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Hou C, Zhao J, Ma Y, Wang Q, Liu Y, Zhang C, Wang L, Zhang W, Sun X, Zhang J, Dong Z, Yuan X. Impact of summer hypoxia on macrobenthic communities in a semi-enclosed bay: A long-term observation in the North Yellow sea of China. ENVIRONMENTAL RESEARCH 2024; 258:119433. [PMID: 38889838 DOI: 10.1016/j.envres.2024.119433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/31/2024] [Accepted: 06/15/2024] [Indexed: 06/20/2024]
Abstract
The O2 content of the global ocean has been declining progressively over the past decades, mainly because of human activities and global warming. Despite this situation, the responses of macrobenthos under hypoxic conditions remain poorly understood. In this study, we conducted a long-term observation (2015-2022) to investigate the intricate impact of summer hypoxia on macrobenthic communities in a semi-enclosed bay of the North Yellow Sea. Comparative analyses revealed higher macrobenthos abundance (1956.8 ± 1507.5 ind./m2 vs. 871.8 ± 636.9 ind./m2) and biomass (8.2 ± 4.1 g/m2 vs. 5.6 ± 3.2 g/m2) at hypoxic sites compared to normoxic sites during hypoxic years. Notably, polychaete species demonstrated remarkable adaptability, dominating hypoxic sites, and shaping community structure. The decline in biodiversity underscored the vulnerability and diminished resilience of macrobenthic communities to hypoxic stressors. Stable isotope analysis provided valuable insights into food web structures. The average trophic level of macrobenthos measured 2.84 ± 0.70 at hypoxic sites, contrasting with the higher value of 3.14 ± 0.74 observed at normoxic sites, indicating the absence of predators at high trophic levels under hypoxic conditions. Moreover, trophic interactions were significantly altered, resulting in a simplified and more vulnerable macrobenthic trophic structure. The findings underscored the importance of comprehensive research to understand the complex responses of macrobenthic communities to hypoxia, thereby informing future conservation efforts in impacted ecosystems.
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Affiliation(s)
- Chaowei Hou
- Muping Coastal Environment Research Station, Chinese Academy of Sciences, Yantai, 264100, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Jianmin Zhao
- Muping Coastal Environment Research Station, Chinese Academy of Sciences, Yantai, 264100, PR China; Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, PR China
| | - Yuanqing Ma
- Shandong Key Laboratory of Marine Ecological Restoration, Shandong Marine Resources and Environment Research Institute, Yantai, 264006, Shandong, PR China
| | - Qing Wang
- Muping Coastal Environment Research Station, Chinese Academy of Sciences, Yantai, 264100, PR China; Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, PR China
| | - Yongliang Liu
- Muping Coastal Environment Research Station, Chinese Academy of Sciences, Yantai, 264100, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Chen Zhang
- Muping Coastal Environment Research Station, Chinese Academy of Sciences, Yantai, 264100, PR China
| | - Lei Wang
- Muping Coastal Environment Research Station, Chinese Academy of Sciences, Yantai, 264100, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Wenjing Zhang
- Muping Coastal Environment Research Station, Chinese Academy of Sciences, Yantai, 264100, PR China
| | - Xiyan Sun
- Muping Coastal Environment Research Station, Chinese Academy of Sciences, Yantai, 264100, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Jinhao Zhang
- Yantai Marine Economic Research Institute, Yantai, 264003, PR China
| | - Zhijun Dong
- Muping Coastal Environment Research Station, Chinese Academy of Sciences, Yantai, 264100, PR China; Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, PR China
| | - Xiutang Yuan
- Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, PR China.
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2
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McLennan D, Auer SK, McKelvey S, McKelvey L, Anderson G, Boner W, Duprez JS, Metcalfe NB. Habitat restoration weakens negative environmental effects on telomere dynamics. Mol Ecol 2022; 31:6100-6113. [PMID: 33973299 DOI: 10.1111/mec.15980] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 04/16/2021] [Accepted: 04/27/2021] [Indexed: 02/01/2023]
Abstract
Habitat quality can have far-reaching effects on organismal fitness, an issue of concern given the current scale of habitat degradation. Many temperate upland streams have reduced nutrient levels due to human activity. Nutrient restoration confers benefits in terms of invertebrate food availability and subsequent fish growth rates. Here we test whether these mitigation measures also affect the rate of cellular ageing of the fish, measured in terms of the telomeres that cap the ends of eukaryotic chromosomes. We equally distributed Atlantic salmon eggs from the same 30 focal families into 10 human-impacted oligotrophic streams in northern Scotland. Nutrient levels in five of the streams were restored by simulating the deposition of a small number of adult Atlantic salmon Salmo salar carcasses at the end of the spawning period, while five reference streams were left as controls. Telomere lengths and expression of the telomerase reverse transcriptase (TERT) gene that may act to lengthen telomeres were then measured in the young fish when 15 months old. While TERT expression was unrelated to any of the measured variables, telomere lengths were shorter in salmon living at higher densities and in areas with a lower availability of the preferred substrate (cobbles and boulders). However, the adverse effects of these habitat features were much reduced in the streams receiving nutrients. These results suggest that adverse environmental pressures are weakened when nutrients are restored, presumably because the resulting increase in food supply reduces levels of both competition and stress.
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Affiliation(s)
- Darryl McLennan
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Sonya K Auer
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.,Department of Biology, Williams College, Williamstown, MA, USA
| | | | | | - Graeme Anderson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Winnie Boner
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Jessica S Duprez
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Neil B Metcalfe
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
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3
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Cárdenas-Alayza S, Adkesson MJ, Edwards MR, Hirons AC, Gutiérrez D, Tremblay Y, Franco-Trecu V. Sympatric otariids increase trophic segregation in response to warming ocean conditions in Peruvian Humboldt Current System. PLoS One 2022; 17:e0272348. [PMID: 35951498 PMCID: PMC9371314 DOI: 10.1371/journal.pone.0272348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 07/18/2022] [Indexed: 11/26/2022] Open
Abstract
Determining trophic habits of predator communities is essential to measure interspecific interactions and response to environmental fluctuations. South American fur seals, Arctocephalus australis (SAFS) and sea lions Otaria byronia (SASL), coexist along the coasts of Peru. Recently, ocean warming events (2014–2017) that can decrease and impoverish prey biomass have occurred in the Peruvian Humboldt Current System. In this context, our aim was to assess the effect of warming events on long-term inter- and intra-specific niche segregation. We collected whisker from SAFS (55 females and 21 males) and SASL (14 females and 22 males) in Punta San Juan, Peru. We used δ13C and δ15N values serially archived in otariid whiskers to construct a monthly time series for 2005–2019. From the same period we used sea level anomaly records to determine shifts in the predominant oceanographic conditions using a change point analysis. Ellipse areas (SIBER) estimated niche width of species-sex groups and their overlap. We detected a shift in the environmental conditions marking two distinct periods (P1: January 2005—October 2013; P2: November 2013—December 2019). Reduction in δ15N in all groups during P2 suggests impoverished baseline values with bottom-up effects, a shift towards consuming lower trophic level prey, or both. Reduced overlap between all groups in P2 lends support of a more redundant assemblage during the colder P1 to a more trophically segregated assemblage during warmer P2. SASL females show the largest variation in response to the warming scenario (P2), reducing both ellipse area and δ15N mean values. Plasticity to adapt to changing environments and feeding on a more available food source without fishing pressure can be more advantageous for female SASL, albeit temporary trophic bottom-up effects. This helps explain larger population size of SASL in Peru, in contrast to the smaller and declining SAFS population.
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Affiliation(s)
- Susana Cárdenas-Alayza
- Centro para la Sostenibilidad Ambiental, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorio de Ciencias del Mar, Universidad Peruana Cayetano Heredia, Lima, Peru
- UMR 248 MARBEC: IRD–Univ. Montpellier–CNRS–Ifremer, Sète cedex, France
- * E-mail:
| | - Michael J. Adkesson
- Chicago Zoological Society, Brookfield Zoo, Brookfield, Illinois, United States of America
| | - Mickie R. Edwards
- Halmos College of Arts and Sciences, Nova Southeastern University, Dania Beach, Florida, United States of America
| | - Amy C. Hirons
- Halmos College of Arts and Sciences, Nova Southeastern University, Dania Beach, Florida, United States of America
| | - Dimitri Gutiérrez
- Laboratorio de Ciencias del Mar, Universidad Peruana Cayetano Heredia, Lima, Peru
- Programa Maestría en Ciencias del Mar, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Yann Tremblay
- UMR 248 MARBEC: IRD–Univ. Montpellier–CNRS–Ifremer, Sète cedex, France
| | - Valentina Franco-Trecu
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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4
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Alp M, Cucherousset J. Food webs speak of human impact: Using stable isotope-based tools to measure ecological consequences of environmental change. FOOD WEBS 2022. [DOI: 10.1016/j.fooweb.2021.e00218] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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5
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A millennium of trophic stability in Atlantic cod (Gadus morhua): transition to a lower and converging trophic niche in modern times. Sci Rep 2021; 11:12681. [PMID: 34135440 PMCID: PMC8209007 DOI: 10.1038/s41598-021-92243-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/04/2021] [Indexed: 02/05/2023] Open
Abstract
Stable isotope analyses of zooarchaeological material can be used to examine ecological variability in exploited species at centennial to millennial scales. Climate change is a notable driver of marine ecosystem change, although historical fishing is also likely to have impacted past marine systems. Fishing removes the oldest and largest individuals and may thereby result in shorter trophic pathways and reduced niche width of predatory fish species. In the current study we examine the trophic niche of Atlantic cod, haddock and Atlantic wolffish, in the last millennium using δ13C and δ15N values of bone collagen. We report a lower trophic level of Atlantic cod and haddock but higher level of wolffish in present times, following centuries at consistent and higher trophic levels of Atlantic cod. This results in a concurrent converging trophic niche of the demersal fish. We suggest that the current data set provides a valuable historical baseline facilitating interpretation of current variability in the trophic ecology of northern demersal fish.
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6
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Qin C, Chen P, Sarà G, Mo B, Zhang A, Li X. Ecological implications of purple sea urchin (Heliocidaris crassispina, Agassiz, 1864) enhancement on the coastal benthic food web: evidence from stable isotope analysis. MARINE ENVIRONMENTAL RESEARCH 2020; 158:104957. [PMID: 32217297 DOI: 10.1016/j.marenvres.2020.104957] [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: 02/01/2020] [Revised: 03/10/2020] [Accepted: 03/10/2020] [Indexed: 06/10/2023]
Abstract
A responsible approach to marine stock enhancement is an effective approach to restore fishery resources. While the release strategy of target species has been well investigated, the impacts on local ecological equilibrium and habitat qualities have only been poorly considered. In the present study, we evaluated how the macro-benthic food web in Daya Bay was affected by purple sea urchin (Heliocidaris crassispina (Agassiz, 1864) stock enhancement using stable isotope analyses (δ13C and δ15N). Our results indicated that the distribution of local species and trophic diversity were influenced to a certain degree by release of purple sea urchins and changes in the feeding habit of the urchins were observed in line with food abundance, which seasonally varied. When food is abundant, the main food source of sea urchins was microphytobenthos and no significant differences were observed among sites; significant differences in the diet of purple sea urchins were detected when food is less abundant. These results suggested that optimization of the release strategy should include information on seasonal productivity of local recipient sites, food web structure and feeding habits of released species. Such information is essential for building a responsible release approach to maximize production enhancement.
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Affiliation(s)
- Chuanxin Qin
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources and Environment, Ministry of Agriculture, Guangzhou, 510300, China; Key Laboratory of Marine Ranching, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China
| | - Pimao Chen
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources and Environment, Ministry of Agriculture, Guangzhou, 510300, China; Key Laboratory of Marine Ranching, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China
| | - Gianluca Sarà
- Dipartimento di Scienze della Terra e del Mare, Università degli Studi di Palermo, Viale delle Scienze Ed. 16, 90128, Palermo, Italy.
| | - Baolin Mo
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources and Environment, Ministry of Agriculture, Guangzhou, 510300, China; Key Laboratory of Marine Ranching, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China
| | - Ankai Zhang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China
| | - Xiaoguo Li
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China; Scientific Observing and Experimental Station of South China Sea Fishery Resources and Environment, Ministry of Agriculture, Guangzhou, 510300, China; Key Laboratory of Marine Ranching, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China
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7
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Bas M, Salemme M, Green EJ, Santiago F, Speller C, Álvarez M, Briz I Godino I, Cardona L. Predicting habitat use by the Argentine hake Merluccius hubbsi in a warmer world: inferences from the Middle Holocene. Oecologia 2020; 193:461-474. [PMID: 32424465 DOI: 10.1007/s00442-020-04667-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 05/06/2020] [Indexed: 11/24/2022]
Abstract
Fish skeletal remains recovered from two archaeological sites dated in the Middle Holocene of Tierra del Fuego (Argentina) were analysed to describe habitat use patterns by hake in the past and predict changes in a warmer world. Mitochondrial DNA was successfully extracted and amplified from 42 out of 45 first vertebra from ancient hake and phylogenetic analysis assigned all haplotypes to Argentine hake (Merluccius hubbsi). According to osteometry, the Argentine hake recovered from the archaeological site were likely adults ranging 37.2-58.1 cm in standard length. C and N stable isotope analysis showed that currently Argentine hake use foraging grounds deeper than those of Patagonian blenny and pink cusk-eel. Argentine hake, however, had a much broader isotopic niche during the Middle Holocene, when a large part of the population foraged much shallower than contemporary pink cusk-eel. The overall evidence suggests the presence of large numbers of Argentine hake onshore Tierra del Fuego during the Middle Holocene, which allowed exploitation by hunter-gatherer-fisher groups devoid of fishing technology. Interestingly, average SST off Tierra del Fuego during the Middle Holocene was higher than currently (11 °C vs 7 °C) and matched SST in the current southernmost onshore spawning aggregations, at latitude 47 °S. This indicates that increasing SST resulting from global warming will likely result into an increased abundance of adult Argentine hake onshore Tierra del Fuego, as during the Middle Holocene. Furthermore, stable isotope ratios from mollusc shells confirmed a much higher marine primary productivity during the Middle Holocene off Tierra del Fuego.
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Affiliation(s)
- Maria Bas
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina. .,Department of Evolutionary Biology, Ecology and Environmental Science, Biodiversity Research Institute (IRBio), University of Barcelona, Barcelona, Spain.
| | - Mónica Salemme
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina.,ICSE, Universidad Nacional de Tierra del Fuego, Ushuaia, Argentina
| | | | - Fernando Santiago
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina
| | - Camilla Speller
- Department of Archaeology, BioArCh, University of York, York, UK.,Department of Anthropology, University of British Columbia, Vancouver, BC, Canada
| | - Myrian Álvarez
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina
| | - Ivan Briz I Godino
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina.,Department of Archaeology, University of York, York, UK.,P. Rockefeller Visiting Scholar, DRCLAS at Harvard University, Cambridge, MA, USA
| | - Luis Cardona
- Department of Evolutionary Biology, Ecology and Environmental Science, Biodiversity Research Institute (IRBio), University of Barcelona, Barcelona, Spain
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8
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Matich P, Kiszka JJ, Heithaus MR, Le Bourg B, Mourier J. Inter-individual differences in ontogenetic trophic shifts among three marine predators. Oecologia 2019; 189:621-636. [PMID: 30796523 DOI: 10.1007/s00442-019-04357-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 02/11/2019] [Indexed: 10/27/2022]
Abstract
Ontogenetic niche shifts are widespread. However, individual differences in size at birth, morphology, sex, and personalities can cause variability in behavior. As such, inherent inter-individual differences within populations may lead to context-dependent changes in behavior with animal body size, which is of concern for understanding population dynamics and optimizing ecological monitoring. Using stable carbon and nitrogen isotope values from concurrently sampled tissues, we quantified the direction and magnitude of intraspecific variation in trophic shifts among three shark species, and how these changed with body size: spurdogs (Squalus spp.) in deep-sea habitats off La Réunion, bull sharks (Carcharhinus leucas) in estuarine habitats of the Florida Everglades, and blacktip reef sharks (Carcharhinus melanopterus) in coral reef ecosystems of Moorea, French Polynesia. Intraspecific variation in trophic shifts was limited among spurdogs, and decreased with body size, while bull sharks exhibited greater individual differences in trophic shifts, but also decreased in variability through ontogeny. In contrast, blacktip reef sharks exhibited increased intraspecific variation in trophic interactions with body size. Variability in trophic interactions and ontogenetic shifts are known to be associated with changes in energetic requirements, but can vary with ecological context. Our results suggest that environmental stability may affect variability within populations, and ecosystems with greater spatial and/or temporal variability in environmental conditions, and those with more diverse food webs may facilitate greater individual differences in trophic interactions, and thus ontogenetic trophic shifts. In light of concerns over environmental disturbance, elucidating the contexts that promote or dampen phenotypic variability is invaluable for predicting population- and community-level responses to environmental changes.
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Affiliation(s)
- Philip Matich
- Marine Sciences Program, Florida International University, 3000 NE 151st, North Miami, FL, 33181, USA. .,Texas Research Institute for Environmental Studies, Sam Houston State University, 2424 Sam Houston Avenue, Huntsville, TX, 77341, USA.
| | - Jeremy J Kiszka
- Marine Sciences Program, Florida International University, 3000 NE 151st, North Miami, FL, 33181, USA
| | - Michael R Heithaus
- Marine Sciences Program, Florida International University, 3000 NE 151st, North Miami, FL, 33181, USA
| | - Baptiste Le Bourg
- LIttoral ENvironnement et Sociétés (LIENSs), UMR 7266 CNRS-Université de la Rochelle, 2 rue Olympe de Gouges, 17000, La Rochelle, France.,Laboratory of Oceanology, MARE Centre, Université de Liège, 4000, Liège, Belgium
| | - Johann Mourier
- PSL Research University: EPHE-UPVD-CNRS, USR 3278 CRIOBE, 66860, Perpignan, France.,Laboratoire d'excellence 'CORAIL', EPHE, PSL Research University, UPVD, CNRS, USR 3278 CRIOBE, Papetoai, Moorea, French Polynesia.,UMR MARBEC (IRD, Ifremer, Univ. Montpellier, CNRS), 34203, Sète, France
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9
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Bas M, Briz I Godino I, Álvarez M, Vales DG, Crespo EA, Cardona L. Back to the future? Late Holocene marine food web structure in a warm climatic phase as a predictor of trophodynamics in a warmer South-Western Atlantic Ocean. GLOBAL CHANGE BIOLOGY 2019; 25:404-419. [PMID: 30430698 DOI: 10.1111/gcb.14523] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 10/30/2018] [Accepted: 11/04/2018] [Indexed: 06/09/2023]
Abstract
Stable carbon and nitrogen isotope ratios in the skeletal elements of both ancient and modern marine species from the Beagle Channel were used to compare the structure of Late Holocene and modern food webs, and predict potential changes as a result of a Sea Surface Temperature (SST) increase in the region. Complementary, ancient and modern shells of limpets and mussels were isotopically analysed to explore changes in the isotopic baseline and compare marine food webs through time after an appropriate correction for baseline shifts. Results confirmed a declining pattern of marine primary productivity during the Late Holocene in the Beagle Channel. In general, the isotopic niches overlapped largely in the ancient food web in comparison to the current marine one, with the exception of that of cormorants (Phalacrocorax sp.). Our data suggest that all the species that have undergone intense human exploitation (Arctocephalus australis, Otaria flavescens and Merluccius sp.) significantly increased their trophic levels. The most important finding of this work was the very high isotopic overlap between snoek (Thyrsites atun) and hake (Merluccius sp.) during the Late Holocene. Increasing SST as a result of global warming could favour the recolonization of the southern South-Western Atlantic Ocean by snoek from the South-Eastern Pacific Ocean, with a potential impact on the landings of the economically important Argentine and Austral hake. These findings highlight the relevance of using zooarchaeological remains for providing predictions about marine food webs changes in the near future.
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Affiliation(s)
- Maria Bas
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina
- Biodiversity Research Institute (IRBio), University of Barcelona, Barcelona, Spain
| | - Ivan Briz I Godino
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina
- Department of Archaeology, University of York, York, UK
| | - Myrian Álvarez
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), Ushuaia, Argentina
| | - Damián G Vales
- Centro para el Estudio de Sistemas Marinos (CESIMAR - CCT CONICET - CENPAT), Puerto Madryn, Argentina
| | - Enrique A Crespo
- Centro para el Estudio de Sistemas Marinos (CESIMAR - CCT CONICET - CENPAT), Puerto Madryn, Argentina
| | - Luis Cardona
- Biodiversity Research Institute (IRBio), University of Barcelona, Barcelona, Spain
- Department of Evolutionary Biology, Ecology and Environmental Science, University of Barcelona, Barcelona, Spain
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10
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Bas M, Cardona L. Effects of skeletal element identity, delipidation and demineralization on the analysis of stable isotope ratios of C and N in fish bone. JOURNAL OF FISH BIOLOGY 2018; 92:420-437. [PMID: 29235096 DOI: 10.1111/jfb.13521] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
Stable isotope ratios of C and N in the bone tissue of three different skeletal elements (angular, cleithrum and vertebra) of three fish species from different evolutionary lineages (Clupeiformes, Atheriniformes and Notothenioidei) were determined before (δ13 Cbulk and δ15 Nbulk ) and after demineralization and delipidation (δ13 Cdml and δ15 Ndml ). One of the species had cellular bone and the other two had acellular bone. Results revealed that δ15 N and δ13 C values from different skeletal elements were interchangeable in species with acellular bone, but caution was needed in species with cellular bone, as δ15 N values varied among skeletal elements. Furthermore, δ15 Nbulk values were significantly lower than δ15 Ndml values in the three species, thus suggesting that they are not comparable. This difference is probably because δ15 Nbulk refers to total bone protein and δ15 Ndml to collagen only.
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Affiliation(s)
- M Bas
- Centro Austral de Investigaciones Científicas (CADIC-CONICET), C/Bernardo Houssay 200, 9410, Ushuaia, Argentina
- Biodiversity Research Institute (IRBio), University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - L Cardona
- Biodiversity Research Institute (IRBio), University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
- Department of Evolutionary Biology, Ecology and Environmental Science, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
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11
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Drago M, Cardona L, Franco-Trecu V, Crespo EA, Vales DG, Borella F, Zenteno L, Gonzáles EM, Inchausti P. Isotopic niche partitioning between two apex predators over time. J Anim Ecol 2017; 86:766-780. [PMID: 28326539 DOI: 10.1111/1365-2656.12666] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 03/01/2017] [Indexed: 11/26/2022]
Abstract
Stable isotope analyses have become an important tool in reconstructing diets, analysing resource use patterns, elucidating trophic relations among predators and understanding the structure of food webs. Here, we use stable carbon and nitrogen isotope ratios in bone collagen to reconstruct and compare the isotopic niches of adult South American fur seals (Arctocephalus australis; n = 86) and sea lions (Otaria flavescens; n = 49) - two otariid species with marked morphological differences - in the Río de la Plata estuary (Argentina - Uruguay) and the adjacent Atlantic Ocean during the second half of the 20th century and the beginning of the 21st century. Samples from the middle Holocene (n = 7 fur seals and n = 5 sea lions) are also included in order to provide a reference point for characterizing resource partitioning before major anthropogenic modifications of the environment. We found that the South American fur seals and South American sea lions had distinct isotopic niches during the middle Holocene. Isotopic niche segregation was similar at the beginning of the second half of the 20th century, but has diminished over time. The progressive convergence of the isotopic niches of these two otariids during the second half of the 20th century and the beginning of the 21st century is most likely due to the increased reliance of South American fur seals on demersal prey. This recent dietary change in South American fur seals can be explained by at least two non-mutually exclusive mechanisms: (i) the decrease in the abundance of sympatric South American sea lions as a consequence of small colony size and high pup mortality resulting from commercial sealing; and (ii) the decrease in the average size of demersal fishes due to intense fishing of the larger class sizes, which may have increased their accessibility to those eared seals with a smaller mouth gape, that is, South American fur seals of both sexes and female South American sea lions.
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Affiliation(s)
- Massimiliano Drago
- Departamento de Ecología & Evolución, Centro Universitario Regional Este (CURE), Universidad de la República, Tacuarembó s/n, 20000, Maldonado, Uruguay
| | - Luis Cardona
- IRBio y Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Universidad de Barcelona, Av. Diagonal 643, 08028, Barcelona, España
| | - Valentina Franco-Trecu
- Departamento de Ecología & Evolución, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400, Montevideo, Uruguay
| | - Enrique A Crespo
- Laboratorio de Mamíferos Marinos, Centro para el Estudio de Sistemas Marinos (CESIMAR - CCT CONICET-CENPAT), Blvd. Brown 2915, U9120ACD, Puerto Madryn, Argentina.,Universidad Nacional de la Patagonia, Blvd. Brown 3600, U9120ACD, Puerto Madryn, Argentina
| | - Damián G Vales
- Laboratorio de Mamíferos Marinos, Centro para el Estudio de Sistemas Marinos (CESIMAR - CCT CONICET-CENPAT), Blvd. Brown 2915, U9120ACD, Puerto Madryn, Argentina
| | - Florencia Borella
- Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano (INCUAPA-CONICET), Universidad Nacional del Centro, Av. Del Valle 5737, B7400JWI, Olavarría, Argentina
| | - Lisette Zenteno
- IRBio y Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Universidad de Barcelona, Av. Diagonal 643, 08028, Barcelona, España
| | - Enrique M Gonzáles
- Museo Nacional de Historia Natural, 25 de Mayo 582, 11000, Montevideo, Uruguay
| | - Pablo Inchausti
- Departamento de Ecología & Evolución, Centro Universitario Regional Este (CURE), Universidad de la República, Tacuarembó s/n, 20000, Maldonado, Uruguay
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Holocene changes in the trophic ecology of an apex marine predator in the South Atlantic Ocean. Oecologia 2016; 183:555-570. [PMID: 27900469 DOI: 10.1007/s00442-016-3781-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/14/2016] [Indexed: 10/20/2022]
Abstract
Predators may modify their diets as a result of both anthropogenic and natural environmental changes. Stable isotope ratios of nitrogen and carbon in bone collagen have been used to reconstruct the foraging ecology of South American fur seals (Arctocephalus australis) in the southwestern South Atlantic Ocean since the Middle Holocene, a region inhabited by hunter-gatherers by millennia and modified by two centuries of whaling, sealing and fishing. Results suggest that the isotopic niche of fur seals from Patagonia has not changed over the last two millennia (average for the period: δ13C2200-0BP = -13.4 ± 0.5‰, δ15N2200-0BP = 20.6 ± 1.1‰). Conversely, Middle Holocene fur seals fed more pelagically than their modern conspecifics in the Río de la Plata region (δ13C7000BP = -15.9 ± 0.6‰ vs. δ13CPRESENT = -13.5 ± 0.8‰) and Tierra del Fuego (δ13C6400-4300BP = -15.4 ± 0.5‰ vs. δ13CPRESENT = -13.2 ± 0.7‰). In the latter region, Middle Holocene fur seals also fed at a higher trophic level than their modern counterparts (δ15N6400-4300BP = 20.5 ± 0.5‰ vs. δ15NPRESENT = 19.0 ± 1.6‰). Nevertheless, a major dietary shift was observed in fur seals from Tierra del Fuego during the nineteenth century (δ13C100BP = -17.2 ± 0.3‰, δ15N100BP = 18.6 ± 0.7‰), when marine primary productivity plummeted and the fur seal population was decimated by sealing. Disentangling the relative roles of natural and anthropogenic factors in explaining this dietary shift is difficult, but certainly the trophic position of fur seals has changed through the Holocene in some South Atlantic regions.
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