Each fall, the waters of Whatcom Creek fill with salmon, swimming upstream from the ocean to spawn. With the flood of salmon comes increasing numbers of seals in search of a feast, threatening the fragile salmon populations.
The complicated relationship between salmon and seals is of interest to the commercial and recreational fishing industries, tribal members and scientists alike. WWU graduate student Kathleen McKeegan and Professor of Biology Alejandro Acevedo-Gutierrez are working to discover the hidden dynamics of this relationship by carefully observing the seals’ hunting behavior from the air.
Harbor seal populations have increased since the implementation of the Marine Mammal Protection Act in 1972, making them an ecological success story; but while seal populations are thriving, salmon species with similar protections are not.
“The protection of one species might actually be impacting the ability for another species to recover,” said McKeegan.
Normally, harbor seals are solitary animals, but during the salmon run each fall, their food source in Whatcom Creek is so plentiful that multiple seals will gather there to hunt. McKeegan and Acevedo-Gutierrez are curious if the seals use cooperative hunting in these situations. Their research is inspired by the previous work of Western undergrads Madison McKay and Delaney Adams, who found a positive correlation between the number of fish caught by seals and the number of seals in the creek at one time.
To monitor seal activity, the marine mammal team will collect observational data about 4 or 5 times per week throughout fall quarter. Most of the data will be collected by undergraduate research assistants who will sit by the creek, take pictures of the seals and record their behavior, paying particular attention to behavior related to hunting and foraging.
In addition to the typical observation techniques of watching the seals from land, McKeegan and Acevedo-Gutierrez are pairing up with Huxley College’s David Wallin and Lummi Indian Business Council GIS Manager Gerald Gabrisch to use unmanned aerial vehicles (also known as “drones” or UAVs) to watch the animals. Wallin has used drones on many projects in the past, including scouting for elk in the Skagit Valley and mapping the eelgrass of Padilla Bay. If all goes well, the drones will allow the researchers to monitor seal activity from above, giving them a clear view down into the water.
“It allows us to get a lot of data because if you can record for 20 minutes what's going on, you can really analyze the behavior that's happening and how close the seals are to each other,” said McKeegan.
McKeegan received her bachelor’s degree in biology from Whitman College in Walla Walla. Although Whitman is landlocked, she maintained a love for the ocean that she developed growing up in her hometown of Oak Park in Southern California. Upon graduation from Whitman, she took on a service term with AmeriCorps in Port Angeles working as an environmental educator and outreach specialist for the Olympic Coast National Marine Sanctuary. For the next couple years, she continued to hop around between jobs that allowed her to stay near the sea and pursue her love for marine biology and conservation.
A deep dive on the internet pointed her towards Acevedo-Gutierrez and his work with harbor seals. Acevedo-Gutierrez has been a faculty member at Western Washington University since 2002, but he’s been in the field of marine mammal research for much longer. Throughout his over 30 years in the field, he studied everything from bottlenose dolphins in Costa Rica to blue whales in Santa Cruz. Most recently, he is researching the seals of Bellingham Bay. Now, with the help of Acevedo-Gutierrez's expertise, McKeegan is taking on this new project, studying seal hunting behavior in hopes of improving conservation efforts.
The team is currently in the process of conducting test runs with drones, but a majority of their work will take place this fall when the salmon run begins.