Center for Marine Biodiversity and Conservation

The sperm whale (Physeter macrocephalus), the largest toothed whale, is a globally distributed, deep-diving marine mammal known for pronounced sexual dimorphism and complex social structure. In the northeastern Pacific, key aspects of their ecology—including movement patterns, stock structure, the connection between high-latitude males and breeding groups, and regional site fidelity—remain poorly understood. This study aims to improve understanding of the geographic and temporal movements of individual whales and contribute to an ongoing assessment of demographically independent populations (stocks) in the eastern North Pacific.

Using the non-invasive method of photo-identification (photo-ID), we compiled a catalog of 90 individual sperm whales from 19 research cruises conducted between 1991 and 2024. These data, archived in the Southwest Fisheries Science Center (SWFSC) catalog, support efforts to map distribution, identify movement patterns, and behavior and will be made publicly available as a NOAA Fisheries Technical Memorandum.