Using LED lighting to improve quality of marbled sole

Marbled sole is a major fish species caught in Tokyo Bay. However, due to a decline in resources, Chiba Prefectural Fisheries Research Center, Seed Production Research Laboratory, Futtsu Sea Farming Section releases marbled sole fry into the Bay.

When marbled sole is kept in tanks, the fish bite each other’s tails off. As well as being a possible cause of disease, this could result in the fish losing their ability to swim. This behavior is thought to be due to stress, but it was found that dim green LED light can reduce that stress. Therefore, the Futtsu Sea Farming Section is conducting research to support fisheries by lighting the tanks with LEDs to curb that biting behavior, thus improving the quality of the young fish to be released.

Other research institutes have demonstrated that shining green light onto marbled sole stimulates their appetite and increases their feeding activity, which results in faster growth. The Center hopes to confirm this growth promotion effect and to stabilize and improve efficiency of egg and hatchling production.

Future plans being considered include also replacing operational lighting with LED lights, changing the wavelength by modulating the light, and varying the light according to the species and growth stage of the fish in the tanks.

21,000 marbled sole fry that had grown to 22 mm at the time of the interview continue to grow healthily in the 20,000-liter tank.