Monitoring Harbor Porpoises

Check out our video presentation about our harbor porpoise research in the Salish Sea!

The harbor porpoise is a top predator feeding on small forage fish, a year-round resident of the Salish Sea, reproduces quickly (in comparison with other cetaceans) at one calf per year, and is sensitive to environmental and anthropogenic changes, making it an ideal indicator species.  However, there is surprisingly little information on a cetacean that is now relatively high in abundance in local inland waters.

We have successfully adapted traditional photo-ID techniques to a new species, the harbor porpoise, which has not been the subject of many ID studies previously due to their lack of obvious natural markings.  Features such as pigmentation, coloration, scars, and dorsal fin markings are used to positively identify harbor porpoise individuals and track them over time.  A matrix was constructed that includes 10 categories of markings, with 3-6 variables for each, allowing a standardized way to describe different identification marks.  We have identified and re-sighted individuals over days, weeks, months and years and currently have over 80 identified individuals in our ID catalog.

In the complex societies of marine mammals, knowing individuals allows researchers to better understand many aspects of their society such as site fidelity, behavior, grouping, habitat use, and association and movement patterns. This is particularly important for the harbor porpoise, which is a very poorly understood species.

Monitoring Harbor Seals

Harbor seals are abundant, year-round residents of the Salish Sea, top predators, reproduce on a yearly basis, and studies on abundance, distribution, food habits, contaminant levels, disease, and life history have all shown measurable changes over time (thus indicating susceptibility to environmental and anthropogenic changes). These attributes make them a valuable indicator species as well. However much of this information has been collected on a larger scale, with less focus on the long-term monitoring of individual animals and local populations.

Although photo-ID of harbor seals was determined possible in the 1990s, little work on individual identification has been conducted in the Salish Sea; PacMam has already identified and re-sighted individuals. Harbor seals are identified by distinct pelage patterns on their neck and sides. We have just begun identifying seals and a matrix is currently being constructed which will be standardized for each body part, similar to the porpoise ID matrix. Given the documented usefulness of photo-ID studies in many species, such research could offer unique insights into harbor seal population parameters, site fidelity and behavior.

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Passive Acoustic Monitoring (PAM)

To record environmental data about specific areas of high habitat usage, PacMam plans to deploy a fixed passive acoustic monitoring (PAM) system designed for long-term monitoring of natural and anthropogenic sounds.  This will enable us to learn more about the habitat these animals are choosing to use on a regular basis, as well as learn about possible anthropogenic impacts and even the vocalizations of the animals themselves.  We also plan to create an online portal where you can listen to some of the sounds recorded, and learn more about the underwater soundscape of Burrows Pass!

If you are interested in learning more about this program or donating to help fund the purchase and deployment of the PAM device, please contact us via email ( or phone (360) 202-2860.