maximios

In the Indian Ocean tuna gillnet fisheries, cetacean bycatch is very high, but it is understudied and poorly understood. This paper investigates the issue and makes specific recommendations to strengthen knowledge and management: improve catch and bycatch reporting, increase research and analyses of cetaceans in the region in order to assess bycatch, revise the conservation […]

A meta-analysis of online publications revealed only one technique to be effective as a bycatch reduction device in longline fisheries, which involves raising demersal longlines off the seafloor using flotation. Other techniques as BRDs include monofilament leaders which, like floating demersal longlines, are suggested as promising approaches for further evaluation. Although not effective as a […]

Field experiments were conducted to determine behavioral responses of minke whales to experimental ropes and buoys made up of different colors, simulating those used in crab and whelk fishing gear. Trials were conducted with yellow, orange, green, blue, white and black ropes. Visual and acoustic monitoring was used to assess behavioral responses of whales to […]

Entanglement in commercial fishing ropes threatens the recovery of the North Atlantic right whale (Eubalaena glacialis), a species largely restricted to waters off of eastern North America. In recent years, serious entanglements have been increasing, and mortality from conflicts with fishing operations exceeds US legal mandates, with 83% of the population showing incidence of scarring […]

Passive acoustic deterrents in the form of chains of metallic beads and air-filled plastic tubing attached to gillnets in Australia did not reduce bycatch of two small cetaceans: the Atlantic bottlenose dolphin (Tursiops truncatus) and Spinner dolphin (Stenella longiristris). A sub-surface set gillnet (set 4.5 m below the surface) in Australia reduced cetacean catch rate […]

Side-setting in combination with a bird curtain resulted in the lowest seabird– Black-footed albatross (Phoebastria nigripes) and Laysan albatross (Phoebastria immutabilis)–capture rate when placed on pelagic longline gear for tuna and swordfish in Hawaiian waters when compared to underwater setting chutes and blue-dyed bait.

Pelagic longlines were weighted with lead weights, enabling them to fish deeper in the water column than traditional pelagic longlines.  Weighted longlines caught 31 target species with a slightly higher catch per unit effort (CPUE) of 1.3 fish/100 hooks (49 kg/100 hooks) compared to traditional gear (38 target species and a CPUE of 1.08 fish/100 […]

A questionaire administered to the bottom trawling fleet in the western Mediterranean (northeastern Spain) reported 238 bycacth events involving loggerhead sea turtles (Caretta caretta), calculated as a monthly CPUE of .09. The authors dicuss this figure relative to nearby coastal regions and suggest some possible mitigation measures.

An alternative leader design reduced loggerhead (Caretta caretta) sea turtle interactions in a Chesapeake Bay pound net fishery for finfish. There was no change in catch of weakfish (Cynoscion regalis), croaker (Micropogonias undulates), and harvestfish (Peprilus alepidotus).

Fisheries bycatch is the principal threat to many marine mammals. In some cases, bycatch reduction devices have been shown to mitigate the bycatch of non-target species, but the scale of the problem outpaces progress in finding solutions. In particular, bycatch in coastal gillnet fisheries is one of the most immediate threats facing many marine mammal […]

In 2015, New England Aquarium researchers and collaborators published a paper in Conservation Biology titled Effects of fishing rope strength on the severity of large whale entanglements correlating rope strength with increased risk and severity of large whale entanglements (Knowlton et al. 2016). As a result of that study, the authors recommended that rope strengths […]

Demersal trawl gear used to catch Greenland halibut (Reinhardtius hippoglossoides) in west Greenland. A towed vide sled recorded trawling impacts on seafloor fauna. Trawling effort was significantly linked with community composition, with a negative association between trawling effort and abundance of some taxa, including some vulnerable marine ecosystem (VME) indicator species, including a regionally rare […]

Experiments were conducted aboard pelagic longline vessels off the east coast of Australia to determine the effects of different bait species (blue mackerel, yellow tail mackerel and squid), live and dead bait, weight of leaded swivels (60 g, 100 g and 160 g) and leader length (2 m, 3 m and 4 m distances between […]

Experimental trials were carried out in Argentina comparing franciscana bycatch rates in standard gillnets with gillnets with increased acoustic reglectivity by infusion with barium sulphate (BaSO4) and increased flexural stiffness of the nylon twine. There was no significant difference in franciscana bycatch rates or target catch rates among the three net types.