Japanese researchers have discovered what they say is the world’s northernmost coral reef off the coast of Tsushima Island in Japan at 34 degrees North, according to a paper published in the journal Geology. The reef was found in cold water and is noteworthy in that most coral reefs are found in warmer waters of at least 64 degrees Fahrenheit. The waters where this reef is located are 55 degrees Fahrenheit. Researcher Hiroya Yamano writes in the journal Geology that the newly discovered reef is completely different in look than reefs that are typically found in warmer waters.
Yamano led a team of researchers in the discovery of the reef, conducting interviews with the locals and poring over old manuscripts that led to the discovery. The reef, estimated to be 4,300 years old, was found within the bays of Tsushima and Iki Islands, in cold waters that are turbid and cloudy.
The corals were not of the Acropora genus, which comprises a majority of corals throughout the world, but were rather of the genus Favia, which is a brown coral that Yamano says can better adapt to the cold and turbid waters of Tsushima Island’s bays. Yamano suspects that the Tsushima Current, a warm water current that flows along the northwestern coast of Japan’s islands, and Asian monsoons brought coral larvae north to the bays of Tsushima and Iki Islands. The full abstract can be found here.