Fishermen's News - The Advocate for the Commercial Fisherman

Invasive Asian Fish Found in Oregon Waters

 

A striped knifejaw, also known as a barred knifejaw or striped beakfish, is native to Japan, China and Korea. Crabbers near Port Orford, Oregon recently hauled in a live one and turned it over to researchers for evaluation. A variety of potentially invasive species of plants and animals have arrived in Washington and Oregon waters and on Pacific Northwest shores at intervals aboard debris swept into the ocean by the 2011 tsunami that washed over part of Japan. Photo courtesy of Oregon State University.

With plenty of flotsam from the 2011 tsunami that wreaked havoc on Japan still marooning itself on Pacific Northwest shores, researchers remain vigilant for the possibility of any invasive species – flora or fauna – that might hitch a ride on or in that flotsam.

That's why a team of scientists from Oregon State University (OSU) and the Oregon Department of Fish and Wildlife (ODFW) are studying an unusual fish – known as a striped knifejaw – recently captured alive in a crab pot near Port Orford, Oregon. Researchers say it's too soon to determine whether or not this native of Japan, China and Korea – also called a barred knifejaw or striped beakfish – is established in Oregon waters, or what effect it might have if it has. Nor are they certain if the fish hitchhiked aboard tsunami-related debris.

"Some association with Japanese tsunami debris is a strong possibility, but we cannot rule out other options, such as the fish being carried over in ballast water of a ship or an aquarium fish being released locally," said John Chapman, aquatic invasive species specialist at OSU's Hatfield Marine Science Center (HMSC) in Newport, Oregon. "But finding a second knifejaw nearly two years after the discovery of (others) in a drifting Japanese boat certainly gets my attention."

Four of five striped knifejaws found alive in a boat from Japan near Long Beach, Washington, in March 2013 were euthanized. One went to the Seaside Aquarium, where Chapman said it's still alive and well.

OSU marine ecologist Jessica Miller examined the four euthanized knifejaws, analyzing their otoliths (ear bones) for clues about their origin.

"The young fish of these species are known to associate with drift and may be attracted to floating marine debris," Miller said. "Japanese tsunami marine debris continues to arrive on beaches in Oregon and Washington – and some debris from Japan (recently) washed up on the southern Oregon coast, so it is not inconceivable that the Port Orford fish was associated with Japanese marine debris."

The fish also calls other parts of Asia and the northwest Hawaiian islands home.

Miller said they have found no evidence that the stripers are successfully reproducing in Oregon waters, despite the fact that the fish extracted from the crab pot is "not a fully grown adult," said Tom Calvanese, an OSU graduate student researcher working with Oregon Sea Grant on the start-up of a new university field station in Port Orford. Calvanese worked with the fisherman who captured the exotic fish in a crab pot between Port Orford and Cape Blanco just off the Elk River in southern Oregon.

"We are fortunate to have this occur in a fishing community that is ocean-aware," he noted. "The fisherman who caught the fish identified it as an exotic, then transported it to shore alive, where the fish buyer was able to care for it. It appeared to be in good shape and was swimming upright, though it had a small cut in its abdomen."

Keith Chandler, director at the Seaside Aquarium suggested feeding it razor clams, which the fish devoured eagerly.

Capture of this unusual immigrant fish provides a learning opportunity for researchers. Steve Rumrill, an ODFW biologist, worked with Calvanese and others to transport the fish to a quarantine facility at HMSC, where OSU's aquatic veterinarian Tim Miller-Morgan of Oregon Sea Grant will oversee its care.

Rumrill said they needed to hold the fish in quarantine until the wound is healed, and to allow "sufficient time to ensure that it is free from any pathogens or parasites that could pose a threat to our native fishes."

OSU and Oregon Sea Grant invasive species expert Sam Chan, who serves as vice-chair of the Oregon Invasive Species Council and has observed striped knifejaws in Japan, estimates the fish is one to two years old, making it unlikely that it started its journey to the Pacific Northwest just after the 2011 tsunami. "A boat could have been milling around Asian waters for the past two or three years, then picked up the fish and ridden the currents over," Chan added. "The big question is – are there more of these?"

Researchers said Oregon Sea Grant – an OSU-based marine research, education and outreach program – would work with Oregon fishermen, crabbers and others to keep a lookout for additional striped knifejaws and any other exotic species. Invasive species that establish themselves in Washington, Oregon or California waters can wreak havoc on native species – commercially viable ones among them – by detrimentally altering their habitats.

Commercial fishermen who believe they have spotted any invasive species should report it at http://www.oregoninvasiveshotline.org, or call 1-866-INVADER FREE.

 
 

Powered by ROAR Online Publication Software from Lions Light Corporation
© Copyright 2017