San Diego, CA
Snorkelers found a rare deep-sea fish off La Jolla. It took ‘a community effort’ to haul it to shore to study.
Emily Miller and her friends had planned for a relaxing day of kayaking in La Jolla last weekend — a reunion of sorts for the former roommates.
But when they reached La Jolla Cove, the kayakers — most of whom are also marine researchers — found themselves with a bit of a “fish emergency” on their hands, Miller said.
Nearby snorkelers had found a roughly 12-foot dead oarfish, a rare species of deep-sea fish, lying in the seagrass at the cove. This discovery last Saturday was significant; fewer than two dozen oarfish have washed up in California since 1901, according to the Scripps Institution of Oceanography.
The oarfish, which can grow to be around 30 feet long, is often described as a sea serpent and has a reputation as a predictor of natural disasters such as earthquakes and tsunamis, though this myth was debunked years ago.
While the snorkelers examined the unique fish, Miller — a research associate at California Sea Grant and a former commercial fisheries observer — knew that such a rare species washing up in San Diego likely warranted closer scientific analysis. In a lab, scientists can analyze the fish’s gills and body composition to better understand its lifestyle as well as its relationship with the rest of the ocean.
“I jumped in the water and … pushed it up to the surface to get a better look,” she said.
With her friends supporting the fish, Miller threw herself over her kayak, half in the water, and began making some calls — including one to Ben Frable, the collection manager of fishes at Scripps Institution of Oceanography, who helped her notify the NOAA Southwest Fisheries Science Center and local lifeguards.
After determining that the fish could be removed from the marine protected area, it was decided that the kayakers would bring the fish back to shore with them — an effort more easily said than done.
“Our small group had the mission of getting this unwieldy animal to the kayak launch,” Miller said. They struggled to orient the fish onto the kayaks, not wanting to damage the specimen, still mostly intact.
They had all but resigned themselves to swimming back to shore with their heavy haul when two passing paddleboarders offered to help. Their board was an ideal flat surface for carrying the ribbon-like oarfish.
“It was a community effort to get a rare specimen to scientists — and taking all the steps to make sure all the appropriate authorities were contacted,” Miller said. “It was a beautiful example of teamwork.”
The adult male oarfish has spent the last week at the NOAA Southwest Fisheries Science Center. On Friday, scientists conducted a necropsy to determine a cause of death.
It still wasn’t clear why the fish died. There was no evidence of trauma. But the researchers also took gill and genetic samples, along with muscle samples, which can show what kinds of isotopes are stored in the body.
“They’re not like an apex predator … like a tuna or a shark or a dolphin,” Frable explained. “But knowing where they are in this food web, especially here in California, can help us really fill out our understanding of how these kinds of things, like carbon and nitrogen, cycle in the open ocean off the coast.”
After the necropsy, Frable will preserve the fish at the Scripps Marine Vertebrate Collection, where there are six other oarfish, along with the body parts of a few others.
Oarfish live in the deep sea and can be found at depths of as great as 3,000 feet, though it’s more common for them to live around 600 feet below the surface.
It’s rare for them to wash up in California. But Southern California can be a “lucky spot” to see deep-sea fish in general, Frable said, given its proximity to many underwater canyons that make for deep-sea conditions much closer to the shore.
This fish didn’t appear to have been scavenged by other marine animals, such as sea lions or sharks, he points out — a finding that aligns with some other oarfish that have washed up. “It may just be that their skin’s a little too tough and not worth it, or maybe they just don’t taste good,” he speculates, though more research is needed on the subject.
“It’s one of these great examples of all these different things that we still don’t really know about these organisms,” Frable said. “And one of the reasons why, when we get to encounter them like this, there’s so much we can learn.”
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