A hotel operator in northeastern Japan is one of a small number of companies that have launched businesses in depopulated rural areas to farm the much-prized delicacy torafugu, or tiger puffer fish, using tanks filled with hot spring water.
Torafugu, an expensive delicacy in Japan, raised in this manner is free of the toxins that require the fish to be prepared by licensed chefs and also grows much faster than torafugu farmed at sea, the usual method, according to the operator, Akita Kyoei Kanko.
It started offering full-course meals based on the fish, including thin slices of sashimi -- the most popular way of serving torafugu -- to its guests in December.
After purchasing in September 2017 a hotel that had closed more than a decade ago in the town of Shizukuishi, Iwate Prefecture, the company set up 10 tanks that can hold a total of about 10,000 liters of hot spring water.
The company, based in neighboring Akita Prefecture, began farming the fish in February last year, starting with 4,000 juvenile puffers. It said the local hot spring water is rich in minerals and suitable for cultivating this kind of fish.
The warm water helps the puffers to grow even in winter and enables the hotel operator to ship them in about a year, about six months earlier than those farmed in the sea.
It opened the farm with the support of Yumesozo, a company based in landlocked Tochigi Prefecture, north of Tokyo, which invented the technique of cultivating puffers using hot spring water to help revitalize small depopulated towns and villages.
The fish is one of Japan's top delicacies and usually contains a deadly neurotoxin in its liver and other organs.
But the fish farmed by the company at its facility in Shizukuishi is nontoxic as it is not raised on seaweed and shellfish, which are thought to be the origins of the poison.
"Our tiger puffers are as delicious as wild ones," Ritsu Iwamoto, managing director of the hotel operator, said. "We want to develop it as a new local specialty and contribute to reinvigorating northeastern areas in Japan."
Japan has hot spring sources in all 47 prefectures, with the total number standing at more than 27,000 as of fiscal 2016, according to the Environment Ministry.
With franchise contracts with Yumesozo, more than 10 other companies have started using hot spring water to farm torafugu at sites including a former elementary school in Miyazaki Prefecture, southwestern Japan.