A Novel Approach to Aquaculture
Diet books often warn against eating at night due to potential weight gain. However, a researcher in Nagasaki, Japan, is turning this principle on its head to raise fatty fish in shorter periods.
Professor Katsuya Hirasaka, a chrono-nutrition expert at Nagasaki University's Faculty of Fisheries, is leading this unconventional study. Chrono-nutrition focuses on the timing of food intake, unlike conventional nutrition studies that emphasize what and how much is consumed.
Inspired by athletes who consume protein at breakfast for muscle building, Hirasaka is applying the same approach to fish. He began demonstration tests at the Nagasaki Kakuyo High School's fisheries training facility in 2022, utilizing large seawater tanks and enlisting the help of 11 fisheries club members.
The students actively participated in feeding the fish and measuring their growth, gaining valuable hands-on experience in university-level research. "The study was fun and gave me the feel of what it would be like to be in a university," shared Kai Yamaguchi, a third-year student.
In 2023, Hirasaka compared two groups of white trevally, one fed at 8 am and the other at 7 pm. After a month, the night-fed fish had significantly higher levels of neutral fat in their blood and muscles, resulting in a richer flavor.
Analysis suggests that white trevally have a 24-hour biological clock activated by morning light. Hirasaka believes the increased fat in the night-fed fish is due to a metabolic disorder caused by disrupting their biological rhythm.
This research could have broader implications for the "Japan Buri" project, which aims to breed yellowtail for overseas export. Hirasaka's approach, relying solely on natural processes, could be more appealing to consumers than methods involving genetic modification or drugs.
By harnessing the power of chrono-nutrition, Hirasaka's innovative study paves the way for a more efficient and sustainable approach to aquaculture, potentially revolutionizing the way we raise and consume fish.