Dear All,
On behalf of Dr. Patrick Miller and the rest of the co-authors I am pleased to draw your attention to a recent paper in Deep -Sea Research on controlled exposure experiments with airguns and Dtagged sperm whales.


Using at-sea experiments to study the effects of airguns on the foraging behavior of sperm whales in the Gulf of Mexico

P.J.O.Miller, M.P.Johnson, P.T.Madsen, N.Biassoni, M.Quero, P.L.Tyack

Acoustic exposure and behavior of 8 sperm whales were recorded with acoustic and movement-recording tags before, during and after 5 separate 1–2h controlled sound exposures of industry-provided airgun arrays. None of the 8 whales changed behavioral state (7 foraging, 1 resting) following the start of ramp-up at distances of 7–13km, or full array exposure sat 1–13km.The most closely approached whale rested throughout exposure but started a foraging dive shortly after the airguns ceased, possibly indicating a delay in foraging during exposure. Using visual tracking and dead-reckoning of tagged animals, we found that their direction-of-movement was random with respect to the airguns, but correlated with the direction-of-movement just prior to the start of exposure, indicating that the tested whales did not show horizontal avoidance of the airguns. Oscillations in pitch generated by swimming movements during foraging dives were on average 6% lower during exposure than during the immediately following post- exposure period, with all 7 foraging whales exhibiting less pitching (p ¼ 0.014). Buzz rates, a proxy for attempts to capture prey, were 19% lower during exposure but given natural variation in buzz rates and the small numbers of whales, this effect was not statistically significant (P ¼ 0.141). Though additional studies are strongly recommended, these initial results indicate that sperm whales in the highly exposed Gulf of Mexico habitat do not exhibit avoidance reactions to airguns, but suggest they are affected at ranges well beyond those currently regulated due to more subtle effects on their foraging behavior.



http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VGB-4VVR1T5-1&_user=642076&_coverDate=03%2F17%2F2009&_alid=929481455&_rdoc=1&_fmt=high&_orig=search&_cdi=6034&_sort=d&_docanchor=&view=c&_ct=1&_acct=C000034578&_version=1&_urlVersion=0&_userid=642076&md5=5c6d46d7a0af28d4d0d79b9e6028f67b