The Conservation & Science team at the Monterey Bay Aquarium has worked for more than two decades to understand and recover bluefin tuna—particularly Pacific bluefin, whose population has declined historically due to overfishing. A key piece of our efforts is tagging bluefin in the wild so we can document their migrations across ocean basins. Much of our work takes place in the Eastern Pacific, but this summer we’re partnering with Japanese colleagues to tag bluefin tuna in the Sea of Japan. Tuna Research and Conservation Center Research Technician Ethan Estess, working with Program Manager Chuck Farwell, is chronicling his experience in the field. This is the fourth and final dispatch in his series.
Last night got a little wild. We haven’t seen a bluefin tuna in nine days, and we’re all starting to go a little stir-crazy. That night over dinner, we have beverages. Fine Japanese beverages. And after dinner? More beverages. Lo and behold, the restaurant owner pulled out the karaoke machine.
I was first to the microphone with a reliable jam, “Under Pressure” by the late David Bowie and Queen. I didn’t realize the karaoke machines here have a complex vocal analysis system that scores your performance. Let’s just say I didn’t go platinum. (Definitely a problem with that karaoke software.)
It was Dr. Ko Fujioka who put on the winning performance of the night: a classic Japanese pop song from the ’80s. Fujioka-san rocked it, getting a high score of 91.7 points, the third-highest in the restaurant’s history. People were dancing and cheering—karaoke is a big deal here.
Then researcher Mitsuake Sato got up and sang a powerful love ballad, replacing the female subject’s name with maguro (Japanese for “bluefin”). In tears from laughing, we went to bed, glad to have vented our Bluefin Blues in some way.
Getting up at 4 a.m. the next day was more difficult than usual for some reason. I awoke to the sound of rain battering my windowpane. Getting to the dock, we could see the spray flying over the seawall. The ocean’s surface had been dead-flat the past 10 days, but as we rounded the jetty to leave the harbor, we were greeted by a solid six-foot groundswell and fresh breeze from the general direction of Siberia. Our captain barked over the loudspeaker, warning us not to stand on the front deck. Sure enough, a minute later we were taking some solid water over the bow.
We finally reached the tuna trap. The other barge, carrying the fishing crew, showed up and began to haul in the net. Slowly, the boats crept together as the net tightened between them, the fishermen straining as they tugged on each handful. Before long, we were lurching as close as six feet from the other vessel, rail-to-rail in high seas.
The sea surface was so agitated with wind and rain, it was hard to see into the trap. All I could make out was a big layer of jellyfish at the surface.
One of the fishermen spotted them first. “Maguroooooo!” rang out between the boats. Large bluefin began breaking the surface, the net around them cinching tighter.
Then everything happened fast. The hydraulic crane sang to life, and the giant dip net reached into the tuna trap. I ducked as an enormous bluefin swung over my head in the net, a yellowtail hamachi bouncing off my hard hat.
Chuck and PhD student Hiro Yamane reached into the net and slid the tuna onto the tagging mat. The team put a seawater hose in its mouth and a cover over its eye. Dr. Fujioka stepped in and placed the satellite tag on the tuna’s back. After taking a DNA clip from its fin and a small biopsy sample, we hoisted the fish over the side. It weighed in at 170 pounds and more than 5 feet long. “That one is heading to the spawning grounds!” I yelled to Fujioka-san.
But there was no time for small talk. The fisherman had already netted the next tuna and it, too, was flying at my head toward the surgery station. Dr. Fujioka, Chuck, and the team worked together like a pit crew, efficiently collecting samples, attaching tags and releasing each bluefin as the fishermen netted the next one. Twelve minutes and eight large bluefin later, we had run out of tags.
The next day was a big catch too, but this time the weather was sunny and calm. We tagged and released 10 more bluefin ranging from 60 to 130 pounds. Eight months from now, the tag data should be bouncing off a satellite to our laptops.
“Well,” I said to Dr. Fujioka, “I guess bluefin like karaoke.”
It’s been a productive trip. Chuck and I, representing Monterey Bay Aquarium, are honored to have been welcomed here in Japan by Dr. Fujioka and Far Seas Fisheries. It is only through collaborative efforts, information sharing, and science-based dialogue that our nations will be able to collaborate and promote sustainable bluefin fisheries across the Pacific.
I’ve eaten more fresh, local seafood than I ever thought possible. And from the Sado Island locals to the commercial tuna fishermen, I have been overwhelmed by the kindness and hospitality of the Japanese people.
Domo arigatou gozaimasu!
Photos by Monterey Bay Aquarium/Ethan Estess.
Featured image: A large bluefin is netted and lifted with a hydraulic crane to the tagging station.
Conservation & Science 
Great post and great work, Ethan and Chuck! I look forward to interpreting your work to the public some day.
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