March 11 marks the fifth anniversary of the devastating earthquake and tsunami in Japan. Visitors to the Oregon Coast Aquarium in Newport, Oregon, can now feast their eyes on a living legacy of that quake and tsunami.
Aquarium staff rescued more than a dozen jacks and one beakfish from the hull of a derelict boat last April. The half-sunk, fiberglass wreck coated in seaweed was the front half of a roughly 50-foot long commercial fishing tender. It appeared to have drifted across the Pacific after 2011's big earthquake and tsunami in Japan--and carried the live fish with it.
"We don't know how old they are,” Oregon Coast Aquarium Assistant Curator Evonne Mochon Collura said. “We don't know how long they were in the hull. It's possible they got washed into the boat hull when they were small."
A second beakfish on display was pulled up in a crab pot near Port Orford two months before the drifting boat hull showed up off of Newport. That surprise, fishy discovery was initially held at Oregon State University's Hatfield Marine Science Center before transfer to the nearby aquarium.
Transitioning to a new home
"They're swimming comfortably among the kelp right now,” Mochon Collura said.
The uninvited fish look right at home. They do stand out from the native fish with which they share their tanks - not quite tropical, but pretty-looking fish and healthy looking.
“They each have a beautiful barred pattern on their bodies, tall vertical stripes that alternate silver and black,” Mochon Collura said of the striped beakfish, also known as barred knifejaws. Then we move to the much larger "Open Sea" tank to look for some bigger arrivals - silver torpedoes with deeply forked yellow tails. These are a school of yellowtail jacks.
Mochon Collura said DNA testing positively identified the now-grown fish as native to East Asian waters. They probably survived by nibbling on sea life that grew inside the hulk and whatever else washed in.
The long-distance hitchhikers were kept in quarantine for six months before being judged safe and suitable to display. Aquarium visitor Nicole Chason of Portland was suitably amazed.
"Very surprised that they made their way all the way here. I hope that they're happy, and they are being well-treated as visitors,” Chason said with a laugh.
The 11 yellowtail jacks who came through the quarantine period were put on display in a large tank that also holds numerous sharks, which might not seem very nice. Mochon Collura said with a smile that the sharks are well fed by the aquarium staff to curb their appetite for the foreign fish.
Did the West Coast dodge a bullet?
Government agencies and marine biologists up and down the West Coast continue to watch out for more tsunami debris and hitchhikers. The 2011 tsunami washed millions of tons of debris out to sea, some of which is still floating around the Pacific Ocean today. Drifting tsunami wreckage began washing up on West Coast beaches in 2012.
John Chapman, an aquatic invasive species expert at Oregon State University, said Pacific Northwest coastal waters are probably too cold for the fish the aquarium put on display to reproduce. But there are lots of other potential colonists that worry him.
"Yeah, there are real bad characters in that debris,” Chapman said.
That list includes sea stars, seaweeds and parasites that could displace native species. Fortunately, the volume of suspected tsunami debris washing up on our shores has tailed off in past year. What's left out there is getting harder to distinguish from all of the other trash in the ocean.
Chapman said it appears we lucked out.
"We don't have the final answer that we have dodged a bullet. We don't know that yet for sure,” Chapman said. “But I think yeah, as a rough estimate maybe we did."
Looking out for other invaders
The caveat is that it sometimes it takes a long time for an invader to become established. So the marine scientists will keep looking. One of the main methods of surveillance is to lower metal or plastic disks in the water to see what grow on them.
National Oceanic and Atmospheric Administration Marine Debris Program Director Nancy Wallace said these disks are known as "fouling panels." They generally sit out for 1-3 months before being hauled up and scrutinized for unwelcome critters and organisms. Wallace said hundreds of fouling panels have been deployed along the coast from California to Alaska. In addition, trained observers are making periodic checks for sea life that is out of place on the undersides of coastal docks and pilings.
The Japanese government donated $3 million over three years (2014-17) to support debris dispersal modeling and coastal monitoring around the Pacific Rim.
"The government of Japan was unbelievably generous," Wallace said in an interview with public radio.
Non-native fish were also found alive inside one previous tsunami debris wreck, which washed ashore in southwest Washington in 2013. Chapman recalled that five knifejaws were found in the live bait well of that fishing skiff. The aquarium in Seaside, Oregon put one of those knifejaws on public display late in 2013, while the others were euthanized.