Direct Observation from a Submersible Vessel of Commercial Longlines for Tilefish

Abstract

In August 1979 the submersible Nekton Gamma was used in coordination with the commercial fishing vessel Lori-L near Hudson Submarine Canyon to evaluate the performance of longline fishing gear. Tilefish Lopholatilus chamaeleonticeps were observed in or entering burrows or hooked on longlines both near burrows and distant from them. Most hooked fish were in good condition; however, some fish were dead from gut hooking and dusky sharks Carcharinus obscurus occasionally took hooked fish on the bottom. Seventeen percent of the catch was lost, apparently when longlines were retrieved and hooks pulled free of fish in burrows. Although the longline moved very little on the bottom, tilefish were attracted from a wider area than that transected by the longline. Bait predation by starfish Astropectin sp. and crabs Cancer sp. and Acanthocarpus alexanderi resulted in 50% bait loss in 4 hours. Bait predation proceeded rapidly; all exposed baited hooks were preyed upon after 3 hours. Minimum soak time may be around 2 hours, and due to 100% bait loss from predation maximum useful soak time is 8 hours.