POPULATION ANALYSIS OF NORTHERN BOTTLE-NOSED WHALES IN THE GULLY, NOVA-SCOTIA

Northern bottlenose whales (Hyperoodon ampullatus) are consistently fo und through the year in the Gully a prominent submarine canyon on the edge of the Scotian Shelf. Individuals were photographically identifie d during field studies between 1988 and 1995. About 70% of the populat ion is identifiable, and 29% have markings which persist reliably over periods of years. A mark-recapture analysis of photographic individua l identifications collected between 1988 and 1995 indicates that the p opulation using the Gully numbers about 230 animals (approximate 95% c onfidence interval 160-360). The rate of mortality plus emigration plu s mark change (in animals with reliable long-term marks) is about 12% per year, although this estimate has wide and uncertain confidence lim its. Members of the Gully population, which includes calves and mature males, are shorter than animals caught: off Labrador. The small size of the Gully population and its persist ent use of a very small, bathy metrically unique ocean area make it vulnerable to human disturbance.