Introduction & Objectives

The proposed project will support the Navy’s efforts to:
1. Determine which marine mammals (including ESA-listed species) are present within the Navy’s GOA WMA and TMAA.
2. Assess the occurrence and estimate killer whale ecotype-specific density within and near the TMAA and WMA.
3. Determine the seasonality and possible movement patterns of marine mammals within these Navy training activities areas.
4. Apply passive acoustic tools and techniques for detection and classification of marine mammals.
5. Assess occurrence and density of cetacean species within and near the TMAA and WMA.

The specific objectives are:
1. Review existing visual and acoustic information on the occurrence of killer whales in the GOA to design a vessel survey that maximizes the encounter rate of this species in the summer of 2026.
2. Conduct a vessel survey in the GOA to collect visual, acoustic, and molecular data required to determine ecotype identity of killer whale sightings and, if feasible, to deploy satellite transmitting tags to evaluate killer whale ecotype-specific habitat use.
3. Design and conduct a systematic line transect survey to occur in 2026, suitable to support cetacean species density estimates for the GOA TMAA and WMA areas. This survey is expected to overlap or be conducted in conjunction with the killer whale-specific effort above. Data collected from this effort shall be similar and comparable to past Navy and NMFS vessel-based surveys to estimate density and abundance of marine mammals (e.g. GOALS and PACMAPPS) and may include both visual and acoustic survey data.
4. Integrate existing data (e.g., visual surveys conducted by NOAA/NMFS/AFSC in 2009, 2013, 2015, and 2021, and the acoustic moorings) to estimate ecotype-specific seasonal occurrence, density, and abundance of killer whales near and within the TMAA.
5. Analyze and add to the year-round seasonal occurrence information of cetaceans recorded at the three acoustic recorder moorings sites deployed by AFSC since 2023, by providing results from recorders deployed between 2024 and 2026.
6. Combine these new mooring results with other recordings collected concurrently (by AFSC) along the WGOA shelf to investigate whether any movement patterns for any species can be identified.
7. Continue to develop methods for identifying killer whale signals to ecotype within these Navy training activities areas, and provide recommendations for future research.
8. Assess data to determine if acoustic abundance or density information can be derived, and/or identify biological or data limitations (unknown call rates; unknown call localization, need for additional behavioral information, etc.), and provide recommendations for future research.
9. Provide year-round occurrence information for anthropogenic sources at those mooring sites.
10. Provide seasonal measurements of median noise spectral percentiles at those mooring sites
11. Analyze visual sighting data to create density layers for all possible cetacean species.
12. Process 2009, 2013, 2015, 2021, and 2026 Survey data from GOA in a way that Navy can use for NAEMO modeling.
13. Review and provide input to model results that ManTech creates for the Developing Habitat- Based Density Models for Cetaceans in the North Pacific Ocean project.
14. Produce technical and interim reports, and draft manuscripts.

Technical Approach

Progress & Results