Ballast Blog – Invader of the Week – Barred Knifejaw

Malin Group Ballast Blog

Five years have passed since the magnitude 9 earthquake struck Japan, unleashing a savage 133-foot high tsunami which claimed the lives of 16,000 people. Upon its retreat, the giant surge of water carried an estimated 5 million tons of debris out to sea – including Japanese docks, ships and household items, which are still arriving along the Pacific coast of the US and Canada five years later.

Over 200 species have hitched a lift across the Pacific Ocean aboard this debris, some of which are becoming a cause for concern among a number of scientists;

There have been four separate findings of barred knifejaws along the Pacific coastline in the US over the past three years – a fish native to Japan. In 2013, a Japanese boat containing barred knifejaws washed ashore in the state of Washington; a second was found in a shipwreck off the coast of California; a third was found trapped in a crab pot in Oregon in 2015. The most recent sighting of the species, in mid-2015, was in a boat tank in Oregon.

Theoretically, the water temperatures where barred knifejaws have been found are too cold for them to spawn. However some scientists speculate that reproductive populations simply haven’t been found yet, and that the barred knifejaws may be cross-breeding with native species. Time will tell whether these aquatic hitch hikers will make it onto the list of marine invasive species wreaking havoc on the ecosystems in which they arrive.

(Picture courtesy of