Some Pacific Ocean corals have migrated north — and done it fast — possibly in response to rising ocean temperatures, Japanese researchers say.
Scientists of the National Institute for Environmental Studies in Tsukuba, Japan, analyzed maps of corals from four time periods starting in the 1930s and found that of nine common species, four had moved northward, and two species even went so far as to move out of the tropics to temperate waters, ScienceNews.org reported Monday.
Marine biologists and fisherman have long suspected this northern migration was taking place.
“There were eyewitness accounts of the occurrence, but the data wasn’t so reliable,” geographer Hiroya Yamano says. “Now we can show very solid evidence.”
The speed of the migration surprised the researchers. Some of the species studied by Yamano migrated as fast as 8.7 miles per year, and in the 80 years since the 1930s maps were published, the fastest have traveled nearly 700 miles.
Placed alongside other studies that show land animals moving north as temperature rises, it’s a strong possibility the corals in this study are moving to fight the heat, John Pandolfi, a marine biologist at the University of Queensland in Brisbane, Australia, says.
Researchers will need to conduct studies on these mobile species in the lab to test whether temperature is truly the driving factor, he says.