For half a century, Takeo Nakajo has been catching katsuo, or skipjack tuna indispensable in Japanese cuisine whether eaten raw, dried or used as a base for the broth.
But he and other fishermen in Kure, in Kochi prefecture in southwest Japan, have seen something worrying in the past two years an unprecedented number of unusually fatty katsuo.
While heavier katsuo means more money, locals and experts say it indicates climate change and a risk for katsuo numbers already under threat due to growing demand and overfishing.
“The fatty katsuo must have something to do with the water temperature,” said the