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  • Passive acoustic monitoring of harbor porpoises in Puget Sound


Northwest Fisheries Science Center (NWFSC) Conservation Biology CB - Ecosystem Science


PAM of Harbor Porpoise
Passive acoustic monitoring of harbor porpoises in Puget Sound
Drs. Marla Holt, Brad Hanson, and Candice Emmons of the NWFSC, along with efforts from the NWFSC dive team (coordinated by Nick Tolimieri), are currently conducting passive acoustic monitoring of harbor porpoises in Puget Sound. The occurrence of harbor porpoises are being acoustically documented using porpoise detectors (CPODs, made by Chelonia, Ltd), which detect and log harbor porpoise echolocation clicks and store the data on flash memory cards. CPODs are deployed on the sea floor by scientific divers, and must be recovered every three months to replace batteries and memory cards. The project is ongoing, and will document occurrence and habitat use of this protected marine species. The project is a well-defined component of a larger study that addresses harbor porpoise occurrence and habitat use in the Salish Sea.

Research Themes

Habitats to support sustainable fisheries and recovered populations
Healthy oceans, coastal waters, and riverine habitats provide the foundation for aquatic resources used by a diversity of species and society. Protecting marine, estuarine and freshwater ecosystems that support these species relies on science to link habitat condition/processes and the biological effects of restoration actions. The NWFSC provides the habitat science behind many management actions taken by NOAA Fisheries and other natural resource agencies to protect and recover aquatic ecosystems and living marine resources. The NWFSC also maintains a longstanding focus on toxic chemical contaminants, as a foundation for regional and national research on pollution threats to fisheries and protected resources.

Research Foci

Characterize the interaction of human use and habitat distribution, quantity and quality
The ability to define the state of an ecosystem requires insight into the natural processes within habitats, and how anthropogenic interactions with these processes can alter ecosystems and marine organisms. A wide diversity of human activities -- land use and water withdrawals, industrialization and dredging, fishing practices and climate change (e.g., ocean acidification) -- directly and indirectly impact critical freshwater, estuarine, and marine habitats. To best manage west coast marine, estuarine and freshwater habitats in a sustainable fashion, it is necessary to map the spatial and temporal footprint of human impacts and review their potential biological impact on each species of interest. Measurement parameters will be developed to determine the full range of human impacts using spatial data and improved habitat classification.


acoustic porpoise detector (type of recorder used)
harbor porpoise
Phocoena phocoena
passive acoustic monitoring
using passive acoustics for harbor porpoise detection


None associated


Species Phocoena phocoena
bay porpoise, bucker, common porpoise, harbor porpoise, harbour porpoise, herring hog, hogfish


Brad Hanson
Candice Emmons
Internal Collaborator
Marla Holt
Principal Investigator
Nick Tolimieri