New Zealand Fur Seals: treasure, resource and vermin
Chris Lalas, Sanford South Island Ltd
Corey J A Bradshaw, Department of Zoology, University of Otago
Human exploitation has been the driving factor in the population and distribution of New Zealand Fur Seals (Arctocephalus forsteri) through the last millenium. The species was eliminated from North Island and most of the South Island by Maori subsistence hunting and later brought to the brink of extinction by commercial sealing on subantarctic islands. The ongoing recolonisation of mainland New Zealand in recent decades has raised issues of debate and conflict on the future of the species. Opinions vary from preservation to extermination. We discuss management options in terms of feasibility, practicality and outcome. The most controversial issue involves the interaction between fur seals and commercial fisheries. One extreme calls for the closure of the West Coast South Island offshore trawl fishery because fur seals are drowned in nets. The other extreme promotes the extermination of fur seals because they are competitors that reduce fish stocks. Rapid increases in the breeding population of fur seals around South Island indicates that present rates of fisheries-related mortality are not a threat to the species. Conversely, extermination is unlikely to result in an increase in fisheries catches because fur seals form only a minor component in the depredation of fish stocks. Issues with fur seals ashore include interactions with people and impacts on foreshore habitats. A return to commercial sealing is unlikely given current public opinion and market resistance. However, fur seals are one of very few native species that could sustain Te Tikanga Maori o Mahinga Kai, the traditional harvest of wildlife by Maori. The most lucrative option is non-consumptive exploitation through tourism that must address conservation issues in order to remain viable. New Zealand Fur Seals offer a rare and exciting opportunity to test theoretical processes of population expansion and recovery that can be tested in a kind of natural experiment. The creation of models to define population dynamics will then be applicable to recovery plans for other species.