1
|
Lejeune B, Kopp D, Mehault S, Mouchet MA. Assessing the diet and trophic level of marine fauna in a fishing ground subject to discarding activity using stable isotopes. PLoS One 2022; 17:e0268758. [PMID: 35671294 PMCID: PMC9173610 DOI: 10.1371/journal.pone.0268758] [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: 10/28/2021] [Accepted: 05/06/2022] [Indexed: 12/05/2022] Open
Abstract
Discarding practices have become a source of concern for the perennation of marine resources, prompting efforts of discard reduction around the globe. However, little is known about the fate of discards in marine environments. Discarding may provide food for various marine consumers, potentially affecting food web structure and stability. Yet, quantifying reliance upon discards is difficult because identity and frequency of discards may change according to multiple factors, and most previously used diet assessment techniques do not allow to assume consistency of feeding strategies over time. One currently untested hypothesis is that significant contribution of discards over time should reflect in increased trophic level (TL) of marine fauna, particularly in low TL consumers. Here, we explored this hypothesis by modeling the TL and assimilated diet of consumers living in fishing grounds subject to important discarding activity using stable isotope analysis. We found indications that benthic invertebrates and Chondrichthyes may depict a higher than expected TL, while other fish tend to depict similar to lower TL compared to global averages from the literature. Based on prior knowledge of discard consumption in the same area, stable isotope mixing models congruently revealed that discards may represent substantial portions of the assimilated diet of most benthic invertebrate macrofauna, cephalopods and Chondrichthyes. We highlight limitations and challenges of currently used diet assessment techniques to study discard consumption and stress that understanding their reintegration in marine food webs is crucial in the context of an ecosystem approach to fisheries management and to better understand the functioning of marine ecosystems subject to fishing.
Collapse
Affiliation(s)
- Benjamin Lejeune
- Centre d’Ecologie et de Sciences de la Conservation, CNRS-MNHN-SU, Paris, France
- DECOD (Ecosystem Dynamics and Sustainability), IFREMER, INRAE, Institut Agro—Agrocampus Ouest, Lorient, France
- * E-mail:
| | - Dorothée Kopp
- DECOD (Ecosystem Dynamics and Sustainability), IFREMER, INRAE, Institut Agro—Agrocampus Ouest, Lorient, France
| | - Sonia Mehault
- DECOD (Ecosystem Dynamics and Sustainability), IFREMER, INRAE, Institut Agro—Agrocampus Ouest, Lorient, France
| | - Maud Aline Mouchet
- Centre d’Ecologie et de Sciences de la Conservation, CNRS-MNHN-SU, Paris, France
| |
Collapse
|
3
|
Vilar CC, Andrades R, Szablak FT, Guabiroba HC, Pichler HA, Bastos KV, de Lima LRS, Bastos PGP, Martins RF, Rodrigues VLA, Hostim-Silva M, Joyeux JC. Variability in nearshore fish biodiversity indicators after a mining disaster in eastern Brazil. MARINE ENVIRONMENTAL RESEARCH 2022; 175:105565. [PMID: 35114588 DOI: 10.1016/j.marenvres.2022.105565] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/24/2021] [Accepted: 01/16/2022] [Indexed: 06/14/2023]
Abstract
The rupture of the Fundão mining dam (Doce river basin, Brazil) caused a wide range of negative impacts. Yet, assemblage-level implications to estuarine and coastal fishes remain unclear, partly due to the lack of pre-disaster information. Based on monthly otter trawl surveys, we analyzed spatial and seasonal variability in univariate (total biomass, biomass of species vulnerable to exploitation, rarefied richness and evenness) and multivariate (species composition and trophic composition) indicators of fish biodiversity in the Doce river delta, eastern Brazil. We determined the independent and interactive effects of environmental, seasonal and spatial variables on species composition to test whether environmental alterations provoked by mine tailings could affect assemblage's organization. Most indicators present idiosyncratic spatiotemporal patterns, suggesting they have complementary roles in revealing changes in fish biodiversity. Environmental variables, including those affected by the Fundão dam collapse such as turbidity, dissolved oxygen and pH, were much more important than seasonal and spatial predictors in explaining the variation in fish species composition. These findings highlight the potential from mine tailings to disrupt local ichthyofauna and indicate a preponderant role of environmental conditions in assemblage structuring. Given the lack of data prior to rupture, our results may be used as a baseline against which to assess temporal trends in fish biodiversity relative to changes detected in less disturbed estuarine and coastal assemblages.
Collapse
Affiliation(s)
- Ciro Colodetti Vilar
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil.
| | - Ryan Andrades
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil
| | - Flávio Toscano Szablak
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil
| | - Helder Coelho Guabiroba
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil
| | - Helen Audrey Pichler
- Laboratório de Ecologia de Peixes Marinhos, Departamento de Ciências Agrárias e Biológicas, Universidade Federal do Espírito Santo, BR 101, km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil
| | - Kathiani Victor Bastos
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil
| | - Layza Roxanne Santana de Lima
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil
| | - Pedro Garcia Pereira Bastos
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil
| | - Rebeka Ferreira Martins
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil
| | - Vitor Leonardo Amaral Rodrigues
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil
| | - Mauricio Hostim-Silva
- Laboratório de Ecologia de Peixes Marinhos, Departamento de Ciências Agrárias e Biológicas, Universidade Federal do Espírito Santo, BR 101, km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Instituto Meros do Brasil, Rua Benjamin Cosntant, 67, Conj. 1104, 10° andar, Curitiba, PR, Brazil
| | - Jean-Christophe Joyeux
- Laboratório de Ictiologia, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES, 29055-460, Brazil
| |
Collapse
|