Responses of wintering humpback whales to vessel traffic

Responses of humpback whales to vessel traffic were monitored over two winter seasons during 1983–1984 in Maui, Hawaii. A variety of vessel characteristics including vessel numbers, speed, and proximity were associated with changes in whale behaviors, including swimming speed, respiration, and social behaviors. Smaller pods and pods with a calf were more affected than larger pods. A case study indicated that a calf could be sensitized by the passby of a large vessel, so that it subsequently breached in response to noise from a smaller boat engine which had not previously elicited any behavior change. These findings in conjunction with similar results from summering humpbacks in Alaska indicated disturbance of humpback whales at both ends of their range. Although substantial short‐term effects were noted, long‐term negative consequences are not apparent. Recent aerial surveys of the Hawaiian Islands indicate substantial increases in the number of humpback whales.