Search The Database

This study assessed the interaction of leatherback sea turtles (Dermochelys coriacea) with fixed-gear fisheries in high-latitude seasonal foraging habitat (Atlantic Canada), using sightings data from 1998-2014. Most reports came from coastal Nova Scotia and Newfoundland, with reports peaking in the mid-to-late 2000s. The majority of reported entanglements came during the summer months (July and August), and were with pot gear and trap nets. 

Bycatch reduction devices (BRDs) allow selective release of unwanted fish (bycatch) during fishing operations, while retaining target fish. Existing BRDs use passive methods, exploiting differences in fish behavior, size, and/or shape to separate bycatch from target species. Recent availability of practical systems transmitting real-time video from trawls to the towing vessel during routine fishing opens the possibility to develop active selection (ActSel) BRDs, devices that allow trawlers to selectively trigger fish release when bycatch species are observed.
Development through numerical modeling, scale-model tests, and full-scale, at-sea trials, resulted in an ActSel BRD system that, when triggered, quickly (average 10 s) and reversibly moved a mesh panel between configurations covering a release opening or leading fish out of that opening. A hydrodynamic kite across that selection panel’s leading edge drove it between catch and release positions. Manipulation of control lines by a remotely-controlled electromechanical reel adjusted the kite’s orientation, determining movements of the mesh panel. Results of full-scale testing of this ActSel system under commercial fishing conditions while trawling for Pacific hake (Merluccius productus) showed that ActSel operation effectively and reversibly changed movement of all fish from normal passage toward the codend to moving toward the release opening. While our sea trials occurred in the Pacific hake fishery, the ActSel has applications to other trawl fisheries, particularly fisheries where real-time video systems are used (i.e., Alaska pollock (Gadus chalcogrammus) fishery).

This study examined the effects of different tail-section towing configurations on tori line aerial-extent performance using at-sea trials on Chinese tuna-fishing vessels. Three tori line configurations were evaluated at representative operational vessel speeds of 4.5, 6.0, and 8.2 kt. These included the baseline streamer configuration, a plastic-cone configuration (20 m long drag section with four 45 cm plastic cones installed at intervals of 2 m), and a drogue configuration (20 m long drag section with 50 cm drogue at terminal end, followed by 10 m of resin rope and a 200 mm float). A sensitivity analysis was also conducted using low-, moderate-, and high-drag scenarios, and the drag force generated by each configuration was estimated. The results showed that tail-section towing configuration clearly affected the aerial deployment of the tori line. The drogue configuration achieved the best aerial-extent performance at all tested vessel speeds, and met or exceeded the 100 m benchmark under all test conditions. The baseline streamer configuration ranked second. These findings indicate that both the magnitude and stability of the drag generated by the tail-section towing configuration are important factors influencing tori line aerial-extent performance.

A cumulative impact analysis framework integrating species habitat suitability and fishing effort data, stratified by gear type, was used to assess bycatch risk for threatened and protected species in China's seas and adjacent waters. Across all taxonomic groups examined, including seabirds, sea turtles, marine mammals, elasmobranchs, bony fishes, and benthic invertebrates, the highest bycatch risk was concentrated between 23°N and 25°N. For marine mammals and sea turtles, elevated risk was concentrated along China's southeastern coast, extending through inshore waters from the Yangtze River Estuary south to 20°N, with trawls and gillnets contributing most significantly to risk. Seabird bycatch hotspots were primarily located around islands, bays, and estuaries north of 20°N, where gillnets posed the greatest threat. Elasmobranchs experienced high bycatch risk from the Taiwan Strait to the Yangtze River Estuary and around Jeju Island, and were the most vulnerable taxa group overall. Bycatch risk for benthic invertebrates was largely restricted to narrow nearshore areas and was associated primarily with dredging activities. The study also found that marine protected areas generally exhibited lower bycatch risk than surrounding waters.

A structured narrative review of the impact of artificial light on catch performance was conducted using peer-reviewed literature published mainly during 2016–2025, emphasizing field experiments and physiological studies relevant to light-assisted capture. Blue, cyan, and green wavelengths frequently produced strong behavioral or catch responses because they propagate efficiently in seawater and overlap with the visual sensitivity of many marine organisms. However, outcomes were strongly dependent on species, fishing gear, irradiance, depth, water optical properties, and operational context. Light may also indirectly influence catch by attracting prey organisms or altering bycatch interactions. 

This study quantified spatial overlap between seabirds and industrial and small-scale coastal longline fisheries in the eastern Pacific Ocean, as well as overlap between seabird utilization distributions and areas where seabird bycatch mitigation is mandated by the Inter-American Tropical Tuna Commission (IATTC). Species with the highest overlap with fisheries, a proxy for bycatch risk, included non-breeding adult black (Procellaria parkinsoni) and white-chinned petrels (P. aequinoctialis), Chatham (Thalassarche eremita), Buller’s (T. bulleri), Antipodean (Diomedea antipodensis antipodensis), and Salvin’s (T. salvini) albatrosses, and breeding waved albatrosses (Phoebastria irrorata). The IATTC mitigation area appeared to encompass most core habitat in the eastern Pacific for the seabird species considered, with the notable exception of foraging black petrels, which largely occurred outside this area. 

This study investigated spatiotemporal patterns in harbor porpoise (Phocoena phocoena) bycatch rates in the Swedish gillnet fishery, including a first assessment of harbor porpoise bycatch along the Swedish south coast. Bycatch rates were higher along the southern than the western coast. Further, porpoise bycatch in the south likely is from the endangered Belt Sea subpopulation, rather than the critically endangered Baltic Sea subpopulation. The estimates also indicate a declining trend in the number of bycaught individuals, likely reflecting reduced gillnet fishing effort over time.

This study evaluated the efficacy of two above-water deterrents - "scarybird" kites and looming-eyes buoys- in reducing seabird bycatch in gillnet fisheries in the United Kingdom. Both deterrents significantly reduced the chance and magnitude of auk (Family Alcidae) bycatch relative to controls. Kites had a stronger deterrent effect closer to the device, while looming-eye buoys were effective over a broader range. However, above-water deterrents did not appear to impact bycatch of other species, including cetaceans and seals.

An accordion-shaped shrimp trap, called Bubu Naga, is increasingly being used by fishers targeting white shrimp (Penaeus meguiensis) in Tambak Lorok, Indonesia. Data from six fishing trips in November 2024 was analyzed using criteria from the FAO Code of Conduct for Responsible Fisheries (CCRF). 42% of catch were target species, while 58% was considered bycatch, meaning that it does not meet CCRF targets for environmental selectivity. In addition, only 24% of catch met size targets. However, the trap scores high on other criteria, including low potential to damage habitat or endanger fishers or consumers. Additional work to refine the selectivity of the trap could be undertaken to further improve its environmental performance. 

This study evaluated the effectiveness of two seal excluder devices, the Danish Pelagic Producers Organization (DPPO)'s excluder tube and the Pelagic Freezer Trawler Association (PFA)'s excluder gird in reducing seal capture in sandeel (Ammodytes marinus) and herring (Clupea harengus) fisheries. Voluntary, operational-level industry self-reporting on the excluder devices found a 85% reduction of seal capture in the sandeel fishery and an 89% reduction in the herring fishery (with some uncertainty around the estimates, particularly in the herring fishery).