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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: Leaders in offshore, deep water pound nets in the Virginia portion of Chesapeake Bay incidentally take protected sea turtles. To reduce this take, federal resource managers restricted the use of traditional leaders during periods of peak sea turtle strandings. In response to these restrictions, a modified leader was developed. Testing of the new design in 2004 and 2005 indicated that the modified leader significantly reduced sea turtle interactions. Finfish were also sampled from the nets in the study, with results showing no difference in catch weights of four finfish species and the experimental leader harvesting significantly more of a fifth species than the control.

Summary:

Fishery observer data was used to estimate interactions between hard shelled sea turtles and dredge gear in the US Mid Atlantic before and after the implementation of chain mats.  A total of 288 annual interactions between hard shelled sea turtles and dredge gear were estimated to have occurred between 2001 and 2006, while 20 annual interactions occurred between 2006 and 2008, after chain mats were introduced into the fishery.  If chain mats had not been used during this second time period (2006-2008), it was estimated that 125 interactions would have occurred. Therefore, the introduction of chain mats reduced the rate of interactions between hard shelled sea turtles and dredge gear.

Summary:

Two new types of turtle excluder devices were tested in the Northern Australia prawn fishery, to determine their ability to exclude sea turtles from capture.  The first design, JT 1, had a large escape opening across the width of the top panel ahead of the codend, with the forward edge of the escape weighted down and the aft edge buoyed.  This design did not prevent the capture of sea turtles or other large sharks and rays but caught 6.6% more tiger prawns and 10.5% more endeavour prawns than the standard net.  The second design, JT 2, had two large holes (200 cm long x 30 meshes deep) cut into the side panels of the net ahead of the codend with the aft edge weighted and two standard (40 mesh wide) bigeye escape panels were added between the two side openings.  The second design also did not prevent the capture of sea turtles or other large sharks and rays but did reduce finfish bycatch by 5% and caught 5.2% more tiger prawns and 6.9% more endeavour prawns compared to standard nets.

Summary:

Two new types of turtle excluder devices were tested in the Northern Australia prawn fishery, to determine their ability to exclude sea turtles from capture.  The first design, JT 1, had a large escape opening across the width of the top panel ahead of the codend, with the forward edge of the escape weighted down and the aft edge buoyed.  This design did not prevent the capture of sea turtles or other large sharks and rays but caught 6.6% more tiger prawns and 10.5% more endeavour prawns than the standard net.  The second design, JT 2, had two large holes (200 cm long x 30 meshes deep) cut into the side panels of the net ahead of the codend with the aft edge weighted and two standard (40 mesh wide) bigeye escape panels were added between the two side openings.  The second design also did not prevent the capture of sea turtles or other large sharks and rays but did reduce finfish bycatch by 5% and caught 5.2% more tiger prawns and 6.9% more endeavour prawns compared to standard nets.

Summary:

Pelagic longlines targeting bigeye tuna (Thunnus obesus) and lustrous pomfret (Eumegistus ilustris) in Hawaii were weighted with lead weights, enabling fishing 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 hooks or 41 kg/100 hooks).  Bigeye tuna CPUE for the weighted gear was higher, 0.95 fish/100 hooks (36 kg/100 hooks), compared to traditional gear, 0.56/100 hooks (21 kg/100 hooks).In a second trial in a fishery targeting tuna and billfish, swordfish (Xiphias gladius) CPUE was very similar for weighted (0.3 fish/100 hooks or 17 kg/100 hooks) and traditional (0.25 fish/100 hooks or 14 kg/100 hooks) gear.  This technique could be used to reduce sea turtle and other bycatch species interactions, however this was not tested during this initial trial study.

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:

Tests were conducted on tuna longline fishing vessels in the eastern Pacific Ocean to determine if the use of J (size 4.0 traditional) or circle hooks (sizes 15, 16 and 18) and different bait resulted in differences in the catch rates of target and bycatch species. No significant differences in catch rates of the target species were found between hook types. Significant differences between J and circle hook size 15 and between J and circle hook size 16 were found in the bycatch species group (all species grouped together). The highest catch rates for tunas were found on circle hooks size 15 and for billfishes on J hooks. The largest circle hook (18) had the lowest catch rates. Squid and jack mackerel bait had the highest catch rates for tunas and other fishes, while chub mackerel bait caught the most billfish and sharks.

Summary:

Visual cues are important in sea turtle foraging behavior and likely influence their interaction with fishing gear. This studey examined the potential effectiveness of three visual cues: 1) shark shapes, 2) illumination of nets by LED lights, and 3) nets illuminated with chemical lightsticks - for reducing green sea turtle bycatch in gillnets. The presence of shark shapes significantly reduced mean sea turtle catch rates by 54%, but also reduced target catch by 45%. Nets illuminated with LED lights significantly reduced sea turlte bycatch by 40% and had negligable impact on target catch. Lastly, nets illuminated with chemical lightsticks also reduced sea turtle catch rates by 60% and had no significant impact on target catch. 

Summary:

Visual cues are important in sea turtle foraging behavior and likely influence their interaction with fishing gear. This studey examined the potential effectiveness of three visual cues: 1) shark shapes, 2) illumination of nets by LED lights, and 3) nets illuminated with chemical lightsticks - for reducing green sea turtle bycatch in gillnets. The presence of shark shapes significantly reduced mean sea turtle catch rates by 54%, but also reduced target catch by 45%. Nets illuminated with LED lights significantly reduced sea turlte bycatch by 40% and had negligable impact on target catch. Lastly, nets illuminated with chemical lightsticks also reduced sea turtle catch rates by 60% and had no significant impact on target catch.