In a 31 July press release, Japan’s Fisheries Research and Education Agency reported a poor outlook for Pacific saury for the August to December 2020 season.
The fishing takes place along the Pacific coast of Hokkaido and northeast Honshu Islands. The number and weight of individual one-year-old fish are both expected to be lower than last year, the agency said. One-year-old fish had body lengths of 27 centimeters at the time of the survey and are expected to reach 29 centimeters in August.
A surface trawl catch test is conducted every year from June to July. Conventionally, the survey is conducted with two survey vessels, but this year, one survey vessel could not participate due to the outbreak of COVID-19, so the survey area was reduced, researchers noted. As a result, there is less survey result information that forms the basis of the forecast than usual.
Chinese and Taiwanese vessels concentrate at the edge of Japan’s exclusive economic zone. During surveys, many foreign saury fishing vessels were observed between latitudes 163 and 166 degrees, and the agency assumes that the eastern area is fished out.
Off Hokkaido, the cold Oyashio Current coming from the north collides with the warm Kuroshio Current from the south near Hokkaido. When the two currents collide, the Oyashio Current divides, with the first branch hugging the coast and the second veering off to the west.
When, as is occurring this year, large numbers of sardines and mackerel are found in the first branch of the Oyashio Current, the saury tend to stick to the second branch. As such, this year, it is believed that the schools of fish will move southward along the second branch of Oyashio Current, which will run far offshore, and very few fish will follow the first branch of the current close along the eastern coast of Hokkaido. The fishing grounds at the time large-scale fishing begins in late August will be dispersed in waters north of Russian-controlled Etorofu Island, and the open sea off the eastern coast of Hokkaido.
The school will move into the Sanriku area (Aomori, Iwate, and parts of Miyagi Prefecture) later than usual, arriving in late October, the agency said.
Photo courtesy of Chris Loew/SeafoodSource
