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Rouxel Y, Arnardóttir H, Oppel S. Looming-eyes buoys fail to reduce seabird bycatch in the Icelandic lumpfish fishery: depth-based fishing restrictions are an alternative. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230783. [PMID: 37885979 PMCID: PMC10598418 DOI: 10.1098/rsos.230783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/10/2023] [Indexed: 10/28/2023]
Abstract
Bycatch in gillnets from lumpfish (Cyclopterus lumpus) fisheries is an important conservation issue in the north Atlantic, with up to 30 000 seabirds potentially killed each year. To date, no technical solutions exist to reduce the bycatch of seabirds in gillnet fisheries, but research on above-water bird deterrents as a form of bycatch mitigation has shown promising results. Here, we tested whether a floating device called 'looming-eyes buoy' (LEB) would consistently reduce the bycatch of seabirds in the Icelandic lumpfish fishery. We conducted 61 controlled trials with sets of normal gillnets and experimental nets equipped with LEBs. We compared both fish catch and bycatch between net types while accounting for exposure time, water depth and season, and found no effect of LEBs on both target lumpfish catch and bycatch. Our analysis indicated however a strong correlation between bycatch rates and fishing depths, suggesting that depth-based fishing restrictions could virtually eliminate the bycatch of seabirds in this fishery. We estimated that limiting fishing to waters more than 50 m deep could save between 5000 and 9300 seabirds every year, arrest the population decline of endangered black guillemots in Iceland, while having only a marginal effect on target fish catch.
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Affiliation(s)
- Yann Rouxel
- BirdLife International Marine Programme, the Royal Society for the Protection of Birds Scotland, Glasgow, UK
| | | | - Steffen Oppel
- RSPB Centre for Conservation Science, Royal Society for the Protection of Birds, The Lodge, Sandy, UK
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Lively JA, McKenzie J. Discards and bycatch: A review of wasted fishing. ADVANCES IN MARINE BIOLOGY 2023; 95:1-26. [PMID: 37923537 DOI: 10.1016/bs.amb.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
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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Christensen-Dalsgaard S, Ytrehus B, Langset M, Wiig JR, Bærum KM. Seabird beachcast events associated with bycatch in the Norwegian purse seine fishery. MARINE ENVIRONMENTAL RESEARCH 2022; 177:105625. [PMID: 35462230 DOI: 10.1016/j.marenvres.2022.105625] [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: 12/14/2021] [Revised: 04/05/2022] [Accepted: 04/09/2022] [Indexed: 06/14/2023]
Abstract
Beachcast events, where a large number of seabird carcasses drift ashore, occur with irregular intervals. These events are due to specific situations where mass mortality of seabirds have occurred. Disentangling the cause of these events can provide valuable information on stressors impacting seabird populations. Following several mass mortality events involving gulls in northern Norway, an investigation of the probable cause of death was initiated. In total 75 dead gulls were collected at two occasions and necropsies were carried out. The findings from the necropsy of the gulls were consistent with drowning as the primary cause of death. Bycatch in coastal purse seine fishery was considered a potential cause of the mortality and monitoring of seabird bycatch in this fishery was thus initiated. The monitoring of fishing operations revealed that 10% of 91 fishing events observed led to bycatch, with a total of 32 bycaught seabirds. These bycatch events resulted in a total estimated bycatch rate of 0.356 (95% CI = 0.133-0.949) birds per haul. These findings are consistent with the hypothesis that the registered mortality events were caused by bycatch in the purse seine fishery. The highly episodic and unpredictable nature of these events makes it demanding to achieve solid estimates of the occurrence and extent of bycatch without a very high monitoring effort. Our study shows that systematic investigation following beachcast events can shed light on the occurrence of such extreme events.
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Affiliation(s)
| | - Bjørnar Ytrehus
- Norwegian Institute for Nature Research (NINA), P.O. Box PO 5685 Torgarden, 7485, Trondheim, Norway; Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences (SLU), SE-75007,Uppsala, Sweden
| | - Magdalene Langset
- Norwegian Institute for Nature Research (NINA), P.O. Box PO 5685 Torgarden, 7485, Trondheim, Norway
| | - Jørgen Ree Wiig
- Directorate of Fisheries, Sea Surveillance Unit, P.O. Box 185 Sentrum, 5804, Bergen, Norway
| | - Kim Magnus Bærum
- Norwegian Institute for Nature Research (NINA), Vormstuguvegen 40, 2624, Lillehammer, Norway
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Bertram DF, Wilson L, Charleton K, Hedd A, Robertson GJ, Smith JL, Morgan KH, Song XJ. Modelling entanglement rates to estimate mortality of marine birds in British Columbia commercial salmon gillnet fisheries. MARINE ENVIRONMENTAL RESEARCH 2021; 166:105268. [PMID: 33626460 DOI: 10.1016/j.marenvres.2021.105268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 01/25/2021] [Accepted: 01/29/2021] [Indexed: 06/12/2023]
Abstract
Incidental mortality of marine birds in fisheries is an international conservation concern, including in Canada where globally significant populations of vulnerable diving species overlap with coastal gillnet fisheries. In British Columbia (BC), commercial salmon gillnet fishing effort was historically very high (>200,000 days fished annually in the early 1950's), and although this fishery has declined, over 6,400 days were fished annually in the 2006-2016 decade. Observations of seabird bycatch within the commercial fishery, however, are limited in both scope (comprising <2% of cumulative effort 2001-2016) and in time (being available only from 1995 onwards and only for a small number of areas). Using onboard fishery observer data from commercial, test and experimental fisheries (1995-2016), we developed two models to estimate the number of marine birds captured per set in sockeye (Oncorhynchus nerka) and chum (O. keta) salmon gillnet fisheries employing a Generalized Linear Mixed Modeling (GLMM) approach in a hierarchical Bayesian framework, with observer data post-stratified by fisheries management area and year. Using estimates of total commercial fishing effort (estimated number of sets, 2001-2016) we applied the models to extrapolate annual take for the main bird species (or groups) of interest. Multinomial probability estimates of species composition were calculated based upon a sample of 852 birds identified to species that were associated with sockeye or chum fisheries, enabling estimates (with CIs) of potential numbers of the mostly commonly observed species (common murres (Uria aalge), rhinoceros auklets (Cerorhinca monocerata), and marbled murrelets (Brachyramphus marmoratus)) entangled annually in commercial sockeye and chum salmon gillnet fisheries throughout BC. Conservative estimates of annual losses to entanglement were greatest for common murres (2,846, 95% CI: 2,628-3,047), followed by rhinoceros auklets (641, CI: 549-770) and marbled murrelets (228 CI: 156-346). Populations of all three of these alcids species are currently in decline in BC and entanglement mortality is a conservation concern. Gillnet mortality has been identified as a longstanding threat to marbled murrelet populations, which are recognized as Threatened in the Canada and the United States of America (USA). In addition, 622 (CI: 458-827) birds from 12 other species were estimated to be entangled annually. We conclude that cumulative mortality from incidental take in salmon gillnet fisheries is one of the largest sources of human-induced mortality for marine birds in BC waters, a conservation concern impacting both breeders and visiting migrants.
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Affiliation(s)
- Douglas F Bertram
- Environment and Climate Change Canada, PO Box 6000, Sidney, BC, V8L 4B2, Canada.
| | - Laurie Wilson
- Environment and Climate Change Canada, 5421 Robertson Rd. RR1, Delta, BC, V4K 3N2, Canada
| | | | - April Hedd
- Environment and Climate Change Canada, 6 Bruce Street, Mount Pearl, NL, A1N 4T3, Canada
| | - Gregory J Robertson
- Environment and Climate Change Canada, 6 Bruce Street, Mount Pearl, NL, A1N 4T3, Canada
| | - Joanna L Smith
- Nature United, 366 Adelaide St. East, Suite 331, Toronto, ON, M5A 3X9, Canada
| | - Ken H Morgan
- Environment and Climate Change Canada, PO Box 6000, Sidney, BC, V8L 4B2, Canada
| | - Xiao J Song
- 319A Evergreen Dr, Port Moody, BC, V5E 2A4, Canada
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Verutes GM, Johnson AF, Caillat M, Ponnampalam LS, Peter C, Vu L, Junchompoo C, Lewison RL, Hines EM. Using GIS and stakeholder involvement to innovate marine mammal bycatch risk assessment in data-limited fisheries. PLoS One 2020; 15:e0237835. [PMID: 32817725 PMCID: PMC7446845 DOI: 10.1371/journal.pone.0237835] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 08/04/2020] [Indexed: 11/25/2022] Open
Abstract
Fisheries bycatch has been identified as the greatest threat to marine mammals worldwide. Characterizing the impacts of bycatch on marine mammals is challenging because it is difficult to both observe and quantify, particularly in small-scale fisheries where data on fishing effort and marine mammal abundance and distribution are often limited. The lack of risk frameworks that can integrate and visualize existing data have hindered the ability to describe and quantify bycatch risk. Here, we describe the design of a new geographic information systems tool built specifically for the analysis of bycatch in small-scale fisheries, called Bycatch Risk Assessment (ByRA). Using marine mammals in Malaysia and Vietnam as a test case, we applied ByRA to assess the risks posed to Irrawaddy dolphins (Orcaella brevirostris) and dugongs (Dugong dugon) by five small-scale fishing gear types (hook and line, nets, longlines, pots and traps, and trawls). ByRA leverages existing data on animal distributions, fisheries effort, and estimates of interaction rates by combining expert knowledge and spatial analyses of existing data to visualize and characterize bycatch risk. By identifying areas of bycatch concern while accounting for uncertainty using graphics, maps and summary tables, we demonstrate the importance of integrating available geospatial data in an accessible format that taps into local knowledge and can be corroborated by and communicated to stakeholders of data-limited fisheries. Our methodological approach aims to meet a critical need of fisheries managers: to identify emergent interaction patterns between fishing gears and marine mammals and support the development of management actions that can lead to sustainable fisheries and mitigate bycatch risk for species of conservation concern.
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Affiliation(s)
- Gregory M. Verutes
- Faculty of Political and Social Sciences, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
- Campus Do*Mar, International Campus of Excellence, Vigo, Spain
- * E-mail:
| | - Andrew F. Johnson
- MarFishEco Fisheries Consultants, Edinburgh, United Kingdom
- The Lyell Centre, Institute of Life and Earth Sciences, School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh, United Kingdom
| | | | | | - Cindy Peter
- Institute of Biodiversity and Environmental Conservation, University Malaysia Sarawak, Sarawak, Malaysia
| | - Long Vu
- Vietnam Marine Megafauna Network, Center for Biodiversity Conservation and Endangered Species, Ho Chi Minh, Vietnam
| | | | - Rebecca L. Lewison
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | - Ellen M. Hines
- Estuary & Ocean Science Center, San Francisco State University, Tiburon, CA, United States of America
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Landa A, Guidos S. Bycatch in local fishery disrupts natural reestablishment of Eurasian otter in western Norway. CONSERVATION SCIENCE AND PRACTICE 2020. [DOI: 10.1111/csp2.208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Arild Landa
- Norwegian Institute for Nature Research Bergen Norway
| | - Steven Guidos
- Norwegian Institute for Nature Research Bergen Norway
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