Southeast Alaska Sperm Whale Avoidance Project: Collaboration among fishermen, acousticians, biologists and managers to reduce longline depredation in the Gulf of Alaska.

Abstract

In the eastern Gulf of Alaska, depredation of demersal longline fishing gear set for sablefish (Anoplopoma fimbria) by sperm whales (Physeter macrocephalus) has occurred since at least the mid‐1970s. In 1995, with the implementation of Individual Fishing Quotas, the season expanded from a 2 week derby style fishery to 8 months. This change allowed more opportunity for whales to depredate longline gear and reports of depredation increased resulting in economic loss to the fleet. Beginning in 2003, the North Pacific Research Board funded a collaborative study among fishermen, scientists, and managers to collect quantitative data on longline depredation. The goal of the Southeast Sperm Whale Avoidance Project (SEASWAP) is to determine the mechanics of the depredation, characterize the whales involved, and to recommend changes in fishing behavior to reduce depredation. The longline fleet provided fishing data and allowed researchers to collect behavioral, genetic, and acoustic data in conjunction with their fishing operations. Through this effort, SEASWAP has estimated numbers and sexes of depredating whales, identified long‐range acoustic cues that attract animals to the gear, and systematically tested various depredation reduction strategies, including decoy deployments, active playbacks, and modifications to fishing gear.