Zoom Up / Fishermen, scientists confront eel problem

Fishermen wield nets in the sea to catch glass eels in Osaki, Kagoshima Prefecture, on Feb. 13. They rarely saw any that night, even when they put their faces close to the water to look for them. A 75-year-old fisherman, who said he has been fishing for glass eels for about 40 years, said, "We used to continue fishing for glass eels until the morning, but now, many fishermen quit and go home after a short time." (Credit: The Yomiuri Shimbun)

Off a dark coast near the mouth of the Hishidagawa river in Osaki, Kagoshima Prefecture, countless headlamps glittered and fine-mesh fishing nets fluttered above the cold sea shoals. Fishermen waded through waist-deep water as they carefully looked into their nets, only to lower them once more.

"We've been fishing for glass eels for two hours, but have only caught a few," one fisherman said. "I've never been in a situation like this."

Catches of glass eel, or juvenile Japanese eel, have reached critical lows across the nation. In Kagoshima Prefecture, a major eel production area, the total amount of glass eels caught in the 75 days from Dec. 10 -- the beginning of this fishing season -- was 19.5 percent of that a year earlier.

Hirofumi Makihara stands in an empty aquaculture pond in Higashikushira, Kagoshima Prefecture. According to Makihara, some eel farmers cannot procure any glass eels this season. Makihara began raising catfish out of fear he might not be able to continue eel farming, and ships his products to supermarkets and other outlets across the nation. (Credit: The Yomiuri Shimbun)

Fluctuations in the north-flowing Kuroshio current in the Pacific Ocean are cited as a reason for the poor catches, but precise causes have yet to be determined.

Hirofumi Makihara, 50, an eel farmer in Higashikushira, Kagoshima Prefecture, purchased 20 kilograms of glass eels for about 4 million yen per kilogram. He said he had never seen such a high price.

"Even if I work very hard to raise them [into marketable adult eels], I'm not sure whether I can make a profit," Makihara said.

Eel larvae are grown at the Shibushi Laboratory of the National Research Institute of Aquaculture, which is run by the Japan Fisheries Research and Education Agency, in Shibushi, Kagoshima Prefecture. The composition of feed and other conditions differ in each tank, so researchers can study how to most efficiently raise glass eels. (Credit: The Yomiuri Shimbun)

Seven of his 10 aquaculture ponds are not filled with water. After he ships the eels he is currently raising, two more ponds will empty. In 2014, he also began cultivating catfish.

At the Shibushi Laboratory of the National Research Institute of Aquaculture, which is run by the Japan Fisheries Research and Education Agency, about 1 million artificially hatched glass eel larvae are being raised. The laboratory is located in Shibushi, Kagoshima Prefecture.

There are many aspects that remain mysterious about the ecology of Japanese eels, such as their spawning routes and what they eat. However, the institute succeeded in farm-raising eels through their complete life cycle in 2010 -- an achievement unprecedented in the world -- and is conducting a study for their commercialization.

Eel larvae about 80 days after they artificially hatched. The larvae develop into glass eels 200 to 300 days after they are born. (Credit: The Yomiuri Shimbun)

"There are still a number of problems such as the survival rate and costs, but we'll work toward the mass production of the eels," Hitoshi Imaizumi, 57, a researcher at the institute, said with resolve.

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