HARBOUR PORPOISE RESEARCH

Whaleman is assisting Anna Hall, a graduate student in the University of Vancouver's Marine Mammal Science Department, with the first comprehensive research study of harbour porpoise in the San Juan and Gulf Islands. Harbour porpoise are being seen with increasing rarity in the southern Vancouver Island region and there is insufficient scientific information to accurately assess the status of this population. Anna's goal is to determine population size, seasonal distribution, habitat requirements and diet of harbour porpoise in the inshore waterways of southern British Columbia. She is developing a simulation model to predict population fluctuations based on a variety of parameters. The results of this study will provide the first comprehensive survey of population viability and population size of harbour porpoise in this region and the model should provide insights into the long-term viability of the population.

Harbour porpoise populations around the world are declining due to a variety of human impacts. Anecdotal evidence implies the harbour porpoise population has been declining in some areas of southern British Columbia since the 1940's (Baird and Guenther 1994). Because of their often near-shore distribution, human activities may seriously affect harbour porpoise viability. Some of these pressures include collisions with boats and ships, pollution from marinas and shipyards and freighter anchorage. The harbour porpoise population is also thought to be threatened by increasing pollutant levels, entanglement in fishing nets (especially for juveniles) and possibly reduced prey availability (Raum-Suryan 1995). It is yet undetermined to what extent the increase in human activity has caused or contributed to, the decline of the harbour porpoise population in the south Vancouver Island region. With pressures continuing to mount as the human population increases in the area, we may find the harbour porpoise population is in serious decline. This would then require implementation of a habitat or species recovery program (as demonstrated on the East Coast of Canada).

The development of a model able to predict population fluctuations is invaluable to the development and maintenance of small cetacean conservation plans. Model parameters will be taken from published data collected on Atlantic harbour porpoises, from our line current research data, and from the growing information being gathered from stranded animals collected in southern British Columbia. The goal will be to contrast output from this model with results generated with data from other coastal regions with small cetaceans. Thus, the model has the potential to assist in conservation and resource management of small coastal cetaceans globally.

The results of this study will provide the basis for a long-term monitoring program in southern British Columbia for harbour porpoise. This is of critical importance in the region as the human population of the lower mainland, Gulf Islands, Victoria and the Seattle area is expected to continue to increase. Results will be made available to the Department of Fisheries and Oceans, the University of British Columbia, the commercial wildlife viewing industry and recreational boating associations.