Summary

Description

Drs. Marla Holt, Brad Hanson, and Candice Emmons of the NWFSC, along with collaborators from Cascadia Research Collective and UC Davis, are currently conducting a study using digital acoustic recording tags (DTAGs) to examine sound exposure, sound use, and behavior of Southern Resident killer whales (SRKWs) in core summer habitat. The DTAG is suction cup attached and consists of a number of different sensors that record sound, pitch, roll, heading, and depth. The tag was developed by Woods Hole Oceanographic Institution specifically to monitor the behavior of marine mammals and their response to sound, continuously throughout the dive cycle. Prey samples and vessel data are also concurrently collected relative to tagged whales in a manner similar to previous work. The project research goals include the following: (1) Measure noise levels in biological relevant frequency ranges that are received by individual SRKWs. (2) Quantify the relationship between vessels and received noise levels. (3) Determine acoustic behavior during different activities and matched with fine scale details on movement, especially those indicative of foraging. (4) Quantify foraging efforts and determine potential effects of vessels and associated noise levels. The results of this study will provide pertinent data to address multiple risk factors of SRKWs including vessel disturbance, noise exposure, effects on foraging, and cumulative effects. The specific work that will be done includes experimental design, data collection, data analysis, and writing for submission to peer-reviewed journals. Southern resident killer whale tag data