Zones of impact around icebreakers affecting beluga whales in the BeaufortSea

A software model estimating zones of impact on marine mammals around man-ma de noise [C. Erbe and D. M. Farmer. J. Acoust. Sec. Am. 108, 1327-1331 (200 0)] is applied to the case of icebreakers affecting beluga whales in the Be aufort Sea. Two types of noise emitted by the Canadian Coast Guard icebreak er Henry Larsen are analyzed: bubbler system noise and propeller cavitation noise. Effects on beluga whales are modeled both in a deep-water environme nt and a near-shore environment. The model estimates that the Henry Larsen is audible to beluga whales over ranges of 35-78 km, depending on location. The zone of behavioral disturbance is only slightly smaller. Masking of be luga communication signals is predicted within 14-71-km range. Temporary he aring damage can occur if a beluga stays within 1-4 km of the Henry Larsen for at least 20 min. Bubbler noise impacts over the short ranges quoted; pr opeller cavitation noise accounts for all the long-range effects. Serious p roblems can arise in heavily industrialized areas where animals are exposed to ongoing noise and where anthropogenic noise from a variety of sources a dds up. (C) 2000 Acoustical Society of America. [S0001-4966(00)04409-X].