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Summary: Deep water setting techniques, tested on longline gear in Hawaii, reduced bycatch of sea turtles and striped marlin. Bycatch of target species, bigeye tuna, increased 1.27 times.

Summary: To reduce turtle interactions, regulations for the Hawaii-based longline swordfish fishery required vessels to switch from using a J-shaped hook with squid bait to a wider circle-shaped hook with fish bait. Analyses of observer data showed that, following the introduction of the regulations, significant and large reductions in sea turtle and shark capture rates occurred without compromising target species catches. There was also a highly significant reduction in the proportion of turtles that swallowed hooks and a highly significant increase in the proportion of caught turtles that were released after removal of all terminal tackle. Research suggests that turtles aggregate at foraging grounds and that instituting methods to avoid real-time turtle bycatch hotspots may further reduce turtle interactions.

Summary: To reduce turtle interactions, regulations for the Hawaii-based longline swordfish fishery required vessels to switch from using a J-shaped hook with squid bait to a wider circle-shaped hook with fish bait. Analyses of observer data showed that, following the introduction of the regulations, significant and large reductions in sea turtle and shark capture rates occurred without compromising target species catches. There was also a highly significant reduction in the proportion of turtles that swallowed hooks and a highly significant increase in the proportion of caught turtles that were released after removal of all terminal tackle. Research suggests that turtles aggregate at foraging grounds and that instituting methods to avoid real-time turtle bycatch hotspots may further reduce turtle interactions.

Summary:

In 2003 and 2004 the scallop industry, Coonamessett Farm, and the Virginia Institute of Marine Fisheries, with funding from the NOAA Fisheries Service, successfully tested a series of chains that excluded turtles from entering the dredge bag. In twelve trials, divers videoed the results of placing turtle carcasses in the path of a modified scallop dredge. Turtle carcasses went over the dredge in all but three trials. Damage was assessed as “slight or none” in all valid assessments of damage to a carcass following an encounter.

Summary: Low profile gillnets with a panel height of six feet and no tie downs or additional floats had significantly fewer interactions with sea turtles and caught significantly less bycatch than standard gillnets. Catches of the target species (flounder) were also reduced in the low profile gillnets.

Summary: Low profile gillnets with a panel height of six feet and no tie downs or additional floats had significantly fewer interactions with sea turtles and caught significantly less bycatch than standard gillnets. Catches of the target species (flounder) were also reduced in the low profile gillnets.

Summary:

The catches from five experimental trawls (TED + fisheye BRD, upward facing TED, downward facing TED, bigeye BRD and square-mesh panel BRD) were compared to those of the standard twin Florida Flyer prawn trawl. Nets with a combination of a TED and BRD reduced sea turtle catches by 100%, large sponges by 85.3%, sharks by 36.3% and rays by 17.7% and reduced the proportion of soft and damaged prawns by 41.6% and catches of tiger prawns by 6.5%. Upward and downward facing TEDs reduced sea turtle bycatch by 99% and 100% respectively and large sponges by 81.6% and 95.9% respectively. Catches of tiger prawns (P. semisulcatus and P. esculentus) were reduced by 6.3% with the use of TEDs. The BRDs had little impact on the catch of either target or bycatch species.

Summary: A semi-flexible exclusion grid with a bar spacing of 15.5 cm reduced dolphin bycatch in the Pilbara trawl fishery by close to 50% and reduced the bycatch of sea turtles, large sharks and rays. However, the fate of the dolphins that encountered the grid and escaped is unknown.

Summary:

The addition of a filter grid (inclined at ca. 20 degrees) that leads to an escape tunnel in trawl nets allowed 100% of rays and turtles to escape, 75% of manta rays, 40% of billfish and between 20-75% of sharks to escape.

Summary:

The catches from five experimental trawls (TED + fisheye BRD, upward facing TED, downward facing TED, bigeye BRD and square-mesh panel BRD) were compared to those of the standard twin Florida Flyer prawn trawl. Nets with a combination of a TED and BRD reduced sea turtle catches by 100%, large sponges by 85.3%, sharks by 36.3% and rays by 17.7% and reduced the proportion of soft and damaged prawns by 41.6% and catches of tiger prawns by 6.5%. Upward and downward facing TEDs reduced sea turtle bycatch by 99% and 100% respectively and large sponges by 81.6% and 95.9% respectively. Catches of tiger prawns (P. semisulcatus and P. esculentus) were reduced by 6.3% with the use of TEDs. The BRDs had little impact on the catch of either target or bycatch species.