Mitigation of incidental mortality of Australian sea lions in the west coast rock lobster fishery

Abstract

The Australian sea lion is a listed threatened species under Australian Commonwealth legislation, based on limited population size and the likelihood of further declines in population abundance. Incidental mortality of this species in the west coast rock lobster fishery was identified as a key threat to the distinct sub-population of about 700 ind. on the west coast of Australia. Reports of incidental mortalities in this fishery from a variety of fishery-dependent sources suggested that a minimum of 4 to 5 mortalities occur every fishing season. All reported captures were in shallow waters (<20 m) and within 30 km of a breeding colony. Foraging ranges of vulnerable-sized animals were confirmed by use of satellite-linked transmitters and time-depth recorders. Mitigation of this incidental mortality was effected by means of modifying the lobster pots with a sea lion exclusion device within the area of known interaction. The mandatory implementation of this programme resulted in a very high compliance rate (95%) in the first season and was achieved through active consultation and involvement of the industry, and of fishery and wildlife managers. © Inter-Research 2008.