An experiment using a large aquarium has begun in Hakodate City, Hokkaido, in an attempt to elucidate the detailed mechanism of a phenomenon called "Kuki" in which the sea becomes cloudy after a herd of herring spawns.
"Flocking" is a phenomenon in which a group of female herds lay eggs on coastal seaweed and then the male sperm sperm and the sea becomes cloudy. It was confirmed for the first time.
A research team at Hokkaido University began a full-scale experiment in Hakodate City on the 22nd, using a large aquarium, in an attempt to elucidate the detailed mechanism of the crowd.
In the aquarium, a herd of about 700 herrings from Shibetsu-cho, Hokkaido is bred, and artificial seaweed for laying eggs is installed.
Then, by changing the temperature of the seawater in the aquarium and adjusting the density of the herring herd by increasing or decreasing the amount of seawater, it is necessary to investigate the environment in which spawning is likely to occur.
We also analyze the time when eggs were laid from a small sensor attached to the herring, and hope to use it to predict the resources of herring in the future.
Professor Kazushi Miyashita of the Northern Biosphere Field Science Center, Hokkaido University said, "A lot of herring swarms have been seen recently along the coast of Hokkaido. I would like to clarify the mechanism of how the swarms occur."