June 2024

During the period 1998-2001, a survey to study the incidence of the drifting longline fishery on shark populations was carried out in the eastern Mediterranean Sea. A total of 8 different pelagic shark species were recorded in the catches of the Greek swordfish and albacore longline fisheries. Among them, the blue shark, Prionace glauca, was […]

Direct interactions between longline fisheries and many top predators such as toothed whales result in substatial impacts on fishing activity; depredating species and fish stocks. These issues continue to be a growing concern in fisheries worldwide, including the French Patagonian toothfish fishery. In this field study, researchers deployed data loggers on killer whales and sperm […]

A mechanical separating bycatch reduction device was tested in the Spencer Gulf king prawn trawl fishery to reduce the incidental capture of giant cuttlefish (Sepia apama) and blue swimmer crabs (Portunus armatus). Different sizes of Nordmore grids were tested. Two Nordmore grids were inserted into the posterior extension sections and triangular escape exits were cut […]

The authors investigated the effects of a large-scale gillnet closure on sea bird populations in Canadian waters. After a 1992 closure, breeding populations of bycatch-prone diving birds (auks and gannets) increased, with a corresponding decrease in surface-feeding scavengers such as gulls that are less prone to bycatch in gillnets but that do consume fisheries discards.

Sharks, turtles, billfish, and marine mammals are frequently caught accidentally in commercial fisheries. Although conservationists and fisheries managers encourage the release of these nontarget species, the long-term outcome of released animals is uncertain. Using blue sharks (Prionace glauca), we developed a model to predict the long-term survival of released animals based on analysis of small […]

Experiments were carried out aboard vessels in the Danish North Sea hake gillnet fishery to determine if increasing the spacing of Aqutec AQUAmark100 pingers could be done without negatively impacting the effectiveness of the pinger. Control nets without pingers were tested alongside nets with pingers spaced at 455 m and 585 m. The control nets […]

Studies were conducted aboard beam trawlers in the North Sea to determine the performance of pulse beam compared to conventional tickler chain beam trawlers.  Overall the pulse beam trawl caught 68% less than the conventional trawls.  Specifically, the pulse beam trawl caught significantly fewer plaice and sole compared to the conventional beam trawl. There was no […]

Blue sharks account for most of the bycatch in the Canadian pelagic longline swordfish fishery. Electropositive metals (e.g. lanthanide) oxidize in seawater and create electric fields, which can alter the behaviors of several species of sharks. Researchers deployed seven sets (6300 hooks) with three hook treatments (standard hooks, hooks with electropositive metals – neodymium/praseodymium – […]

Right whale survey data and Canadian fishing gear deployment data were used to estimate the threat of gear entanglement to right whales in the Scotia-Fundy region and the risk of lethal entanglement in the Bay of Fundy and Roseway Basin, Scotian Shelf. The following fisheries were investigated: groundfish and pelagic hook and line, groundfish gillnet, […]

Integrated weight longlines (IW) were tested for their ability to reduce sea bird bycatch in demersal longline fisheries. The target fishery for testing was the Pacific cod fishery operating in the Bering Sea, Alaska, USA. Three experimental mitigation techniques were tested: 1) IW line alone, 2) IW paired with streamer lines (IWPS) and 3) unweighted […]

The impact of Medina panels attached to tuna purse seine nets operating in the US fishery was investigating for their effect on porpoise mortality. Medina panels are reduced mesh size netting hung from 2-inch mesh webbing on the purse seine. The authors took measurements of penetration of porpoise snouts and flippers through mesh openings of […]

A study was conducted in Sundarbans mangrove forest of Bangladesh to assess the behavioral response of Ganges River dolphins to pingers. Just under 62 hours of theodolite tracking data from 75 dolphin sightings and 2,829 theodolite fixes of dolphin surfacing were analyzed. The results suggest pingers had a subtle displacement effect on the dolphins. There […]

Type Species Distribution Population Bycatch Threat IUCN Status Leatherback Turtle Reptile Dermochelys coriacea Circumglobal in tropical to sub-polar waters Decreasing Longlines, gillnets, trawls, pot/traps Critically Endangered Loggerhead Turtle Reptile Caretta caretta Circumglobal, in tropical and subtropical waters Unknown Longlines, gillnets, trawls, traps and pots, and dredges Globally Endangered Australian sea lion Mammal Neophoca cinerea Southern […]

A structured literature review of 103 papers was conducted to characterize trends in shark bycatch research.  Gear modifications, such as hook size/type and net size, were the most commonly evaluated technique to reduce shark bycatch.  Early studies tended to focus on trawl fisheries while more current studies focus on longline fisheries, particularly tuna fisheries. Overall, […]