1
|
Dias E, Morais P, Antunes C, Hoffman JC. The benthic food web connects the estuarine habitat mosaic to adjacent ecosystems. FOOD WEBS 2023; 35:e00282. [PMID: 37731992 PMCID: PMC10508047 DOI: 10.1016/j.fooweb.2023.e00282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Energy flows from land to sea and between pelagic and benthic environments have the potential to increase the connectivity between estuaries and adjacent ecosystems as well as among estuarine habitats. To identify such energy flows and the main trophic pathways of energy transfer in the Minho River estuary, we investigated the spatial and temporal fluctuations of carbon and nitrogen stable isotope ratios in benthic (and their potential food sources) and epibenthic consumers. Sampling was conducted along the estuarine salinity gradient from winter to summer of 2011. We found that the carbon (δ13C = 13C/12C) and nitrogen (δ15N = 15N/14N) stable isotope ratios of the most abundant benthic and epibenthic consumers varied along the salinity gradient. The δ13C values increased seaward, whereas the opposite pattern was found for the δ15N, especially during the summer. The stable isotope ratios revealed two trophic pathways in the Minho estuary food web. The first pathway is supported by phytoplankton and represented by filter feeders such as zooplankton and some deposit feeders, particularly amphipods and polychaetes. The second pathway is supported by detritus and composed essentially of deposit feeders, which by being consumed, allow detritus to be incorporated into higher trophic levels. Spatial and temporal feeding variations in the estuarine benthic food web are driven by hydrology and proximity to adjacent ecosystems (terrestrial, marine). During high river discharge periods, the δ13CPOC (ca. -28‰) and C: NPOM (>10) values suggested an increase of terrestrial-derived OM to the particulate OM pool, which was then used by suspension feeders. During low river discharge periods, marine intrusion increased upriver, which was reflected in benthic consumers' 13C-enriched stable isotope values. No relationship was found between food quality (phytoplankton vs. detritus) and food chain length because the lowest and highest values were associated with freshwater and saltmarsh areas, respectively, both dominated by the detrital pathway. This study demonstrates that benthic consumers enhance the connectivity between estuaries and its adjacent ecosystems by utilizing subsidies of terrestrial and marine origin and that benthic-pelagic coupling is an important energy transfer mechanism to the benthic food web.
Collapse
Affiliation(s)
- Ester Dias
- CIIMAR – Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida Norton de Matos, 4450-208 Matosinhos, Portugal
| | - Pedro Morais
- CCMAR – Centre of Marine Sciences, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Carlos Antunes
- CIIMAR – Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida Norton de Matos, 4450-208 Matosinhos, Portugal
- Aquamuseu do Rio Minho, Parque do Castelinho s/n, 4920-290 Vila Nova de Cerveira, Portugal
| | - Joel C. Hoffman
- Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Exposure, US Environmental Protection Agency Office of Research and Development, 6201 Congdon Blvd, Duluth, MN 55804, USA
| |
Collapse
|
2
|
Maceda-Veiga A, Nally RM, de Sostoa A, Yen JDL. Patterns of species richness, abundance and individual-size distributions in native stream-fish assemblages invaded by exotic and translocated fishes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:155953. [PMID: 35588834 DOI: 10.1016/j.scitotenv.2022.155953] [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: 12/22/2021] [Revised: 05/09/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
Predicting the impacts of species introductions long has attracted the attention of ecologists yet there still is limited insight into how impacts on native assemblages vary with the degree of shared evolutionary context. Here, we used data from 535 stream-fish surveys from 15 catchments in north-eastern Spain (99,700 km2) to explore whether the relative effects on native fishes differ between fish introductions from two different ecoregions (i.e., evolutionary contexts), namely, catchments within Iberian Peninsula (i.e., 'translocated species') and catchments beyond Iberian Peninsula (i.e., 'exotic fishes'). We used hierarchical Bayesian models to relate taxon richness, abundance, and the individual-size distributions (ISDs) of native fishes to the presence, abundance, and weighted trophic level (TL) of translocated and exotic fishes, conditional on geographic and habitat covariates. Environmental covariates dominated the percentage of explained variance (≥ 65%) for all responses. Translocated fishes accounted for more of the explained variance than did exotic fishes for ISDs and abundance, but not for native fish species richness. The presence of translocated fishes was associated with lower abundance and richness of native fishes, with individuals being smaller in the presence of translocated fishes of higher TL. The presence of exotic fishes was associated with a greater abundance and richness of native fishes, with individuals generally being larger in the presence of exotic fishes. Our study suggests that translocated fishes could be as problematic as exotic fishes when angling and water transfers among catchments to deal with climate change may increase the establishment of translocated fishes. We also discuss the difficulties of using fish body size as species-blind, transferable assemblage-level trait in fish monitoring.
Collapse
Affiliation(s)
- Alberto Maceda-Veiga
- Integrative Zoology Lab, Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona (UB), 08028 Barcelona, Spain; Institut de Recerca de la Biodiversitat, Universitat de Barcelona (IRBio), Avda. Diagonal, 643, 08028 Barcelona, Spain.
| | - Ralph Mac Nally
- School of BioSciences, The University of Melbourne, Melbourne 3010, VIC, Australia
| | - Adolfo de Sostoa
- Integrative Zoology Lab, Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona (UB), 08028 Barcelona, Spain; Institut de Recerca de la Biodiversitat, Universitat de Barcelona (IRBio), Avda. Diagonal, 643, 08028 Barcelona, Spain
| | - Jian D L Yen
- School of BioSciences, The University of Melbourne, Melbourne 3010, VIC, Australia; Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria 3084, Australia
| |
Collapse
|
3
|
Regional Population Structure of the European Eel at the Southern Limit of Its Distribution Revealed by Otolith Shape Signature. FISHES 2022. [DOI: 10.3390/fishes7030135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Given the European eel population’s marked decrease since the 1980s, it has become urgent to collect information describing its regional population structure to improve management plans. The Minho River (NW-Portugal, SW-Europe) is an important basin for the eel at the southern limit of its distribution, but the species is poorly described. Thus, we aimed to study the structure of the European eel population in the Minho River using otolith shape analysis, which has proven to be effective in discriminating fish groups experiencing different environmental conditions through ontogeny. Our results showed complete discrimination between the two main types of habitats studied (tributaries and estuaries). Otoliths of eels from the estuary were rectangular and elliptic, whereas in the tributaries they presented a more round and circular form. Eels collected in both habitats were mostly yellow-stage eels with a similar age range, but the eels from the tributaries showed smaller length-at-age and lower body condition than those collected in the estuary. Additionally, the sex ratio was skewed towards males in the tributaries and females in the estuary. This study reveals that there are at least two distinct groups of eels in this basin, likely with different development characteristics.
Collapse
|
4
|
Taxonomic and Functional Responses of Species-Poor Riverine Fish Assemblages to the Interplay of Human-Induced Stressors. WATER 2022. [DOI: 10.3390/w14030355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of human-induced stressors on riverine fish assemblages are still poorly understood, especially in species-poor assemblages such as those of temperate South American rivers. In this study we evaluated the effects of human-induced stressors on the taxonomic and functional facets of fish assemblages of two central-southern Chilean rivers: the Biobío River (flow regulated by multiple dams) and the Valdivia River (free-flowing). The study design considered reference condition, urban polluted, and urban-industrial polluted sites. To evaluate the effects of stressors on fish assemblages we assessed: (i) components of beta diversity; (ii) spatial and temporal patterns of fish structure using a multivariate approach; and (iii) functional diversity (specialization, originality, dispersion, and entropy) using linear models. We found a strong association between taxonomic and functional fish assemblage facets with a predominance of natural processes in the Valdivia River reflected in marked temporal dynamics. In contrast, the Biobío River showed a clear loss of association with seasonal pattern, and both taxonomic and functional facets appeared to respond significantly to pollution zones. Implementation of stricter environmental policies and integrated river basin management are instrumental for conserving species-poor fish assemblages in Chilean temperate rivers characterized by low functional traits redundancy.
Collapse
|
5
|
Wang S, Su LH, Luo BK, Qin YJ, Stewart SD, Tang JP, Wang TT, Yang Y, Cheng G. Stable isotopes reveal effects of natural drivers and anthropogenic pressures on isotopic niches of invertebrate communities in a large subtropical river of China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:36132-36146. [PMID: 32557028 DOI: 10.1007/s11356-020-09252-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
Isotopic niches reflect the basic structure and functioning of river food webs; however, their response to riverine environments remains unclear. We used stable isotope analysis and community-wide metrics to quantify how invertebrate niches vary with environmental changes along a large subtropical river in China. Eight niche metrics, which had higher values in the wet than in the dry season, increased from headwaters to the middle river and decreased sharply near the estuarine industrial zones. The δ13C value of > - 23.8‰, which indicated consumption of epilithic diatoms, separated the invertebrates between the upper and mid-lower reaches. The δ15N values > 9.4‰ identified site-specific nitrogen sources from manure (e.g., animal effluent) and domestic sewage in agricultural area. The output of mixing models showed a downstream shift in carbon utilization by invertebrates from autochthonous periphyton and submerged hydrophytes to allochthonous C3 plants. Principle component (PC) and cluster analysis decomposed and grouped 40 environmental variables into 4 PCs that explained 84.5% of the total variance. Hierarchical partitioning revealed that the second and first PCs, which were driven mainly by biological indicators and habitat characteristics, had the highest explanatory power for niche ranges and areas (e.g., Bayesian ellipse), respectively. Our results suggest that reducing anthropogenic pressures (e.g., habitat loss and water pollution) on river ecosystems through measures, such as protecting diatom-dominated biofilms in riffles and controlling nitrogen loading in rural regions, may produce the greatest impact for river management. Graphical abstract.
Collapse
Affiliation(s)
- Sai Wang
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou, 510632, China
- Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education Engineering, Jinan University, Guangzhou, 510632, China
| | - Lin-Hui Su
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou, 510632, China
- Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education Engineering, Jinan University, Guangzhou, 510632, China
| | - Bang-Ke Luo
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou, 510632, China
| | - Ying-Jun Qin
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou, 510632, China
| | | | - Jin-Peng Tang
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou, 510632, China
- Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education Engineering, Jinan University, Guangzhou, 510632, China
| | - Tuan-Tuan Wang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Yang Yang
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou, 510632, China.
- Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education Engineering, Jinan University, Guangzhou, 510632, China.
| | - Gong Cheng
- Environmental Engineering Center, Shenzhen Academy of Environmental Sciences, Shenzhen, 518001, China.
| |
Collapse
|
6
|
Cano-Rocabayera O, de Sostoa A, Coll L, Maceda-Veiga A. Managing small, highly prolific invasive aquatic species: Exploring an ecosystem approach for the eastern mosquitofish (Gambusia holbrooki). THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 673:594-604. [PMID: 30999100 DOI: 10.1016/j.scitotenv.2019.02.460] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
Invasive exotic species threaten native biodiversity worldwide and their management is on the agenda of an increasing number of countries. We explored the potential of an ecosystem approach for the natural control of Gambusia holbrooki, which is among the most pernicious and widely distributed fish invaders. Individual-based linear mixed models were used to identify the ecosystem factors (conspecific density, environment and piscivorous birds) that most influenced life-history variation in male and female G. holbrooki (N = 654). All traits (body condition, growth, length, gonad weight, offspring size and number, real and potential fertility) were associated with at least one ecosystem factor from the 18 water bodies surveyed in north-eastern Spain. Models for female reproductive traits had the highest fit (R2 = 0.89) and those for body condition in both sexes the lowest (0.12). The life history of G. holbrooki was mostly affected by its density; increasing offspring number at the expense of offspring size at the sites with the highest fish density. Weaker effects on G. holbrooki life history were observed for the abundance of piscivorous birds and water-quality conditions, including turbidity and nutrient concentrations. Although effects were not consistent between traits, outputs supported that G. holbrooki has a wide tolerance to changes in water quality. Therefore, actions based solely on environmental changes within the range tested probably will fail in reducing the proliferation of G. holbrooki, especially if its body condition improved at the most naturalised sites. Overall, this study suggests that the management of G. holbrooki using ecologically sound treatments is likely to be very difficult in stagnant waters. Preventing new introductions and direct removal once established are the most appropriate actions for the management of this small, highly prolific fish invader.
Collapse
Affiliation(s)
- Oriol Cano-Rocabayera
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Institute of Research in Biodiversity (IRBio-UB), Universitat de Barcelona, Spain.
| | - Adolfo de Sostoa
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Institute of Research in Biodiversity (IRBio-UB), Universitat de Barcelona, Spain
| | - Lluís Coll
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Institute of Research in Biodiversity (IRBio-UB), Universitat de Barcelona, Spain
| | - Alberto Maceda-Veiga
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Institute of Research in Biodiversity (IRBio-UB), Universitat de Barcelona, Spain; Department of Integrative Ecology, Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain
| |
Collapse
|