Long-Term Monitoring of Harbor Porpoises
The harbor porpoise (Phocoena phocoena) 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.
PacMam has successfully adapted traditional photo-ID techniques for the harbor porpoise, which has not been the subject of many ID studies previously due to their lack of obvious natural markings. We use features such as pigmentation, coloration, scars, and dorsal fin markings identify harbor porpoise individuals and track them over time. We created a unique identification matrix that includes 8 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 90 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.
Long-Term Photo-ID Monitoring of 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.
Passive Acoustic Monitoring
To learn more about the soundscape these animals live in, PacMam plans to deploy a fixed passive acoustic monitoring (PAM) system designed for long-term monitoring of natural and anthropogenic sounds. This underwater “microphone” will allow us to learn more about the habitat these animals choose to use on a regular basis, and may even let us record their vocalizations!
We plan to create an online portal where you can listen to some of the sounds we record, and learn more about the underwater soundscape of Burrows Pass! Stay tuned for more on this exciting new project.
Environmental DNA (eDNA)
PacMam’s newest project focuses on the revolutionary technique of collecting DNA material from an animal’s environment. To collect this so-called environmental, or eDNA, we will scoop a sample of seawater where a harbor porpoise just dove, which will contain sloughed off skin cells and other genetic material from the porpoise.
This unique methodology means we can collect genetic material to learn more about the population structure of our Salish Sea harbor porpoises, without even touching the animals!
If you would like to support this latest venture, head to our Donate page now to make a tax-deductible donation!