Mackerel farming supports sustainability

MITO, Japan >> Ibaraki prefecture is Japan’s largest source of caught mackerel, and the Ibaraki government wants to make fish farming a sustainable industry that future generations can inherit. The prefecture has been conducting an experiment in which technology, including artificial intelligence, is used for farming mackerel. Students at a local high school are working with the government on management of fish farming pens.

The project aims to build a system utilizing underwater cameras and other devices to monitor the condition of fish and water temperature, while an AI system controls feeding. If all goes well, Ibaraki will ship out the farmed fish to markets in the fall.

Cutting costs

Ibaraki seashores curve along the Pacific Ocean and are easily affected by waves, making them a challenging area for fish farming.

But one evening in mid-January, at the Nakaminato fishing port in Hitachinaka, three members of the Ibaraki Prefectural Kaiyo High School fisheries club prepared to feed fish. The students stood at a 16-by-16-foot farming pen, maneuvered a 44-pound bag of feed and inserted the fish food into a feeding machine.

Their work was part of Ibaraki’s effort to raise 10,000 baby mackerel that last fall were about 6 inches long and weighed about 1.7 ounces.

“This is a (valuable) experience for me as I can get involved in an activity that is (technologically) advanced,” said Ryoma Orikasa, 17, a third-year student of the high school. “I feel rewarded when I see the fish growing … little by little.”

Ibaraki hopes to demonstrate the feasibility of an AI-operated feeding system, which would figure out the proper amount of feed to disperse and the proper intervals between feedings.

Reducing leftover feed will both cut costs and contribute to sustaining sea environments.

Six members of the high school club work on the project four times weekly, ensuring the amount of feed is correct in areas where the camera has blind spots and providing data about the mackerel to the government.

“I want to (gain) experiences and utilize them in the future,” said third-year student Reon Uchikoshi, who planned to join a fish farming company this spring.

Served raw

According to 2021 national statistics, Ibaraki caught 73,800 tons of mackerel, the largest amount nationwide.

But in recent years, with the catch of mackerel and salmon down nationwide, the prefecture was motivated to gain proficiency in fish farming to enable stable supplies into the future.

Much of the wild mackerel caught in Ibaraki has been shipped as frozen or canned food to avoid the risk of parasites. But the prefectural government has its sights set on raw mackerel dishes made with its farmed mackerel raised on feed.

By late February the farmed mackerel had grown to about 8 inches long, and are now expected to grow to about 12 inches, a size suitable for harvesting, within a year.

Ibaraki will ship the fish on a trial basis in the fall, through a company in Yokohama that has a nationwide sales network, to determine the farm’s profitability.