Ocean warming is usually associated with the destruction of coral reefs, but in Japan climate change seems to be giving coral a major boost.
Environmentalists might celebrate but not everybody is happy about the situation, as expanding coral colonies replace the seaweed beds that once provided a habitat for commercially valued marine life such as abalone, anchovies and bass.
Scuba divers have reported that tropical Acropora hard corals, mainly A solitaryensis, are increasing rapidly as seaweed beds disappear, and the fishing community is bemoaning its fate.
The effect, spotlighted in the sea south of Tokyo Bay in a report in Kyodo News, is firmly attributed to climate change in the north-west Pacific.
The seaweed beds have been disappearing over the past 12 years, as sea temperatures have remained above 15 degrees C even in winter, and reached record levels last year. At times they now exceed 28 degrees C.