Search The Database
| Location | Gear | Catch | Technique | Bycatch species | Type | Results |
|---|---|---|---|---|---|---|
Sechura Bay, Peru |
Gillnets and Entangling Nets
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fish: (Paralichtys spp.), guitarfish (Rhinobatos planiceps), rays (superorder Batoidea |
Visual deterrents
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Seabirds | Field study in the wild | The authors tested the effectiveness of using green light emitting diodes (LEDs) on demeral, set gillnets in Constante, Peru as a visual deterrent to reduce seabird bycatch. When comparing illuminated nets to control nets, seabird bycatch was significantly lower and represented an 85.1% decline in guanay cormorant ((Phalacrocorax bougainvillii) bycatch. Target catch was not affected, suggesting that this mitigation technique may be an effective mitigation method for seabirds, the same way it seems to be effective for reducing sea turtle bycatch. significant reduction (85.1% for guanay cormorants (Phalacrocorax bougainvillii)) |
Berlengas Islands, Portugal |
Gillnets and Entangling Nets
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Multi-species, including hake (Merluccius merluccius), anglerfish (Lophius pescatorius), rays (Raja clavata, Raja brachyura), and sole (Solea solea) |
Visual deterrents
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Seabirds, Larus fuscus (Lesser black-backed gull), Larus michahellis (Yellow-legged gull), Morus bassanus (Northern gannet) | Field study in the wild | The authors tested the effectiveness of 'scarybird', a visual deterrent, to reduce seabird bycatch in bottom gillnet fisheries in Portugal. The scarybird is a raptor-shaped aerial device that is flown behind the stern of the boat up to ~7m above sea level. The scarybird successfully detered seabirds during fishing operations, especially within the closest 20m from the vessel, where there was a significant reduction in yellow-legged and lesser black-backed gull (Larus michahellis and L. fuscus, −56 %) and northern gannets (Morus bassanus, −72 %). Target catch was not affected, suggesting this mitigation measure could be an easily implementable device for any fishery gears where bird interactions occur close to the surface.
Significant reduction, especially for gulls and northern gannets within 20m of the vessel |
| Summary study | This paper suggests guidelines for evaluating artificial light in bycatch reduction devices (BRL) using a standardized, collaborative, multidisciplinary approach. The purpose is to improve data consistence to support future meta-analyses and inter-study comparisons, and to highlight areas where further research is needed most urgently, as BRLs are a promising and rapidly moving area of bycatch mitigation.
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| Summary study | This paper provides guidelines to create POAs (plan of action) in response to the issue of ALDFG (abandoned, lost, and discarded fishing gear) worldwide across varying gear types , fishery scales, and management. These Action Plans are designed to assist fishery stakeholders in preparing to meet the more rigorous Marine Stewardship Council standards for ALDFG and ghost fishing.
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| Summary study | The authors modeled 28 years of data to estimate the impact of entanglement on female North Atlantic right whale health, survival and reproduction. Results show that entangled whales were drastically more likely to experience negative health impacts, including declines in body condition and lower survival rates. Furthermore, whales in poor body condition were not reproductive- between 1994 and 2021, entanglements reduced the expected number of calves by 12.9% and the number of living females by 18.5%. The authors state that reducing entanglement risk is crucial in order for the population to recover.
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N/A |
Tuna, tuna-like species | Summary study | This letter briefly outlines actions taken by the five tuna regional fisheries management organizations (RFMOs) to reduce sea turtle bycatch in tuna and tuna-like fisheries. Recent initiatives include impact assessments, bycatch mitigation measures for pelagic fisheries, identification of sea turtle bycatch patterns in longline and perse seine tuna fisheries, and a joint tuna RFMO Bycatch Working Group meeting that took place in December 2019.
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| Summary study |
The authors analyzed data regarding shark bycatch in western & central Pacific longline fisheries from 2013-2021, and the influence of environmental and spatial factors. Results suggest that several environmental factors- including oxygen concentration, sea surface temperature, and chlorophyll-a concentration- impact shark bycatch per unit effort (BPUE) for multiple shark species. Hotstops of bycatch were identified for bigeye thresher shark (Alopias superciliosus), longfin mako (Isurus paucus), silky shark (Carcharhinus falciformis), oceanic whitetip shark (Carcharhinus longimanus), blue shark (Prionace glauca) and shortfin mako (sIsurus oxyrinchus). All species exhibited annual variations in BPUE, and bycatch risk trended eastward toward equatorial waters, likely due to a higher concentration of fishing effort in those areas.
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| Summary study | The authors compiled fishing effort data from a nearly 20 year period across 18 different longline, gillnet and purse seine fisheries in the eastern Pacific Ocean in order to assess/model vulnerability of leatherback sea turtles to fishing impacts under 70 different conservation management measure (CMM) scenarios. To do this, a new ecological risk assessment approach, the Ecological Assessment for the Sustainable Impacts of Fisheries (EASI-Fish), was used. The CMMs of large circle hooks, finfish bait, and best handling and release practices each decreased vulnerability, but the most effective scenarios used all three measures together. EASI-phish was used as the ecological risk assessment.
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| Summary study | This paper reports on an unusual mortality event (UME) of healthy, nourished, male Baltic grey seals (Halichoerus grypus grypus) that occurred in the Greifswald Bay at the German Baltic coast in autumn 2017. Findings suggest that the cause of death was bycatch in a fyke net, despite the grey seals being a legally protected species. As a result, the fisheries authority ultimately established precautionary provisions, and fyke nets in Greifswald Bay are now (since 2020) required to have an entrance opening size of no greater than 75cm in circumference, which seems to have been effective to prevent gray seal bycatch in the area. However, gray seal bycatch in other areas continues, suggesting the need for more widespread adoption of preventative provisions.
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| Study in the lab | This study investigates the mechanical performance of biodegradable fishing nets made from poly(butylene succinate-co-adipate-co-terephthalate) (PBSAT) as compared to conventional polyamide 6 (PA6) nets, in order to address ghost fishing and microplastic pollution by developing fishing gear that degrades in marine environments without compromising mechanical efficiency. Results show that PBSAT nets are weaker than PA6 nets in each component- monofilament, knots, and net. PBSAT nets biodegrade more easily, but do not match the current mechanical properties for commercial fishing. |