Shark Capture and Diposition in the Hawaii Pelagic Longline Swordfish and Tuna Fisheries

Since regulations designed to reduce interactions with sea turtles in the Hawaii-based pelagic longline swordfish fishery came into effect in May 2004 (the fleet switched from using a 9/0 J hook with squid bait to a wider 18/0 10 degree offset circle hook with fish bait) there has been a significant 36% decrease in shark (combined species) CPUE relative to the period before the sea turtle regulations came into effect. The observed decrease in shark CPUE (from 21.9 to 14.0 sharks per 1000 hooks, pre/post 2004) is likely due to the fleet's change from using squid to mackerel for bait.