SAPPORO – Ryotaro Ishida, a 44-year-old fishery researcher, has recently succeeded in mass-farming “shishamo,” a rare saltwater fish that lives only in waters around Hokkaido.

Ishida, who works for the prefectural Mariculture Fisheries Research Institute in Muroran, said it is probably the first time shishamo have been farmed successfully in Japan. What is currently sold as shishamo in Japan is mostly another fish called capelin, mainly imported from Canada and Alaska.

As he watched about 1,500 farmed shishamo swim in a tank, he said, “I thought they would swim on the surface or bottom of the sea, and this is a view that we wouldn’t have been able to see if we hadn’t succeeded in mass-producing them.”

Ishida, who started studying the fish two years ago, said he will use the specimens to study the ecology of the species as little is known about the juveniles. He also hopes to find out why catches have plunged in recent years.

Ishida’s team used about 12,500 shishamo hatched artificially in fresh water for the project, dividing them into groups and raising them in different temperatures with different food to find the best conditions for raising them in seawater.