2024-2025 LIVING MARINE RESOURCES (LMR) PROGRAM GENERAL ENVIRONMENTAL NEEDS

The goal of this study is to leverage past and ongoing SMRT tag deployments toward a more comprehensive understanding of cetacean responses to CAS and other sound sources. Contractor will use the description of an SQS-53 CAS signal provided by the Navy, and work with the LMRAC and NUWC/M3R to verify if similar waveforms recorded are CAS or other high duty cycle sound sources. Waveforms will be grouped into PAS, CAS, and unknown signal types in analyses unless further classification of unknown signals becomes possible in the future.

While this project may ultimately include some field work to facilitate targeted data collection when needed, the focus will be on analysis, including support for additional data processing, model development, and capacity building. It will also support the dissemination of results through peer-reviewed publications and presentations of findings.

Primary analyses will evaluate the following hypotheses related to CAS:

• Exposure to CAS will result in identifiable changes in diving and vocal behavior of individual tagged whales.


• Responses to CAS will differ from responses to PAS in similar exposure contexts (e.g., maximum received level, cumulative sound exposure level, waveform duration, distance to source).

Secondary analyses may be identified in the course of this work, and this project will contribute to stronger baseline behavioral estimates for study populations and species of interest going forward. The results will be applicable to all Ziphius study populations going forward and provide data to the acoustic thresholds which drive takes.