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Abstract
Bycatch and discards are a significant issue for global fisheries, with discards considered unnecessary mortality and wasted fishing. Discards have declined due to more selective gear and changes in regulations, but data on discard rates and species remains challenging to collect. Addressing discards is crucial to minimize food waste and increase seafood production. We provide an up-to-date overview of research on wasted fishing through bycatch and discards since 2012, including pots/traps, trawls, gillnets, and lines. By highlighting the challenges of collecting data on discard rates, species, and reasons, we emphasize the need for an adaptive approach to monitoring and reducing discards. Our review provides an important update on the current state of research on wasted fishing and highlights ongoing knowledge gaps in this area, indicating a need for continued efforts towards sustainable fisheries management.
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Affiliation(s)
- Julie A Lively
- School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA, United States.
| | - Jonathan McKenzie
- School of Pure and Applied Sciences, Florida South Western State College, Fort Myers, FL, United States
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2
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Závorka L, Blanco A, Chaguaceda F, Cucherousset J, Killen SS, Liénart C, Mathieu-Resuge M, Němec P, Pilecky M, Scharnweber K, Twining CW, Kainz MJ. The role of vital dietary biomolecules in eco-evo-devo dynamics. Trends Ecol Evol 2023; 38:72-84. [PMID: 36182405 DOI: 10.1016/j.tree.2022.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/30/2022] [Accepted: 08/31/2022] [Indexed: 12/30/2022]
Abstract
The physiological dependence of animals on dietary intake of vitamins, amino acids, and fatty acids is ubiquitous. Sharp differences in the availability of these vital dietary biomolecules among different resources mean that consumers must adopt a range of strategies to meet their physiological needs. We review the emerging work on omega-3 long-chain polyunsaturated fatty acids, focusing predominantly on predator-prey interactions, to illustrate that trade-off between capacities to consume resources rich in vital biomolecules and internal synthesis capacity drives differences in phenotype and fitness of consumers. This can then feedback to impact ecosystem functioning. We outline how focus on vital dietary biomolecules in eco-eco-devo dynamics can improve our understanding of anthropogenic changes across multiple levels of biological organization.
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Affiliation(s)
- Libor Závorka
- WasserCluster Lunz - Biologische Station, Inter-university Centre for Aquatic Ecosystem Research, A-3293 Lunz am See, Austria.
| | - Andreu Blanco
- Centro de Investigación Mariña, Universidade de Vigo, EcoCost, Campus de Vigo, As Lagoas, Marcosende, 36310, Vigo, Spain
| | - Fernando Chaguaceda
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, 750 07 Uppsala, Sweden
| | - Julien Cucherousset
- Laboratoire Evolution et Diversité Biologique (UMR 5174 EDB), CNRS, Université Paul Sabatier - Toulouse III, 31062 Toulouse, France
| | - Shaun S Killen
- School of Biodiversity, One Health & Veterinary Medicine, Graham Kerr Building, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Camilla Liénart
- Tvärminne Zoological Station, University of Helsinki, J.A. Palménin tie 260, Hanko, 10900, Finland
| | - Margaux Mathieu-Resuge
- WasserCluster Lunz - Biologische Station, Inter-university Centre for Aquatic Ecosystem Research, A-3293 Lunz am See, Austria; Université de Brest, CNRS, IRD, Ifremer, LEMAR, 29280 Plouzané, Brittany, France; UMR DECOD (Ecosystem Dynamics and Sustainability), Ifremer, INRAE, Institut Agro, Plouzané, France
| | - Pavel Němec
- Department of Zoology, Faculty of Science, Charles University, CZ-12844 Prague, Czech Republic
| | - Matthias Pilecky
- WasserCluster Lunz - Biologische Station, Inter-university Centre for Aquatic Ecosystem Research, A-3293 Lunz am See, Austria; Danube University Krems, Dr. Karl Dorrek Straße 30, A-3500 Krems, Austria
| | - Kristin Scharnweber
- University of Potsdam, Plant Ecology and Nature Conservation, Am Mühlenberg 3, 14476 Potsdam, Germany
| | - Cornelia W Twining
- Department of Fish Ecology and Evolution, Eawag - Swiss Federal Institute of Aquatic Science and Technology, Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
| | - Martin J Kainz
- WasserCluster Lunz - Biologische Station, Inter-university Centre for Aquatic Ecosystem Research, A-3293 Lunz am See, Austria; Danube University Krems, Dr. Karl Dorrek Straße 30, A-3500 Krems, Austria
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3
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Pecuchet L, Jørgensen LL, Dolgov AV, Eriksen E, Husson B, Skern‐Mauritzen M, Primicerio R. Spatio‐temporal turnover and drivers of bentho‐demersal community and food web structure in a high‐latitude marine ecosystem. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
| | | | - Andrey V. Dolgov
- Polar Branch of Russian Federal Research Institute of Fisheries and Oceanography (PINRO named after N.M.Knipovich) Murmansk Russia
- Murmansk State Technical University Murmansk Russia
- Tomsk State University Tomsk Russia
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4
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Modeling Discards in Stock Assessments: Red Grouper Epinephelus morio in the U.S. Gulf of Mexico. FISHES 2021. [DOI: 10.3390/fishes7010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To be as accurate as possible, stock assessments should account for discard mortality in fisheries if it occurs. Three common approaches to modeling discards in assessments are to lump dead discards with landings, treat dead discards as their own fleet, or link them conversely with landings through use of a retention function. The first approach (lumping) implicitly assumes that the selectivity of landings applies also to discards. In many cases, that assumption is false, for example, if discards comprise smaller fish than do landings. The latter two approaches avoid the assumption by modeling discards explicitly with their own selectivity pattern. Here, we examine these approaches to modeling discards. Using a simulation study, we demonstrate that the two approaches to modeling discards explicitly can provide identical results under both static and time-varying conditions. Then, using a stock assessment case study of red grouper Epinephelus morio in the U.S. Gulf of Mexico, we demonstrate that in practice the approaches to modeling discards can provide different outcomes, with implications for the resultant management advice. We conclude by comparing and contrasting the different approaches, calling for more research to elucidate which approach is most suitable under various sources of error typically encountered in discard data.
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Lira AS, Lucena-Frédou F, Ménard F, Frédou T, Gonzalez JG, Ferreira V, Filho JSR, Munaron JM, Le Loc’h F. Trophic structure of a nektobenthic community exploited by a multispecific bottom trawling fishery in Northeastern Brazil. PLoS One 2021; 16:e0246491. [PMID: 33556099 PMCID: PMC7870051 DOI: 10.1371/journal.pone.0246491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 01/19/2021] [Indexed: 11/18/2022] Open
Abstract
We used complementary stable isotope (SIA) and stomach content (SCA) analyses to investigate feeding relationships among species of the nektobenthic communities and the potential ecological effects of the bottom trawling of a coastal ecosystem in northeastern Brazil. Carbon (δ13C) and nitrogen (δ15N) compositions were determined for five basal sources and 28 consumers, from zooplankton to shrimp and fish species. Fishes and basal sources showed a broad range of δ15N (fishes: 6.49-14.94‰; sources: 2.58-6.79‰) and δ13C values (fishes: -23.86 to -13.71‰; sources: -24.32 to -13.53‰), while shrimps and crabs exhibited similar nitrogen and carbon ratios. Six trophic consumer groups were determined among zooplankton, crustaceans and fishes by SIA, with trophic pathways associated mostly with benthic sources. SCA results indicated a preference for benthic invertebrates, mainly worms, crabs and shrimps, as prey for the fish fauna, highlighting their importance in the food web. In overall, differences between SCA and the SIA approaches were observed, except for groups composed mainly for shrimps and some species of high δ15N values, mostly piscivorous and zoobenthivores. Given the absence of regulation for bottom trawling activities in the area, the cumulative effects of trawling on population parameters, species composition, potentially decreasing the abundance of benthic preys (e.g., shrimps, worms and crabs) may lead to changes in the trophic structure potentially affect the food web and the sustainability of the fishery.
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Affiliation(s)
- Alex Souza Lira
- Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco, Brazil
- IRD, Univ Brest, CNRS, Ifremer, LEMAR, F-29280 Plouzané, France
- * E-mail:
| | - Flávia Lucena-Frédou
- Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco, Brazil
| | - Frédéric Ménard
- Aix Marseille Univ, Univ Toulon, CNRS, IRD, MIO, UM110, Marseille, France
| | - Thierry Frédou
- Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco, Brazil
| | - Júlio Guazzelli Gonzalez
- Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco, Brazil
- MARBEC, Univ. Montpellier, CNRS, IRD, Ifremer, 34095, Montpellier, France
| | - Valdimere Ferreira
- Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco (UFRPE), Recife, Pernambuco, Brazil
| | - José Souto Rosa Filho
- Departamento de Oceanografia, Laboratório de Bentos (LABEN), Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil
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Caruso G, Floris R, Serangeli C, Di Paola L. Fishery Wastes as a Yet Undiscovered Treasure from the Sea: Biomolecules Sources, Extraction Methods and Valorization. Mar Drugs 2020; 18:md18120622. [PMID: 33297310 PMCID: PMC7762275 DOI: 10.3390/md18120622] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/30/2020] [Accepted: 12/03/2020] [Indexed: 12/11/2022] Open
Abstract
The search for new biological sources of commercial value is a major goal for the sustainable management of natural resources. The huge amount of fishery by-catch or processing by-products continuously produced needs to be managed to avoid environmental problems and keep resource sustainability. Fishery by-products can represent an interesting source of high added value bioactive compounds, such as proteins, carbohydrates, collagen, polyunsaturated fatty acids, chitin, polyphenolic constituents, carotenoids, vitamins, alkaloids, tocopherols, tocotrienols, toxins; nevertheless, their biotechnological potential is still largely underutilized. Depending on their structural and functional characteristics, marine-derived biomolecules can find several applications in food industry, agriculture, biotechnological (chemical, industrial or environmental) fields. Fish internal organs are a rich and underexplored source of bioactive compounds; the fish gut microbiota biosynthesizes essential or short-chain fatty acids, vitamins, minerals or enzymes and is also a source of probiotic candidates, in turn producing bioactive compounds with antibiotic and biosurfactant/bioemulsifier activities. Chemical, enzymatic and/or microbial processing of fishery by-catch or processing by-products allows the production of different valuable bioactive compounds; to date, however, the lack of cost-effective extraction strategies so far has prevented their exploitation on a large scale. Standardization and optimization of extraction procedures are urgently required, as processing conditions can affect the qualitative and quantitative properties of these biomolecules. Valorization routes for such raw materials can provide a great additional value for companies involved in the field of bioprospecting. The present review aims at collecting current knowledge on fishery by-catch or by-products, exploring the valorization of their active biomolecules, in application of the circular economy paradigm applied to the fishery field. It will address specific issues from a biorefinery perspective: (i) fish tissues and organs as potential sources of metabolites, antibiotics and probiotics; (ii) screening for bioactive compounds; (iii) extraction processes and innovative technologies for purification and chemical characterization; (iv) energy production technologies for the exhausted biomass. We provide a general perspective on the techno-economic feasibility and the environmental footprint of the production process, as well as on the definition of legal constraints for the new products production and commercial use.
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Affiliation(s)
- Gabriella Caruso
- Institute of Polar Sciences, National Research Council, 98122 Messina, Italy
- Correspondence: ; Tel.: +39-090-6015-423
| | - Rosanna Floris
- AGRIS-Sardegna, Servizio Ricerca Prodotti Ittici, Bonassai, 07100 Sassari, Italy;
| | | | - Luisa Di Paola
- Unit of Chemical-Physics Fundamentals in Chemical Engineering, Department of Engineering, Università Campus Bio-Medico di Roma, 00128 Rome, Italy;
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Gilman E, Perez Roda A, Huntington T, Kennelly SJ, Suuronen P, Chaloupka M, Medley PAH. Benchmarking global fisheries discards. Sci Rep 2020; 10:14017. [PMID: 32820238 PMCID: PMC7441149 DOI: 10.1038/s41598-020-71021-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 08/10/2020] [Indexed: 11/09/2022] Open
Abstract
Discarding by fisheries is one of the most wasteful human marine activities, yet we have few estimates of its scale. Reliable estimates of global discards are essential for sustainable fisheries management. Using United Nations Food and Agriculture Organization databases on country-specific landings, we estimated the discard rate and magnitude for global marine and estuarine capture fisheries using fishery-specific discard rates derived from direct observations and global gear-specific discard rates estimated within a Bayesian modelling framework. An estimated 9.1 million tonnes are discarded annually (95% uncertainty interval: 7-16 M t)-or 10.8% of the global catch (95% UI: 10-12%). Encouragingly, this is about half of the annual global discard rate estimated in the late 1980s. Trawl fisheries, especially demersal otter trawls, warrant intensified efforts to reduce discards. Periodic benchmarks of global discards are needed to assess the performance of reduction efforts.
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Affiliation(s)
- E Gilman
- Pelagic Ecosystems Research Group, Honolulu, USA.
| | - A Perez Roda
- Food and Agriculture Organization of the United Nations, Rome, Italy
| | - T Huntington
- Poseidon Aquatic Resources Management Ltd., Lymington, UK
| | | | - P Suuronen
- Natural Resources Institute Finland, Helsinki, Finland
| | - M Chaloupka
- Ecological Modelling Services Pty Ltd and Marine Spatial Ecology Lab, University of Queensland, Brisbane, Australia
| | - P A H Medley
- Poseidon Aquatic Resources Management Ltd., Lymington, UK
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8
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Porobic J, Fulton EA, Parada C, Frusher S, Ernst B, Manríquez P. The impact of fishing on a highly vulnerable ecosystem, the case of Juan Fernández Ridge ecosystem. PLoS One 2019; 14:e0212485. [PMID: 30794609 PMCID: PMC6386342 DOI: 10.1371/journal.pone.0212485] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 02/03/2019] [Indexed: 12/01/2022] Open
Abstract
The Juan Fernández Ridge (JFRE) is a vulnerable marine ecosystem (VME) located off the coast of central Chile formed by the Juan Fernández Archipelago and a group of seamounts. This ecosystem has unique biological and oceanographic features, characterized by: small geographical units, high degree of endemism with a high degree of connectivity within the system. Two fleets have historically operated in this system: a long term coastal artisanal fishery associated with the Islands, focused mainly on lobster, and a mainland based industrial demersal finfish fishery operating on the seamounts which is currently considered overexploited. The management of these fisheries has been based on a classical single-species approach to determine output controls (industrial fleet) and a mixed management system with formal and informal components (artisanal fleet). There has been growing interest in increasing the exploitation of fisheries, and modernization of the fishing fleet already operating in the JFRE. Under this scenario of increased levels of fishing exploitation and the high level of interrelation of species it might be necessary to understand the impact of these fisheries from a holistic perspective based on a ecosystem-based modeling approach. To address these challenges we developed an Atlantis end-to-end model was configured for this ecosystem. The implemented model has a high degree of skill in representing the observed trends and fluctuations of the JFRE. The model shows that the industrial fishing has a localized impact and the artisanal fisheries have a relatively low impact on the ecosystem, mainly via the lobster fishery. The model indicates that the depletion of large sized lobster has leads to an increase in the population of sea urchins. Although this increase is not sufficient, as yet, to cause substantial flow-on effects to other groups, caution is advised in case extra pressure leads the ecosystem towards a regime shift.
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Affiliation(s)
- Javier Porobic
- Quantitative Marine Science Program, Institute for Marine and Antarctic Studies, Hobart, Tasmania, Australia
- CSIRO Oceans and Atmosphere, Hobart, Australia
- Institute for Marine and Antarctic Studies, University of Tasmania, Tasmania, Australia
- * E-mail:
| | - Elizabeth A. Fulton
- CSIRO Oceans and Atmosphere, Hobart, Australia
- Centre for Marine Socioecology, University of Tasmania, Tasmania, Australia
| | - Carolina Parada
- Departamento de Geofísica, Universidad de Concepción, Concepción, Chile
- Instituto Milenio de Oceanografía, Universidad de Concepción, Concepción, Chile
- Millennium Nucleus of Ecology and Sustainable Management of Oceanic Islands (ESMOI), Departamento Biología Marina, Universidad Católica del Norte, Coquimbo, Chile
| | - Stewart Frusher
- Centre for Marine Socioecology, University of Tasmania, Tasmania, Australia
| | - Billy Ernst
- Millennium Nucleus of Ecology and Sustainable Management of Oceanic Islands (ESMOI), Departamento Biología Marina, Universidad Católica del Norte, Coquimbo, Chile
- Departamento de Oceanografía, Universidad de Concepción, Concepción, Chile
| | - Pablo Manríquez
- Departamento de Oceanografía, Universidad de Concepción, Concepción, Chile
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A Review of the European Union Landing Obligation Focusing on Its Implications for Fisheries and the Environment. SUSTAINABILITY 2018. [DOI: 10.3390/su10040900] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Discarding is a common practice in fisheries. Total discards are estimated to be about 30 million tons, representing around 23% of worldwide catches. Discarding is an undesirable practice, not only because of the waste of resources, but also because of its contribution to the overexploitation of fish stocks. Several countries have already established discard bans, to different extents (e.g., Norway, Iceland, Chile, New Zealand). The EU’s landing obligation (discard ban) is a major measure of the latest reform of the Common Fisheries Policy for EU fisheries. It aims to reduce unwanted catches in EU fisheries, by incentivizing improved selectivity and restoring fish stocks to levels that can sustain the maximum production over time without harming the biodiversity and the capacity of future generations to obtain fish. However, banning discards will inevitably induce diverse short- and long-term ecological, economic, and social impacts, which may determine whether the landing obligation’s objectives will be achieved.
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10
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Collet J, Patrick SC, Weimerskirch H. A comparative analysis of the behavioral response to fishing boats in two albatross species. Behav Ecol 2017. [DOI: 10.1093/beheco/arx097] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Szostek CL, Murray LG, Bell E, Lambert G, Kaiser MJ. Regional variation in bycatches associated with king scallop (Pecten maximus L.) dredge fisheries. MARINE ENVIRONMENTAL RESEARCH 2017; 123:1-13. [PMID: 27846413 DOI: 10.1016/j.marenvres.2016.11.006] [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: 05/04/2016] [Revised: 11/08/2016] [Accepted: 11/08/2016] [Indexed: 06/06/2023]
Abstract
The biomass and composition of bycatch from king scallop dredge fisheries was assessed and compared between the English Channel, Cardigan Bay in Wales and around the Isle of Man. Bycatch composition varied significantly at localised, and broad, geographic scales. The mean proportion of scallop dredge bycatch biomass in the English Channel was 19% of total catch biomass. The proportion of bycatch was lower in Cardigan Bay (15%) but notably higher around the Isle of Man (53%). The proportion of individual bycatch species in dredge catches were low, therefore scallop dredging is unlikely to cause a substantial increase the population mortality of individual commercially fished species beyond that caused by the target fisheries for those species, or bycatches of other fisheries. The amount and mortality of organisms left on the seabed in the dredge path was not quantified in this study but should also be considered in management of the fishery. The discard rate of finfish and shellfish of commercial value from the king scallop dredge fishery in the English Channel was between 18 and 100%, with a higher rate of discarding occurring in the eastern English Channel compared to the west. The clear regional differences in bycatch composition and variation in the quantity of discards mean that an area by area approach to managing bycatch species is required in relation to the king scallop dredge fishery.
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Affiliation(s)
- Claire L Szostek
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK.
| | - Lee G Murray
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK
| | - Ewen Bell
- Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Pakefield Road, Lowestoft, Suffolk NR33 0HT, UK
| | - Gwladys Lambert
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK
| | - Michel J Kaiser
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK
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Vogel C, Kopp D, Méhault S. From discard ban to exemption: How can gear technology help reduce catches of undersized Nephrops and hake in the Bay of Biscay trawling fleet? JOURNAL OF ENVIRONMENTAL MANAGEMENT 2017; 186:96-107. [PMID: 27816227 DOI: 10.1016/j.jenvman.2016.10.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 09/24/2016] [Accepted: 10/12/2016] [Indexed: 06/06/2023]
Abstract
On January 1st, 2016, the French mixed Nephrops and hake fishery of the Grande Vasière, an area located in the Bay of Biscay, fell under the discard ban implemented as part of the new European Common Fisheries Policy. The fleet records historically high levels of discard despite numerous gear selectivity studies. Together with high discards survival, new technological solutions to minimize catches of undersized individuals could justify local exemptions from the discard ban. Our study focuses on the effects of two selective devices, a square mesh cylinder (SMC) and a grid, on the escapement of undersized individuals and discard reduction. Relative catch probability of the modified gear compared with the traditional gear was modelled using the catch comparison method. Potential losses from the commercial fraction of the catch were taken into account to assess their influence on the economic viability of fishing with the modified gears. The two devices had similar effects on undersized Nephrops escapement and on discard reduction, with median values of 26.5% and 23.6% for the SMC and of 30.4% and 21.4% for the grid, respectively. Only the grid was efficient for undersized hake, recording median values of escapement and discard reduction equal to 25.0% and 20.6%, respectively. Some loss from the commercial fraction of the catch was to be expected with both devices, which could be compensated for in the long term by the contribution of undersized individuals to the stock biomass. Our results support the use of selective gears technology as part of an integrated framework including control and management measures to mitigate the effect of the discard ban both for fishers and for the ecosystem. Further work is needed to quantify the effect of additional escapement from the gear on stock dynamics.
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Affiliation(s)
- Camille Vogel
- IFREMER, Department of Biological Resources and Environment, Fisheries Science and Technology Research Unit, Laboratory for Fisheries Technologies and Fish Biology (RBE/STH/LTBH), 8 rue François Toullec, F-56100 Lorient, France; IFREMER, Department of Biological Resources and Environment, Fisheries Science for the English Channel and North Sea, Fisheries Resources Laboratory (RBE/HMMN/RHPEB), Avenue du Général de Gaulle, F-14520 Port-en-Bessin-Huppain, France.
| | - Dorothée Kopp
- IFREMER, Department of Biological Resources and Environment, Fisheries Science and Technology Research Unit, Laboratory for Fisheries Technologies and Fish Biology (RBE/STH/LTBH), 8 rue François Toullec, F-56100 Lorient, France.
| | - Sonia Méhault
- IFREMER, Department of Biological Resources and Environment, Fisheries Science and Technology Research Unit, Laboratory for Fisheries Technologies and Fish Biology (RBE/STH/LTBH), 8 rue François Toullec, F-56100 Lorient, France.
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Murray MG. Partitioning ecosystems for sustainability. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:624-636. [PMID: 27209800 DOI: 10.1890/14-1156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Decline in the abundance of renewable natural resources (RNRs) coupled with increasing demands of an expanding human population will greatly intensify competition for Earth's natural resources during this century, yet curiously, analytical approaches to the management of productive ecosystems (ecological theory of wildlife harvesting, tragedy of the commons, green economics, and bioeconomics) give only peripheral attention to the driving influence of competition on resource exploitation. Here, I apply resource competition theory (RCT) to the exploitation of RNRs and derive four general policies in support of their sustainable and equitable use: (1) regulate resource extraction technology to avoid damage to the resource base; (2) increase efficiency of resource use and reduce waste at every step in the resource supply chain and distribution network; (3) partition ecosystems with the harvesting niche as the basic organizing principle for sustainable management of natural resources by multiple users; and (4) increase negative feedback between consumer and resource to bring about long-term sustainable use. A simple policy framework demonstrates how RCT integrates with other elements of sustainability science to better manage productive ecosystems. Several problem areas of RNR management are discussed in the light of RCT, including tragedy of the commons, overharvesting, resource collapse, bycatch, single species quotas, and simplification of ecosystems.
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14
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Temporal and age-related dietary variations in a large population of yellow-legged gulls Larus michahellis: implications for management and conservation. EUR J WILDLIFE RES 2015. [DOI: 10.1007/s10344-015-0958-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Heath MR, Cook RM. Hind-casting the quantity and composition of discards by mixed demersal fisheries in the North Sea. PLoS One 2015; 10:e0117078. [PMID: 25774938 PMCID: PMC4361349 DOI: 10.1371/journal.pone.0117078] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 12/14/2014] [Indexed: 11/18/2022] Open
Abstract
Many commercial fisheries seek to maximise the economic value of the catch that they bring ashore and market for human consumption by discarding undersize or low value fish. Information on the quantity, size and species composition of discarded fish is vital for stock assessments and for devising legislation to minimise the practice. However, except for a few major species, data are usually extremely sparse and reliant on observers aboard a small sample of fishing vessels. Expanding these data to estimate total regional discards is highly problematic. Here, we develop a method for utilising additional information from scientific trawl surveys to model the quantities of fish discarded by the commercial fisheries. As a case-study, we apply the model to the North Sea over the period 1978-2011, and show a long-term decline in the overall quantity of fish discarded, but an increase in the proportion of catch which is thrown away. The composition of discarded catch has shifted from predominantly (∼80%) roundfish, to >50% flatfish. Undersized plaice constitute the largest single fraction of discards, unchanged from the beginning of the 20th century. Overall, around 60% of discarded fish are rejected on the basis of size rather than for reasons of species value or quota restrictions. The analysis shows that much more information can be gained on discarding by utilising additional sources of data rather than relying solely on information gathered by observers. In addition, it is clear that reducing fishing intensity and rebuilding stocks is likely to be more effective at reducing discards in the long term, than any technical legislation to outlaw the practice in the short term.
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Affiliation(s)
- Michael R. Heath
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, Scotland, United Kingdom
| | - Robin M. Cook
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, Scotland, United Kingdom
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