Flat, undisturbed water lay in Drayton Harbor. No wind was causing any ripples across the bay or out in Puget Sound, for that matter. Surf and white-winged scoters dove around Blaine Pier, occasionally swallowing a mollusk at the surface. A few harbor seals swam in singles and doubles. Sporadically, one would dive, but mostly they seemed content to float. We’d come to search for a yellow-throated loon that had been spotted over the last few days. Carla and I each peered through our respective spotting scopes, checking each of the numerous loons that hunted fish in these marine waters. So far, they all had grayish bills and the other characteristics that identified them as common loons.
Then, several snorts caught my attention. Harbor seals will occasionally do this when they surface, but it seemed like too much for one. Out, a third of the way across toward Semiahmoo Spit, the water churned in a long line, maybe a hundred yards in length and twenty wide. Binoculars flipped to my eyes, and my mind began to race. Initially, I thought otters, but there were dozens of them. Not the right shape for dolphins, either. Finally, their shapes and sizes became obvious, a line of several hundred harbor seals. A pack of them, all congregated together, swimming as a group. I’d never seen this, nor had Carla.
The Pack
The seals swam together, almost shoulder to shoulder. It reminded me of a flock of dunlins flying across the shoreline, twisting and turning in unison. Dunlins will fly like that to make it harder for a falcon to pick one off. These, though, weren’t synchronized like that. But they still traveled like a herd of impalas running across the African plains. Maybe it was predator related.
Harbor Seal Biology
According to Pacific Mammal Research, harbor seals in the Salish Sea have only recently been observed swimming in big groups like this [1]. This behavior was first observed in 2016. The reasons for this behavior remain controversial. Some scientists think it might aid in fishing. Perhaps, a group of seals can surround and corral schooling fish the way white pelicans do in shallow water. The other thought concerns traveling long distances and having more eyes looking for predators, particularly transient killer whales.
Transients are one of three types of orcas found in this area [2] and those three types don’t interbreed. Transients feed on mammals. Currently, Transients and the resident orcas aren’t recognized as separate species [3] but they have separate dialects and don’t interbreed. That is a different issue, one where these three whale types may know more than our science has come to acknowledge. But, these are harbor seals congregated in front of us.
Harbor seal populations in the Salish Sea have steadily increased since 1970, when they were protected under the Marine Mammal Protection Act [4, 5]. Numbers have gone from a thousand or so to more than 10,000. This growth has “fed” an increase in their major predator, the transient killer whale. Whale numbers have increased steadily since then, too. Monika Shields and Scott Veirs have a graph that suggests a fourfold increase in sightings between 2005 and 2017 in the Salish Sea [6]. I’ve seen transients more often than I’ve seen the resident orcas. Each time I’ve seen either, it has been a thrill.
The seal pack moved to our left, toward Drayton Harbor. A few birds took our attention away for several minutes, and when we looked back, the pack had divided. A group of twenty was moving back toward Puget Sound while the majority lingered right at the mouth of the harbor. It was as if they were looking for a leader to tell them what to do next. I noticed my sympathy for them was strong right then. My fingers gripped my binoculars particularly tightly. I would not want to come face to face with a mammal-eating whale. It reminded me of a recent trip to Africa, where we had Masai warriors escort us from the dining area to our sleeping tents. They then zipped us in, with instructions not to open the zipper until they came for us in the morning.
The seals gradually disappeared as our attention returned to birds. My thoughts, though, kept coming back to them. It reminded me how important friends are in navigating our current political and social situation. A pack helps protect us, too.
After a couple of hours of searching, we moved around Drayton Harbor to look again from the pier near Semiahmoo. The birds were abundant but the pack of seals had moved out of sight. At one point, the yellow-billed loon popped onto the surface not far from us, sat there for a few seconds before diving again. This was a life species for me and my 238th bird species in Washington for 2025. I am grateful for the birds!
References
1. Pacific Mammal Research. Harbor seal grouping behavior. 2025 2 January 2026]; Available from: https://youtu.be/fGhP936KuYY?si=k_3KQX_1qExhzTKA.
2. Orca Conservancy. Three Orca Cultures in the Salish Sea. 2025 3 January 2026]; Available from: https://www.orcaconservancy.org/blog/the-three-orca-cultures-in-the-salish-sea#:~:text=Killer%20whales%20are%20some%20of,separation%20from%20each%20other’s%20groups.
3. NOAA Fisheries. New research reveals full diversity of killer whales as two species come into view on Pacific Coast. 2024 3 January 2026]; Available from: https://www.fisheries.noaa.gov/feature-story/new-research-reveals-full-diversity-killer-whales-two-species-come-view-pacific-coast.
4. Elliser, C. Status and trends for harbor seals in the Salish Sea. 2023 2 January 2026]; Available from: https://www.eopugetsound.org/articles/harbor-seal.
5. Marine Mammal Commission. Marine Mammal Protection Act. 2025 3 January 2026]; Available from: https://www.mmc.gov/about-the-commission/our-mission/marine-mammal-protection-act/.
6. Shields, M.W. and S. Veirs. Status and trends of West Coast transient (Bigg’s) killer whales in the Salish Sea. Encyclopedia of Puget Sound 2019 [cited 3 January 2026; Available from: https://www.eopugetsound.org/articles/biggs-killer-whales#:~:text=Here’s%20some%20information%20about%20the%20population:%20*,total%20of%20over%20500%20individuals%20in%202018.
