Harbor Seal and Vessel Interactions in Aialik Bay and Northwestern Fjord, 1996

Tetreau, Michael

National Park Service biological technicians conducted surveys of harbor seal populations in Aialik Bay and Northwestern Fjord during June and August 1996. In addition to counting the number of seals present, observers also recorded information regarding the interactions between harbor seals and vessels, and occasionally between seals and aircraft. Harbor seal numbers in Aialik Bay have declined dramatically since the early 1980 s and there is concern that disturbance by vessels may be further stressing the population. Northwestern Fjord is of particular interest as it has received regular tour boat traffic only since 1995. The goal of the disturbance observations in 1996 was to gather general information that would answer the question "is there a problem here that needs to be addressed further". The observations are primarily subjective, although the census data do reflect the disturbance presumably caused by vessels in many cases. Estimations of the distance between vessels and seals are very rough (based solely on the judgment of the observer) and distances were not recorded for every observation.