Behavioral and Physiological Response of Baleen Whales to Ships and Ship Noise

Abstract

Abstract : We began this study in 2013 with goal of examining the behavioral and physiological response of blue whales to ships and ship noise off California using a combination of opportunistic and controlled research. Ship noise has been identified as the major source of anthropogenic noise in the oceans especially in areas of high vessel traffic. Ship strikes are also a growing concern especially for several species including blue and right whales that appear to be particularly susceptible. In initial research, we demonstrated the feasibility of documenting whale response to opportunistic close approaches of ships made possible by the presence of high levels of ship traffic particularly to the ports of LA/Long Beach passing through areas of known high concentrations of blue whales. This juxtaposition has resulted in high levels of ship strikes (Berman-Kowalewski et al. 2010) as well as potential impacts on vocal detections of blue whales (Melcon et al. 2012). In this study we continue research on behavioral response of blue whales to ship close approaches and specifically examine how this varies with ship speed; this is one strategy proposed to mitigate ship strikes. We will also test the response of blue whales to controlled playback of ship noise to examine the specific cues blue whales respond to and also to allow comparison between how blue whales respond to ship noise and other anthropogenic sounds like mid-frequency sonar. To gain insight into whether ship noise and frequent passages of ships might be causing a stress response, we will compare stress hormone levels in blue whales feeding for extended periods in areas of high ship traffic with those feeding away from shipping lanes.