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Summary: Modified ground gear, known as batwing otter boards, created less disturbance to the seafloor than traditional otter boards in the Australian prawn trawl fishery, decreasing bycatch of benthic squirts and starfish by approximately 85-90%. The target catch of both prawns and scallops decreased by about 10%. Modified ground gear, called soft-brush ground gear, reduced bycatch of starfish by 35% but increased bycatch of nektobenthic species including small crabs and non-target prawns in the Australian prawn trawl fishery. The target catch of prawns decreased 10% while scallop catch increased 10%.

Summary: Modified ground gear, known as batwing otter boards, created less disturbance to the seafloor than traditional otter boards in the Australian prawn trawl fishery, decreasing bycatch of benthic squirts and starfish by approximately 85-90%. The target catch of both prawns and scallops decreased by about 10%. Modified ground gear, called soft-brush ground gear, reduced bycatch of starfish by 35% but increased bycatch of nektobenthic species including small crabs and non-target prawns in the Australian prawn trawl fishery. The target catch of prawns decreased 10% while scallop catch increased 10%.

Summary: Preliminary results indicate square mesh codends on trawl gear, used with turtle excluder devices, decreased bycatch of small fish, small crabs, sea urchins, shellfish, and undersize scallops when compared to standard diamond-mesh net codends. Catch of targeted scallop and prawn were not reduced by the square mesh codends.

Summary: Modified ground gear in the North Sea brown shrimp (Crangon crangon) bottom trawl fishery utilized electromagnetic deterrents and a raised groundrope to obtain catch separation. Preliminary results of the modified gear indicate a selective effect on fish and invertebrate species. Bycatch of various fish and invertebrate species were decreased with a negligible effect on shrimp catch. The results showed great promise, but the authors indicate more testing is necessary.

Summary: Modified ground gear in the North Sea brown shrimp (Crangon crangon) bottom trawl fishery utilized electromagnetic deterrents and a raised groundrope to obtain catch separation. Preliminary results of the modified gear indicate a selective effect on fish and invertebrate species. Bycatch of various fish and invertebrate species were decreased with a negligible effect on shrimp catch. The results showed great promise, but the authors indicate more testing is necessary.

Summary: A hydrodredge was tested using water pressure created from the hydrodynamics of the gear to lift scallops out of the seabed. The hydrodredge when compared to a more traditional dredge increased catch of surface-dwelling scallops but decreased catch of deeper-dwelling scallops. Bycatch of starfish, crabs and urchin were less likely to suffer fatal injuries in the hydrodredge.

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:

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:

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:

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.