In early July, the body of a flawless, 250-pound, six-foot Pacific bluefin tuna washed ashore on Crescent Beach.

It puzzled scientists, caught the attention of news outlets and sparked a lively debate about how an animal never before seen in the Salish Sea appeared on Orcas Island.

The cause of death has officially been determined: after venturing into inland waters, the tuna inadvertently beached itself., the tuna inadvertently beached itself.

SeaDoc Society Chief Scientist Dr. Joe Gaydos and Communications Manager Justin Cox (along with his 10-year-old son Noah) were some of the first locals on the scene on July 11. In the months that followed, Cox created a “deep-dive investigation” into the incident on the SeaDoc Society’s “Pod of Orcas” podcast, interviewing the scientist who performed the necropsy, kayakers who likely witnessed the tuna in East Sound in the days before its death and the Orcas man who harvested 45 pounds of sushi before the body was hauled away. The podcast is available at https://podcasts.apple.com/us/podcast/pod-of-orcas-saving-southern-resident-killer-whales/id1557240502?i=1000630340341.

“It was a blast, and I’m proud of it,” Cox said.

According to NOAA, most of the U.S. catch of Pacific bluefin tuna is within about 100 nautical miles of the California coast. They are highly migratory — traveling long distances throughout the Pacific Ocean — and found primarily in temperate ocean waters but also in the tropics and cooler coastal regions. Bluefin tuna are a delicacy that can sell for millions of dollars. Fishermen have reported seeing them far off-shore in Washington state but never has one been documented in the Salish Sea.

When Gaydos first saw the fish on Crescent Beach, his reaction was: “That is a big ass tuna,” although he wasn’t precisely sure what type it was. Notably, it showed up the same day that the “Field Guide to Fishes of the Salish Sea” was released. After flipping through the pages and not seeing it in the guide, Gaydos became excited.

“When it wasn’t in the book, I knew this was something big,” he said.

Gaydos sent a photo to Dr. Adam Summers of the University of Washington Friday Harbor Labs, who quickly responded: “That is a bluefin tuna!”

By the time Gaydos and Cox had arrived that morning, Orcas resident Josh Brown had harvested a 45-pound filet. Gaydos warned him against consuming the meat before a cause of death had been determined, but Brown was undeterred. He even lent his vintage army stretcher and helped SeaDoc staff transport the fish to the public dock in West Sound where collaborators at the University of Washington Friday Harbor Labs picked it up to perform a necropsy. Justin’s son Noah made a sign that read “Fish for scientists” that was placed on the outside of the orange cadaver bag.“It will stick with him forever,” laughed Justin. “Here’s a WWII gurney with a six-foot tuna trailing blood.”

Upon receiving the body, Summers was amazed at the state of the fish, which he estimated to be eight years old.

“It was an incredibly fresh animal; there was arterial red blood, no coagulating,” he said. “It was such a lucky event. We had my whole lab and a group of high school students also stopped by. The tuna was in beautiful shape. Joe told me a local had grabbed a knife and cut off a quarter of the tuna’s flesh and I said, ‘Holy mackerel, we don’t even know what killed it! It was a very good butchering job.”

Brown says he got a call early in the morning on July 11 from a friend who saw the fish. Upon seeing a photo, he immediately got in the car with the biggest filet knife he owned, his stretcher and a tarp. He arrived at Crescent Beach and identified the specimen as a bluefin.

“It looked entirely fresh,” he said. “I knew it hadn’t been there long. When I cut it into it, it was warm and it still bled.”

Brown vacuumed-packed the filets, and for the rest of the summer he fed it to friends and family, who dubbed his house the “Sushi Lounge.”

“He is a master chef and the sushi was delectable,” said daughter-in-law Laura Kussman.

Once news of the tuna had spread, two Orcas kayakers realized they may have seen it around July 4. Jean Agapoff and Hugh Everett, who often kayak off of Crescent Beach in the evenings, recalled seeing an animal swimming back and forth very quickly, leaving a 10-foot wake, over the course of two days. They thought it may have been a minke whale due to its dorsal fin.

“It was an extremely bizarre swimming pattern under the bluff,” Agapoff said. “The following night, we saw it again, swimming along the beach. It was following the beach line very closely both nights. It made me feel like it was an animal pacing in a pen. It was like it was trapped. It was so agitated.”

Summers explained that bluefin tuna are not wired to understand tides or shorelines. He guesses that the tuna was traveling with a large class from California, heading to Japan, when he accidentally separated from the group.

“It was no great surprise that the kayakers saw a big panicked fish zipping back and forth,” Summers said. “Getting stuck is a death sentence. It’s a very fast fish.”

He and his team determined from the gravel and sand in the tuna’s gills and mouth that it “made a bad choice about where to be when the tide dropped.”

“He beached himself and he died. He was in perfect condition. No bruising, no harm,” Summers said.

Once the exam was complete and it was confirmed that the fish was healthy, more filets were harvested and shared among the scientists.

“It was fabulous meat. It did not go to waste,” Summers said.

The skeleton of the animal will be on display at the Burke Museum of Natural History and Culture in Seattle, where it will be the first bluefin tuna specimen in the museum that came from the state of Washington. For now, scientists agree that the appearance of this tuna was a fluke and that it is unlikely more will appear.

“We know we are at the precipice of change due to climate change and the ocean warming, but we can’t say that (this is a trend) with one fish,” Gaydos said.

The full episode can be heard on SeaDoc Society’s Pod of Orcas podcast.

Contributed photo Resident scientist Dr. Karly Cohen stares into the mouth of the tuna, looking at its hundreds of small teeth.

Contributed photo Olivia Hawkins next to the tuna’s first dorsal fin. When the fin is raised it acts as a sail, allowing the fish to make sharp turns while pursuing prey. Dissection revealed the muscle and tendons that help retract the fin for streamlined swimming.