additionally, most arthropods and plants eaten by mice are non-native. Mouse diet composition differs among habitat types but changes minimally throughout the year, indicating that mice are not necessarily limited by food source availability or accessibility. Eradication of house mice may benefit seabirds on Sand Island (by removing a terrestrial, non-native predator), but it is unclear how arthropod and plant communities may respond and change. Non-native and invasive arthropods and plants previously consumed (and possibly suppressed) by mice may be released post-eradication, which could prevent recovery of native taxa. Comprehensive knowledge of target species' diet is a critical component of eradication planning. Dietary information should be used both to identify and to monitor which taxa may respond most strongly to invasive species removal and to assess if proactive, pre-eradication management activities are warranted.
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Affiliation(s)
- Wieteke A. Holthuijzen
- Department of Ecology & Evolutionary Biology, University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Elizabeth N. Flint
- Marine National Monuments of the Pacific, U.S. Fish and Wildlife Service, Honolulu, Hawaiʻi, United States of America
| | - Stefan J. Green
- Genomics and Microbiome Core Facility, Rush University Medical Center, Chicago, Illinois, United States of America
| | - Jonathan H. Plissner
- Midway Atoll National Wildlife Refuge, U.S. Fish and Wildlife Service, Waipahu, Hawaiʻi, United States of America
| | - Daniel Simberloff
- Department of Ecology & Evolutionary Biology, University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Dagmar Sweeney
- Institute for Health Research & Policy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Coral A. Wolf
- Island Conservation, Santa Cruz, California, United States of America
| | - Holly P. Jones
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, United States of America
- Institute for the Study of the Environment, Sustainability, and Energy, Northern Illinois University, DeKalb, Illinois, United States of America
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Xu Z, Luo K, Lu Q, Shang L, Tian J, Lu Z, Li Q, Chen Z, Qiu G. The mercury flow through a terrestrial songbird food chain in subtropical pine forest: Elucidated by Bayesian isotope mixing model and stable mercury isotopes. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132263. [PMID: 37573826 DOI: 10.1016/j.jhazmat.2023.132263] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 07/31/2023] [Accepted: 08/08/2023] [Indexed: 08/15/2023]
Abstract
In order to comprehend the transfer of inorganic mercury (IHg) and methylmercury (MeHg) within food chains in terrestrial pine forests, we collected samples of Great Tit nestlings, common invertebrates, plants, and soil in a subtropical pine forest and used Bayesian isotope mixing model analysis, Hg daily intake, and stable Hg isotopes to elucidate the flow of MeHg and IHg in these food chains. Results indicate that caterpillars and cockroaches are the predominant prey items for nestlings, accounting for a combined contribution of 81.5%. Furthermore, caterpillars, cockroaches, and spiders were found to contribute the most (∼80%) of both IHg and MeHg that dietary accumulated in nestlings. The provisoned invertebrates tend to supply more IHg and diluting the proportion of MeHg as total Hg (MeHg%). Notably, nestling feathers displayed the highest Δ199Hg values but a relatively lower MeHg%, suggesting an imbalanced incorporation of Hg from maternal transfer and dietary accumulation during the nestling stage. This study highlights the efficacy of nestlings as indicators for identifying Hg sources and transfers in avian species and food chains. However, caution must be exercised when using Hg isotope compositions in growing feathers, and the contribution of maternally transferred Hg should not be ignored.
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Affiliation(s)
- Zhidong Xu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Kang Luo
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences, Jingdong 676200, China
| | - Qinhui Lu
- The Key Laboratory of Environment Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang 550025, China
| | - Lihai Shang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Jing Tian
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Zhiyun Lu
- Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences, Jingdong 676200, China
| | - Qiuhua Li
- Guizhou Key Laboratory for Mountainous Environmental Information and Ecological Protection, Guizhou Normal University, Guiyang 550001, China
| | - Zhuo Chen
- School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550001, China
| | - Guangle Qiu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
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Berthelot F, Unnsteinsdóttir ER, Carbonell Ellgutter JA, Ehrich D. Long-term responses of Icelandic Arctic foxes to changes in marine and terrestrial ecosystems. PLoS One 2023; 18:e0282128. [PMID: 37792685 PMCID: PMC10550166 DOI: 10.1371/journal.pone.0282128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 09/03/2023] [Indexed: 10/06/2023] Open
Abstract
The long-term dynamics of predator populations may be driven by fluctuations in resource availability and reflect ecosystem changes such as those induced by climate change. The Icelandic Arctic fox (Vulpes lagopus) population has known major fluctuations in size since the 1950s. Using stable isotopes analysis of bone collagen over a long-time series (1979-2018), we aimed at identifying the main resources used by Icelandic Arctic foxes during periods of growth and decline to assess if the variations in their population size are linked to fluctuations in the availability of resources. We hypothesized that (1) the decline in Seabird abundance was responsible for the decrease in the fox population; and (2) that the growth in the fox population combined to fluctuations in main resources would lead to an increase in intra-specific competition, ultimately leading to variations in their isotopic niches at the population scale. The isotopic composition of Arctic fox bones differed clearly between inland and coast. Stable isotopes mixing models suggested that marine resources and rock ptarmigans were the most important food source and highlighted a rather stable diet in coastal habitats compared to inland habitats where more fluctuations in dietary composition were observed. Coastal foxes had a broader niche than inland foxes, and there was more variation in niche size in the inland habitat. Our results tend to confirm that a general decline in seabird populations drove the decline in Arctic foxes, especially in coastal habitats. For the inland foxes, our results suggest that the lack of marine resources might have led to an increased use of ptarmigans especially during the most recent period.
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Affiliation(s)
- Fanny Berthelot
- Department of Arctic and Marine Biology, UiT -The Arctic University of Norway, Tromsø, Norway
| | | | | | - Dorothee Ehrich
- Department of Arctic and Marine Biology, UiT -The Arctic University of Norway, Tromsø, Norway
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Fanelli E, Da Ros Z, Menicucci S, Malavolti S, Biagiotti I, Canduci G, De Felice A, Leonori I. The pelagic food web of the Western Adriatic Sea: a focus on the role of small pelagics. Sci Rep 2023; 13:14554. [PMID: 37666876 PMCID: PMC10477188 DOI: 10.1038/s41598-023-40665-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 08/16/2023] [Indexed: 09/06/2023] Open
Abstract
The Adriatic Sea is one of the largest areas of occurrence of shared small pelagic stocks and the most fished area of the Mediterranean Sea, which is in turn one of the most exploited basins of the world. The variations in the stable isotope contents (δ15N and δ13C) were determined for three small pelagic fishes (i.e., Engraulis encrasicolus, Sardina pilchardus, and Sprattus sprattus, respectively known as anchovies, sardines and sprats) collected across the western side of the basin. Our data allowed to determine the width and features of their trophic niches, to assess potential overlap or resource partitioning among them, and likely anticipate species adaptation to future climate change scenarios. Moreover, variations in stable isotope contents were correlated to both resource availability (i.e., mesozooplankton) and environmental variables. The high productivity and in turn the high resource availability of the basin, especially in the northern part, resulted in favor of the resource partitioning that occurs in each sub-area of the Adriatic Sea among the three species. Medium-sized specimens of the three species mostly fed on small zooplankton, while adult sprats relied on large copepods and those of sardines and anchovies also consumed large portion of phytoplankton, confirming the high trophic plasticity of these two dominants small pelagic species. However, considering that anchovies have the greatest degree of trophic diversity compared with the other two species, they could be the most adapted to changing feeding conditions. The increase in sea temperatures that are reducing primary production and in turn zooplankton abundances, coupled with even more frequent extreme meteorologic events could exacerbate the competition for trophic resources among pelagic mesopredators, and could lead to more notable stocks' fluctuations and unpredictable wasp-waist effects.
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Affiliation(s)
- E Fanelli
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131, Ancona, Italy.
- Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, Italy.
- Institute for Marine Biological Resources and Biotechnologies (IRBIM), National Research Council (CNR), Largo Fiera Della Pesca, 60125, Ancona, Italy.
| | - Z Da Ros
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131, Ancona, Italy
| | - S Menicucci
- Institute for Marine Biological Resources and Biotechnologies (IRBIM), National Research Council (CNR), Largo Fiera Della Pesca, 60125, Ancona, Italy
- Alma Mater Studiorum, Università di Bologna, Via Zamboni, 33, 40126, Bologna, Italy
| | - S Malavolti
- Institute for Marine Biological Resources and Biotechnologies (IRBIM), National Research Council (CNR), Largo Fiera Della Pesca, 60125, Ancona, Italy
| | - I Biagiotti
- Institute for Marine Biological Resources and Biotechnologies (IRBIM), National Research Council (CNR), Largo Fiera Della Pesca, 60125, Ancona, Italy
| | - G Canduci
- Institute for Marine Biological Resources and Biotechnologies (IRBIM), National Research Council (CNR), Largo Fiera Della Pesca, 60125, Ancona, Italy
| | - A De Felice
- Institute for Marine Biological Resources and Biotechnologies (IRBIM), National Research Council (CNR), Largo Fiera Della Pesca, 60125, Ancona, Italy
| | - I Leonori
- Institute for Marine Biological Resources and Biotechnologies (IRBIM), National Research Council (CNR), Largo Fiera Della Pesca, 60125, Ancona, Italy
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Bedard B, Hickey B, Chételat J, Mennigen JA. Variation in habitat use and its consequences for mercury exposure in two Eastern Ontario bat species, Myotis lucifugus and Eptesicus fuscus. ECOTOXICOLOGY (LONDON, ENGLAND) 2023; 32:845-857. [PMID: 37612563 DOI: 10.1007/s10646-023-02693-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/11/2023] [Indexed: 08/25/2023]
Abstract
The St. Lawrence River in Eastern Ontario, Canada, has been a designated an area of concern due to past industrial contamination of sediment in some areas and transport of mercury from tributaries. Previous research using bats as sentinel species identified elevated concentrations of total mercury (THg) in fur of local bats and species-specific variation between little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus). Here, we investigated the mercury exposure pathways for these two species by testing the hypothesis that diet variation, particularly the reliance on aquatic over terrestrial insects, is a determinant of local bat mercury concentrations. We analyzed THg concentration and stable isotope ratios of δ15N and δ13C in fur of little and big brown bats, and in aquatic and terrestrial insects. Big brown bats, especially males, accumulated significantly higher THg concentrations in their fur compared to little brown bats. However, this difference was not related to diet because big brown bats consumed terrestrial insects, which were lower in mercury than aquatic insects, the primary prey for little brown bats. We also evaluated whether fur THg concentrations translate into molecular changes in tissues linked to (methyl)mercury toxicity by quantifying tissue changes in global DNA methylation and mitochondrial DNA abundance. No significant changes in DNA molecular markers were observed in relation to fur THg concentration, suggesting mercury exposure to local bats did not impact molecular level changes at the DNA level. Higher mercury in bats was not associated with local aquatic contamination or genotoxicity in this study area.
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Affiliation(s)
- Bailey Bedard
- Department of Biology, University of Ottawa, Ottawa, ON, K1N6A5, Canada
- River Institute, Cornwall, ON, K6H4Z1, Canada
| | | | - John Chételat
- National Wildlife Research Centre, Environment and Climate Change Canada, Ottawa, ON, K1A0H3, Canada
| | - Jan A Mennigen
- Department of Biology, University of Ottawa, Ottawa, ON, K1N6A5, Canada.
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41
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Condini MV, Garcia AM, Bastos RF, Vollrath SR, Barbosa EF, Oliveira RL, Almeida LL, Hostim-Silva M. Hydroclimatic influence on the trophic ecology of Atlantic goliath grouper juveniles (Epinephelus itajara) in a tropical estuary using non-lethal methodologies. MARINE ENVIRONMENTAL RESEARCH 2023; 190:106103. [PMID: 37473597 DOI: 10.1016/j.marenvres.2023.106103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/04/2023] [Accepted: 07/12/2023] [Indexed: 07/22/2023]
Abstract
The Atlantic goliath grouper Epinephelus itajara is the largest species of groupers in the Atlantic Ocean, reaching over 2 m total length and 400 kg. It has an ontogenetic migration, with adults using nearshore and offshore marine areas and juveniles inhabiting estuarine/mangrove areas. Despite of its high ecological relevance and classification as a threatened species for several decades in the IUCN red lists, critical phases of its life cycle, like juveniles inhabiting estuaries, are still poorly investigated. In this study, we evaluated if hydroclimatic changes may affect the trophic ecology of juveniles in a tropical estuary. We described their diet composition, isotopic niche area, food assimilation, and trophic position of juveniles across seasons using two non-lethal techniques: stomach content analysis using a stomach flushing procedure and stable isotope analysis using a dermal biopsy. A total of 87 individuals with TL ranging from 38 to 331 mm had their stomachs analyzed, of which 31 had food content. We identified 11 prey items, shrimp being the most abundant prey group (IRI% = 88.4), followed by fish (6.6), blue crab (2.8), and crab (2.2). A total of 93 specimens had their muscle's carbon (δ13C) and nitrogen (δ15N) stable isotope ratios analyzed (38-332 mm TL). Average δ13C values showed statistically significant changes across seasons, but no significant changes were observed for δ15N. As initially predicted, isotopic niche size of juveniles changed consistently along the entire hydroclimatic cycle, reaching its peak at the end of the wet season. We also observed changes in the proportion of prey assimilation by juveniles between seasons. Shrimp (92.1%) was the most assimilated prey group during the late dry season, whereas tidal crabs (36.7%), blue crab (27.8%), and shrimp (25.1%) were the most important in the late wet season. Average trophic position of juveniles remained similar across wet (3.32 ± 0.10) and dry (3.23 ± 0.11) seasons. These findings provide important information to help decision makers to promote more efficient management and conservation legislations to protect early life stages of the Atlantic goliath grouper in tropical estuaries.
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Affiliation(s)
- Mario V Condini
- Laboratório de Ecologia de Peixes Marinhos - LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, km 60 - Litorâneo, CEP: 29932-540, São Mateus, ES, Brazil; Programa de Pós-Graduação em Oceanografia Ambiental (PPGOAM), Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil.
| | - Alexandre M Garcia
- Laboratório de Ictiologia, Instituto de Oceanografia, Universidade Federal do Rio Grande, Av. Itália Km 8, Carreiros. 96.201-900, Rio Grande, RS, Brazil
| | - Rodrigo F Bastos
- Laboratório de Ecologia de Peixes Marinhos - LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, km 60 - Litorâneo, CEP: 29932-540, São Mateus, ES, Brazil; Programa de Pós-Graduação em Oceanografia Ambiental (PPGOAM), Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil
| | - Sabrina R Vollrath
- Laboratório de Ictiologia, Instituto de Oceanografia, Universidade Federal do Rio Grande, Av. Itália Km 8, Carreiros. 96.201-900, Rio Grande, RS, Brazil
| | - Ester F Barbosa
- Laboratório de Ecologia de Peixes Marinhos - LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, km 60 - Litorâneo, CEP: 29932-540, São Mateus, ES, Brazil
| | - Rafael L Oliveira
- Laboratório de Ecologia de Peixes Marinhos - LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, km 60 - Litorâneo, CEP: 29932-540, São Mateus, ES, Brazil; Programa de Pós-Graduação em Ciências Biológicas (Biologia Animal - PPGBAN), Departamento de Ciências Biológicas, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil
| | - Lorena L Almeida
- Laboratório de Ecologia de Peixes Marinhos - LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, km 60 - Litorâneo, CEP: 29932-540, São Mateus, ES, Brazil; Programa de Pós-Graduação em Ciências Biológicas (Biologia Animal - PPGBAN), Departamento de Ciências Biológicas, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil
| | - Maurício Hostim-Silva
- Laboratório de Ecologia de Peixes Marinhos - LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, km 60 - Litorâneo, CEP: 29932-540, São Mateus, ES, Brazil; Programa de Pós-Graduação em Oceanografia Ambiental (PPGOAM), Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil; Programa de Pós-Graduação em Ciências Biológicas (Biologia Animal - PPGBAN), Departamento de Ciências Biológicas, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil; Instituto Meros do Brasil, Rua Benjamin Cosntant 67, Conj. 1104, CEP: 80060-020, Curitiba, PR, Brazil
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Baumann C, Hussain ST, Roblíčková M, Riede F, Mannino MA, Bocherens H. Evidence for hunter-gatherer impacts on raven diet and ecology in the Gravettian of Southern Moravia. Nat Ecol Evol 2023; 7:1302-1314. [PMID: 37349568 DOI: 10.1038/s41559-023-02107-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 05/25/2023] [Indexed: 06/24/2023]
Abstract
The earlier Gravettian of Southern Moravia-the Pavlovian-is notable for the many raven bones (Corvus corax) documented in its faunal assemblages. On the basis of the rich zooarchaeological and settlement data from the Pavlovian, previous work suggested that common ravens were attracted by human domestic activities and subsequently captured by Pavlovian people, presumably for feathers and perhaps food. Here, we report independent δ15N, δ13C and δ34S stable isotope data obtained from 12 adult ravens from the Pavlovian key sites of Předmostí I, Pavlov I and Dolní Věstonice I to test this idea. We show that Pavlovian ravens regularly fed on larger herbivores and especially mammoths, aligning in feeding preferences with contemporaneous Gravettian foragers. We argue that opportunistic-generalist ravens were encouraged by human settlement and carcass provisioning. Our data may thus provide surprisingly early evidence for incipient synanthropism among Palaeolithic ravens. We suggest that anthropogenic manipulation of carrion supply dynamics furnished unique contexts for the emergence of human-oriented animal behaviours, in turn promoting novel human foraging opportunities-dynamics which are therefore important for understanding early hunter-gatherer ecosystem impacts.
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Affiliation(s)
- Chris Baumann
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
- Biogeology Research Group, Department of Geosciences, University of Tübingen, Tübingen, Germany
| | - Shumon T Hussain
- Department of Archaeology and Heritage Studies, Aarhus University, Aarhus, Denmark.
- BIOCHANGE - Center for Biodiversity Dynamics in a Changing World, Department of Biology, Aarhus University, Aarhus, Denmark.
- Center for Environmental Humanities (CEH), School of Culture and Society, Aarhus University, Aarhus, Denmark.
| | | | - Felix Riede
- Department of Archaeology and Heritage Studies, Aarhus University, Aarhus, Denmark
- BIOCHANGE - Center for Biodiversity Dynamics in a Changing World, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Marcello A Mannino
- Department of Archaeology and Heritage Studies, Aarhus University, Aarhus, Denmark
| | - Hervé Bocherens
- Biogeology Research Group, Department of Geosciences, University of Tübingen, Tübingen, Germany
- Senckenberg Centre for Human Evolution and Palaeoenvironment, University of Tübingen, Tübingen, Germany
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Ishii Y, Nakagawa M, Matsuzaki SIS, Jo J, Hayashi S. Contrasting radiocesium transfer in the river and lake food webs: Importance of trophic level and food source. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2023; 263:107184. [PMID: 37119681 DOI: 10.1016/j.jenvrad.2023.107184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/09/2023] [Accepted: 04/14/2023] [Indexed: 05/06/2023]
Abstract
Radiocesium (137Cs) contamination of the freshwater ecosystems adjacent to the Fukushima Daiichi Nuclear Power Plant (FDNPP) in Japan has persisted long after the accident that occurred at the facility in March 2011. It is necessary to elucidate the dynamics of 137Cs in various aquatic ecosystems to predict 137Cs concentrations in fish and manage freshwater fisheries in the vicinity of FDNPP. To these ends, we applied stable isotope analysis to evaluate changes in 137Cs levels through trophic positions and the relative importance of the 137Cs sources at the trophic bases of two rivers and two lakes in Fukushima. The δ15N analyses disclosed that 137Cs decreases from primary producers to fish consumers in the river food web and 137Cs increases among fish consumers with increasing trophic position in the lake food web. The δ13C analysis revealed that autochthonous 137Cs contributed to fish contamination. The periphyton-dependent and zooplankton-dependent fish had comparatively higher 137Cs concentrations in the rivers and lakes, respectively. Cesium-137 supply from the pelagic food web was observed to contribute to greater 137Cs levels in the fish consumers inhabiting the lakes. The results of this study show that stable isotope analysis may help clarify 137Cs dynamics in freshwater food webs and identify the important 137Cs sources in the food web. Identifying important 137Cs sources and trophic transfers depending on the ecosystem help guide regulatory and management frameworks to establish profitability of the food fish stocks there and maintain food security.
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Affiliation(s)
- Yumiko Ishii
- Environmental Impact Assessment Section, Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, 10-2 Fukasaku, Miharu Town, Tamura County, Fukushima Prefecture, 963-7700, Japan.
| | - Megumi Nakagawa
- Biodiversity Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Shin-Ichiro S Matsuzaki
- Biodiversity Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Jaeick Jo
- Environmental Impact Assessment Section, Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, 10-2 Fukasaku, Miharu Town, Tamura County, Fukushima Prefecture, 963-7700, Japan
| | - Seiji Hayashi
- Environmental Impact Assessment Section, Fukushima Regional Collaborative Research Center, National Institute for Environmental Studies, 10-2 Fukasaku, Miharu Town, Tamura County, Fukushima Prefecture, 963-7700, Japan
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Jiang Y, Zeng Y, Lu R, Zhang Y, Long L, Zheng X, Luo X, Mai B. Application of amino acids nitrogen stable isotopic analysis in bioaccumulation studies of pollutants: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 879:163012. [PMID: 36965734 DOI: 10.1016/j.scitotenv.2023.163012] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/17/2023] [Accepted: 03/18/2023] [Indexed: 05/17/2023]
Abstract
Accurately quantifying trophic positions (TP) to describe food web structure is an important element in studying pollutant bioaccumulation. In recent years, compound-specific nitrogen isotopic analysis of amino acids (AAs-N-CSIA) has been progressively applied as a potentially reliable tool for quantifying TP, facilitating a better understanding of pollutant food web transfer. Therefore, this review provides an overview of the analytical procedures, applications, and limitations of AAs-N-CSIA in pollutant (halogenated organic pollutants (HOPs) and heavy metals) bioaccumulation studies. We first summarize studies on the analytical techniques of AAs-N-CSIA, including derivatization, instrumental analysis, and data processing methods. The N-pivaloyl-i-propyl-amino acid ester method is a more suitable AAs derivatization method for quantifying TP. The AAs-N-CSIA application in pollutant bioaccumulation studies (e.g., Hg, MeHg, and HOPs) is discussed, and its application in conjunction with various techniques (e.g., spatial analysis, food source analysis, and compound tracking techniques, etc.) to research the influence of pollutant levels on organisms is summarized. Finally, the limitations of AAs-N-CSIA in pollutant bioaccumulation studies are discussed, including the use of single empirical values of βglu/phe and TDFglu/phe that result in large errors in TP quantification. The weighted βglu/phe and the multi-TDFglu/phe models are still challenging to solve for accurate TP quantification of omnivores; however, factors affecting the variation of βglu/phe and TDFglu/phe are unclear, especially the effect of pollutant bioaccumulation in organisms on internal AA metabolic processes.
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Affiliation(s)
- Yiye Jiang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanhong Zeng
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China.
| | - Ruifeng Lu
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanting Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ling Long
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaobo Zheng
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Xiaojun Luo
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China
| | - Bixian Mai
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China
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Matej-Łukowicz K, Wojciechowska E, Kolerski T, Nawrot N, Kuliński K, Winogradow A. Sources of contamination in sediments of retention tanks and the influence of precipitation type on the size of pollution load. Sci Rep 2023; 13:8884. [PMID: 37264055 DOI: 10.1038/s41598-023-35568-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 05/20/2023] [Indexed: 06/03/2023] Open
Abstract
Densification of cities and urban population contributes to increased runoff and suspended solids and alteration of the urban water cycle. Nowadays, Blue-Green Infrastructure is promoted to increase a city's resilience to floods; however, stormwater drainage systems, supported with retention tanks are still important in protecting urban areas against floods. Sediment accumulation in stormwater infrastructure relates to an issue of pollutants such as heavy metals, nutrients etc. Research on the origin of the pollutants associated with the suspension and ultimately sediment accumulated in sewage can bring new insights about processes in urban catchment areas. This is the first study, which is focused on the analysis of stable carbon and nitrogen isotopes in bottom sediments collected from municipal retention tanks to verify the origin of the deposited pollutants immediately after pluvial floods. The research was additionally extended with water quality analyzes immediately after three types of weather: a dry period, typical precipitation (< 30 mm) and torrential rainfalls (2 events with daily precipitation over 30 mm which caused pluvial flooding of the city area). Analyses of sediments indicated that the main source of carbon and nitrogen in the bottom of the retention tanks had been brought with stormwater runoff from the city area. Organic nitrogen fertilizers appeared to be the main source of nitrogen, while the sources of organic carbon were mixed: C3 land plants, wood, and oil. Additionally, it was found that torrential rainfall caused a 23-fold increase of N-NO3 concentration, a sevenfold increase of P-PO4 concentration, and an over fivefold increase of concentration of organic matter, in comparison to typical precipitation.
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Affiliation(s)
- Karolina Matej-Łukowicz
- Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Narutowicza 11/12, 80-233, Gdańsk, Poland.
| | - Ewa Wojciechowska
- Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Narutowicza 11/12, 80-233, Gdańsk, Poland
| | - Tomasz Kolerski
- Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Narutowicza 11/12, 80-233, Gdańsk, Poland
| | - Nicole Nawrot
- Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, Narutowicza 11/12, 80-233, Gdańsk, Poland
| | - Karol Kuliński
- Institute of Oceanology of the Polish Academy of Sciences, Powstańców Warszawy 55, 81-712, Sopot, Poland
| | - Aleksandra Winogradow
- Institute of Oceanology of the Polish Academy of Sciences, Powstańców Warszawy 55, 81-712, Sopot, Poland
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46
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Ziegler AF, Bluhm BA, Renaud PE, Jørgensen LL. Isotopic turnover in polar cod (Boreogadus saida) muscle determined through a controlled feeding experiment. JOURNAL OF FISH BIOLOGY 2023; 102:1442-1454. [PMID: 36999199 DOI: 10.1111/jfb.15389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 03/29/2023] [Indexed: 06/09/2023]
Abstract
Polar cod (Boreogadus saida) is an important trophic link within Arctic marine food webs and is likely to experience diet shifts in response to climate change. One important tool for assessing organism diet is bulk stable isotope analysis. However, key parameters necessary for interpreting the temporal context of stable isotope values are lacking, especially for Arctic species. This study provides the first experimental determination of isotopic turnover (as half-life) and trophic discrimination factors (TDFs) of both δ13 C and δ15 N in adult polar cod muscle. Using a diet enriched in both 13 C and 15 N, we measured isotopic turnover times of 61 and 49 days for δ13 C and δ15 N, respectively, with metabolism accounting for >94% of the total turnover. These half-life estimates are valid for adult polar cod (>3 years) experiencing little somatic growth. We measured TDFs in our control of 2.6‰ and 3.9‰ for δ13 C and δ15 N, respectively, and we conclude that applying the commonly used TDF of ~1‰ for δ13 C for adult polar cod may lead to misrepresentation of dietary carbon source, while the use of 3.8‰ for δ15 N is appropriate. Based on these results, we recommend that studies investigating seasonal shifts in the diet of adult polar cod sample at temporal intervals of at least 60 days to account for isotopic turnover in polar cod muscle. Although isotopic equilibrium was reached by the fish in this study, it was at substantially lower isotope values than the diet. Additionally, the use of highly enriched algae in the experimental feed caused very high variability in diet isotope values which precluded accurate calculation of TDFs from the enriched fish. As a result of the challenges faced in this study, we discourage the use of highly enriched diets for similar experiments and provide recommendations to guide the design of future isotopic turnover experiments.
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Affiliation(s)
- Amanda Fern Ziegler
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø, Norway
- Institute of Marine Research, Fram Centre, Tromsø, Norway
| | - Bodil A Bluhm
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø, Norway
| | - Paul E Renaud
- Akvaplan-niva, Fram Centre for Climate and the Environment, Tromsø, Norway
- University Centre in Svalbard, Longyearbyen, Norway
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García-Vázquez A, Bălășescu A, Vasile G, Golea M, Radu V, Opriș V, Ignat T, Culea M, Covătaru C, Sava G, Lazăr C. Unravelling the resilience of the KGK VI population from the Gumelnița site (Romania) through stable isotopes. Sci Rep 2023; 13:8499. [PMID: 37231015 DOI: 10.1038/s41598-023-35129-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 05/12/2023] [Indexed: 05/27/2023] Open
Abstract
The Gumelnița site belongs to the Kodjadermen-Gumelnița-Karanovo VI (KGK VI) communities (c. 4700-3900 cal BC) and comprises the tell-type settlement and its corresponding cemetery. This paper reconstructs the diet and lifeways of the Chalcolithic people in the northeastern Balkans using archaeological remains found at the Gumelnița site (Romania). A multi-bioarchaeological investigation (archaeobotany, zooarchaeology, anthropology) was conducted on vegetal, animal, and human remains, alongside radiocarbon dating and stable isotope analyses (δ13C, δ15N) of humans (n = 33), mammals (n = 38), reptiles (n = 3), fishes (n = 8), freshwater mussels shells (n = 18), and plants (n = 24). According to the results of δ13C and δ15N values and FRUITS, the inhabitants of Gumelnița had a diet based on crops and using natural resources, such as fish, freshwater molluscs and game. Although domestic fauna was occasionally exploited for meat, it had a role in providing secondary products. Crops were heavily manured, and chaff and other crop waste may have been necessary fodder for cattle and sheep. Dogs and pigs fed on human waste, although the diet of the latter is more similar to that of wild boars. Foxes had a diet close to dogs, which may indicate synanthropic behaviour. Radiocarbon dates were calibrated with the percentage of freshwater resources obtained by FRUITS. As a result, the corrected dates for the freshwater reservoir effect (FRE) have a delay of an average of 147 years. According to our data, this agrarian community developed a subsistence strategy under the pressure of some climatic changes that started after 4300 cal BC, corresponding to KGK VI rapid collapse/decline episode tracked recently (that begins around 4350 cal BC). This matching of our data in the two models (climatic and chrono-demographic) allowed us to capture the economic strategies that led to the resilience of those people more than other contemporary KGK VI communities.
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Affiliation(s)
- Ana García-Vázquez
- ArchaeoSciences Platform, Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania.
| | - Adrian Bălășescu
- ArchaeoSciences Platform, Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania
- "Vasile Pârvan" Institute of Archaeology, Romanian Academy, Bucharest, Romania
| | - Gabriel Vasile
- "Vasile Pârvan" Institute of Archaeology, Romanian Academy, Bucharest, Romania
| | - Mihaela Golea
- "Vasile Pârvan" Institute of Archaeology, Romanian Academy, Bucharest, Romania
| | - Valentin Radu
- ArchaeoSciences Platform, Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania
- National Museum of Romanian History, Bucharest, Romania
| | - Vasile Opriș
- ArchaeoSciences Platform, Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania
- Bucharest Municipality Museum, Bucharest, Romania
| | - Theodor Ignat
- ArchaeoSciences Platform, Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania
- Bucharest Municipality Museum, Bucharest, Romania
| | - Mihaela Culea
- "Francisc J. Rainer" Institute of Anthropology, Romanian Academy, Bucharest, Romania
| | - Cristina Covătaru
- ArchaeoSciences Platform, Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania
| | - Gabriela Sava
- Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, Măgurele, Romania
| | - Cătălin Lazăr
- ArchaeoSciences Platform, Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania.
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Kolbenschlag S, Bollinger E, Gerstle V, Brühl CA, Entling MH, Schulz R, Bundschuh M. Impact across ecosystem boundaries - Does Bti application change quality and composition of the diet of riparian spiders? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 873:162351. [PMID: 36822417 DOI: 10.1016/j.scitotenv.2023.162351] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/16/2023] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
Emerging aquatic insects link aquatic and adjacent terrestrial food webs by subsidizing terrestrial predators with high-quality prey. One of the main constituents of aquatic subsidy, the non-biting midges (Chironomidae), showed altered emergence dynamics in response to the mosquito control agent Bacillus thuringiensis var. israelensis (Bti). As riparian spiders depend on aquatic subsidy, they may be affected by such changes in prey availability. Thus, we conducted a field study in twelve floodplain pond mesocosms (FPMs), six were treated with Bti (2.88 × 109 ITU/ha, VectoBac WDG) three times, to investigate if the Bti-induced shift in chironomid emergence dynamics is reflected in their nutritional value and in the diet of riparian spiders. We measured the content of proteins, lipids, glycogen, and carbohydrates in emerged Chironomidae, and determined the stable isotope ratios of female Tetragnatha extensa, a web-building spider living in the riparian vegetation of the FPMs. We analysed the proportion of aquatic prey in spiders' diet, niche size, and trophic position. While the content of nutrients and thus the prey quality was not significantly altered by Bti, effects on the spiders' diet were observed. The trophic position of T. extensa from Bti-treated FPMs was lower compared to the control while the aquatic proportion was only minimally reduced. We assume that spiders fed more on terrestrial prey but also on other aquatic organisms such as Baetidae, whose emergence was unaffected by Bti. In contrast to the partly predaceous Chironomidae, consumption of aquatic and terrestrial primary consumers potentially explains the observed lower trophic position of spiders from Bti-treated FPMs. As prey organisms vary in their quality the suggested dietary shift could transfer previously observed effects of Bti to riparian spiders conceivably affecting their populations. Our results further support that anthropogenic stressors in aquatic ecosystems may translate to terrestrial predators through aquatic subsidy.
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Affiliation(s)
- Sara Kolbenschlag
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany
| | - Eric Bollinger
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany
| | - Verena Gerstle
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany
| | - Carsten A Brühl
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany
| | - Martin H Entling
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany
| | - Ralf Schulz
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany; Eußerthal Ecosystem Research Station, RPTU Kaiserslautern-Landau, Birkenthalstr. 13, D-76857 Eußerthal, Germany
| | - Mirco Bundschuh
- iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstr. 7, D-76829 Landau, Germany; Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, SWE-75007 Uppsala, Sweden.
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Mofu L, Dalu T, Wasserman RJ, Woodford DJ, Weyl OLF. Trophic ecology of co-occurring fishes in the Sundays River Valley irrigation ponds, assessed using stable isotope and gut content analyses. JOURNAL OF FISH BIOLOGY 2023; 102:1191-1205. [PMID: 36856200 DOI: 10.1111/jfb.15360] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 02/17/2023] [Indexed: 05/13/2023]
Abstract
The analysis of food web structures has increased the understanding of the dynamics of organisms belonging to different trophic levels. In this study, the diet of two native species, Glossogobius callidus and Gilchristella aestuaria, was assessed in the presence of two non-native species, Oreochromis mossambicus and Gambusia affinis, in irrigation ponds, Eastern Cape Province, South Africa. The proportion of dietary items consumed and assimilated by the four fish species were inferred from gut contents and carbon and nitrogen stable isotope analysis. Stable isotope analysis revealed that both G. affinis and O. mossambicus had a larger isotopic niche size than G. callidus and G. aestuaria. Although G. callidus fed on benthic resources and G. aestuaria fed on phytoplankton, gut content analysis showed that G. callidus, O. mossambicus and G. affinis fed predominantly on benthic resources, whereas G. aestuaria fed mainly on plankton resources. Considerable niche overlap corroborates the view that resource competition is a major factor shaping the composition of the four fish species. This study highlighted the low diversity of the food web within the Sundays River Valley irrigation ponds, where food items are shared by all the small-bodied fishes.
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Affiliation(s)
- Lubabalo Mofu
- Department of Ichthyology and Fisheries Science, Rhodes University, Makhanda, South Africa
- DSI/NRF Research Chair in Inland Fisheries and Freshwater Ecology, South African Institute for Aquatic Biodiversity (SAIAB), Makhanda, South Africa
- Centre for Invasion Biology, South African Institute for Aquatic Biodiversity (SAIAB), Makhanda, South Africa
| | - Tatenda Dalu
- School of Biology and Environmental Sciences, University of Mpumalanga, Nelspruit, South Africa
- South African Institute for Aquatic Biodiversity, Makhanda, South Africa
| | - Ryan J Wasserman
- South African Institute for Aquatic Biodiversity, Makhanda, South Africa
- Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
| | - Darragh J Woodford
- South African Institute for Aquatic Biodiversity, Makhanda, South Africa
- Centre for Invasion Biology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Olaf L F Weyl
- Department of Ichthyology and Fisheries Science, Rhodes University, Makhanda, South Africa
- DSI/NRF Research Chair in Inland Fisheries and Freshwater Ecology, South African Institute for Aquatic Biodiversity (SAIAB), Makhanda, South Africa
- Centre for Invasion Biology, South African Institute for Aquatic Biodiversity (SAIAB), Makhanda, South Africa
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Davidsen JG, Halvorsen AE, Eldøy SH, Thorstad EB, Vøllestad LA. Brown trout (Salmo trutta L. 1758) and Arctic charr [Salvelinus alpinus (L. 1758)] display different marine behaviour and feeding strategies in sympatry. JOURNAL OF FISH BIOLOGY 2023; 102:1129-1140. [PMID: 36815726 DOI: 10.1111/jfb.15354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/17/2023] [Indexed: 05/13/2023]
Abstract
Brown trout (Salmo trutta L. 1758) and Arctic charr [Salvelinus alpinus (L. 1758)] tagged with acoustic transmitters migrated from fresh water to the sea mainly in May and June, but with large individual variation in migration timing. For S. trutta, large individuals (42-86 cm total length) migrated earlier in the season than small individuals (18-27 cm). For S. alpinus, no such pattern was found, likely because of the small size range of tagged fish (28-41 cm). S. trutta stayed longer at sea than S. alpinus (average 2 vs. 1 month). Early migrants of S. trutta stayed for a shorter period at sea than late migrants, whereas no such pattern was observed for S. alpinus. Large S. trutta moved quickly away from the river and spent average 3 days to reach a receiver line 20 km from the river mouth, whereas small S. trutta and S. alpinus migrating that far spent 2-3 weeks on the same distance. S. trutta utilized the entire fjord system and had a greater proportion of long-distance migrants (>20 km, 78% and 59% of large and small S. trutta, respectively) than S. alpinus (29%). S. alpinus mostly stayed in the inner fjord areas, and none were recorded in the outermost part of the fjord. The difference in the use of marine areas may be caused by variation in prey choice and spatial distribution of the preferred prey groups. Stable isotope analysis showed that S. trutta had been feeding at a higher trophic level than S. alpinus. S. trutta had mainly fed on marine fish and shrimps, whereas S. alpinus had large proportions of freshwater invertebrates in the diet, suggesting that the estuary with benthos and amphipods drifting from the river was an important feeding habitat for S. alpinus. In conclusion, major differences in habitat use, migration patterns and feeding strategies were found between sympatric anadromous S. trutta and S. alpinus while at sea.
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Affiliation(s)
- Jan Grimsrud Davidsen
- Department of Natural history, NTNU University Museum, Norwegian University of Science and Technology, Trondheim, Norway
| | - Andrine Emilie Halvorsen
- Department of Biosciences, Center for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway
| | - Sindre Håvarstein Eldøy
- Department of Natural history, NTNU University Museum, Norwegian University of Science and Technology, Trondheim, Norway
| | | | - Leif Asbjørn Vøllestad
- Department of Biosciences, Center for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway
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