The behavioral response of humpback whales to seismic air gun noise

Abstract

Four major experiments have been conducted off Australia to quantify the behavioral response of migrating humpback whales to various seismic air gun arrays. The first, using a 20 in3 air gun, was used to develop the analysis framework, which was then applied to later experiments. The following two experiments tested a 4-step “ramp-up” procedure (20, 60, 140, and 440 in3 array sequence) and a 140 in3 array. Both studies found a change in movement behavior in response to the air guns, where groups deviated more from their course and made less progress towards the source. There was no evidence of any change in surface behaviors, including respiration rates. The final experiment involved ramp-up to a 3130 in full commercial array. In response, whales decreased their dive time and displayed an elevated respiration rate, more so to the full array phase. In this phase, they also changed their surface behavior, in that breaching rates were elevated but tail and pectoral slapping behaviors were reduced. Consistent...