Researchers anticipate occasional shark strandings, say they’re not the ‘worst thing’
Off the Washington coast and occasionally in the Straits of Juan de Fuca and Georgia lurks a “mini-me” of the great white shark.
Though they are less than half the size, salmon sharks don the distinctive countershading of white sharks, and the similarities do not stop there. Salmon sharks, along with whites and makos, belong to the order Lamniformes or mackerel sharks. These sharks have a rare ability called regional endothermy, sort of a cross between warm and cold blood, where they can maintain their body temperature above the water temperature.
“Salmon sharks are very, very strong,” said Washington Fish and Wildlife shark researcher Lisa Hillier. “Their jaws are strong. Their cartilage is a lot more robust than a sixgill or a sevengill shark, because they have to catch bigger, faster prey.”
Strandings
When Hillier comes across salmon sharks, it’s usually in the case of bycatch or strandings, she said. Salmon sharks sometimes get tangled in nets at hake fisheries the department manages.
This summer, a large salmon shark was caught and harvested in Elliot Bay by a tribal member, she said.
“There’s nothing to prevent people from eating them or enjoy them even though they are very high in heavy metals and contaminants,” Hillier said.
Able to tolerate very cold water, salmon sharks pup in California and migrate up to Alaska. Along the way, the young sharks often wash up on Washington beaches.
“Every year we get more mortalities of salmon sharks on our outer coast,” Hillier said. “It’s always on a Friday, because that’s when people are out enjoying the beach. I have not had one this year, but the last one I did have was in August of 2025, so I will be expecting some mortalities of juvenile salmon sharks coming up on our beach.”
Strandings are random and occur across a variety of species, she said. In 2024, she recorded four salmon sharks, two tope sharks, three sleeper sharks and a sixgill that had washed up on Washington beaches.
2025 was a rough year for thresher sharks, she said, when she recorded three strandings. This was likely because of an algal bloom, as there were no signs of being struck by a boat or other damage.
“Their stomachs were very, very green, which is very unusual,” she said. “I collected a stomach sample, but I haven’t had time to analyze that yet. I’m assuming that it has something to do with harmful algal bloom as opposed to a low dissolved oxygen event or starvation. They all looked like they were doing OK before they died.”
Salmon sharks are not protected, though it’s difficult to know quite how abundant they are, Hillier said. They fall under the highly migratory species designation by the Pacific Fisheries Management Council. This means that Washington waters are a crucial element of their lifecycle, but they do not linger very long.
“The animals don’t belong to one state or one country. They just kind of move all over the place,” Hillier said. “It’s really hard to manage sharks in particular that don’t stay, like a rock fish on a pile of rocks. They live vast distances in their life cycle and their lifespan. So, you know, I don’t know how many salmon sharks are out there.”
Young salmon shark strandings can be a good sign, she said. It indicates salmon sharks are reproducing and there are babies in the system.
“Sometimes it’s not necessarily the worst thing to see mortalities of babies on our shores, because that’s just what happens,” she said. “Now, when we stop seeing sharks all together, then that’s the problem.”
Diet
A study published last year in the International Journal on Life in Oceans and Coastal Waters speaks to the difficulty of gathering complete data for such a widely distributed species. Researchers such as Hillier used stomach content and muscle and liver tissue to examine sex-based variation in salmon sharks’ foraging ecology.
The study found that salmon sharks eat ray-finned fish and cephalopods like squid and octopus, but diet varies greatly across sexes and ages. While juvenile females showed the most varied diet, males increasingly took on a niche diet as they become older, indicating nearshore foraging as opposed to the open ocean. While males more often eat “shelf” species, females prefer deep-water squid.
These data help inform management strategies, as different life stages show different levels of vulnerability to environmental changes.
There is little research on salmon sharks in local waters, Hillier said, as they are not a targeted species by fisheries.
When encountering a shark
The most common shark the average person may come across in the Salish Sea is the spiny dogfish, Hillier said.
“There’s a lot of fear in Shark Week, with a person that’s got no arm or got no leg,” she said. “Specifically with spiny dogfish, because people catch them, they think they’re a nuisance and they don’t always treat them very kindly. One of the things we want to really make sure that people know is that they have a very important role in the ecosystem. If you’re damaging them, then you’re damaging the ecosystem. If you do catch a shark, release it gently and let it go back to live its best shark life.”
—By Sam Fletcher