The population of mudskippers in Kyushu's Ariake Sea has increased eightfold in the first survey in 16 years, as the fish have been able to easily survive mild winters amid rising temperatures, a research institute said Wednesday.

Mudskippers, known as "mutsugoro," live in mud flats of the Ariake and Yatsushiro seas in Kyushu. Their population has been declining since 1970 due to environmental change and overfishing, prompting the Environment Ministry to designate them in February as a species facing extinction in the near future.

But the population uptick was confirmed in a visual examination at 76 observation points last August by the institute in Saga Prefecture, which compared the latest data with data from August 1996.

Falling demand for meals featuring mudskippers, as well as conservation measures, have also contributed to the increase, institute officials said.