Tropical Species Thrive In Warm Water Discharge From Japan Nuke Plant - Beta Test For Warming
Tropical fish and other species were able to colonise a small coastal area in the Sea of Japan thanks to discharges from a nearby nuclear power plant. The findings suggest global warming will drastically alter marine ecosystems around the temperate areas of Japan over the next few decades.
Since 2004, Reiji Masuda at Kyoto University and his colleagues have been carrying out underwater surveys every winter at three coastal sites near Kyoto. One of these sites is warmed by the water used to cool the Takahama nuclear power plant, keeping winter water temperatures around 13.6°C.
There, the divers saw both more fish overall and a greater diversity of species, including tropical ones such as the blue damselfish (Pomacentrus coelestis) and the cutribbon wrasse (Stethojulis interrupta). Tropical invertebrates included the long-spined sea urchin (a species of Diadema). “There were so many sea urchins as they did not have predators,” says Masuda.
These tropical species weren’t seen at the other two sites, even though winter temperatures there were only slightly lower, at 12.3°C and 11.7°C. In February 2012, operations at the nuclear plant were suspended because of the Fukushima disaster. Winter water temperatures at the dive site fell by 3°C to 10.6°C, and the tropical species all disappeared. During surveys soon after the suspension, the divers saw dying fish and sea urchins. In 2017, two of the four units at the nuclear plant restarted, and tropical species are gradually returning.
EDIT
https://www.newscientist.com/article/2242786-a-japanese-nuclear-power-plant-created-a-habitat-for-tropical-fish/