Unanswered Forum Topics

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.

The effect of circle hooks and J-style hooks on the catch composition, catch rates, hooking location and status of release of target and bycatch species were compared on pelagic longline vessels.  There were significant differences in catch rates between the two hook types for bigeye tuna, which had higher catch rates on circle hooks and sailfish, pelagic stingrays, and leatherback sea turtles, which had higher catch rates on J-style hooks.  Survival of bigeye and yellowfin tunas was significantly higher when circle hooks were used and bigeye and yellowfin tunas, swordfish and sai

A double codend was compared to the standard codend in the Clarence River penaeid trawl fishery in southeastern Australia, to determine its effects on total catch, retained and discarded school prawns, sizes of discarded prawns, discarded fish and immediate and short-term mortalities of discarded juvenile school prawns.  The only significant difference between gear types was the immediate and short-term discard mortalities, which were reduced by 13.8% and 17.1% respectively when the double codend was used.  Additional analysis also showed that mortalities of school prawns increase

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 me