The Fisheries Agency will start a project this fiscal year to restore the ailing coral reef around Japan’s southernmost island of Okinotori that many experts fear will be in for further damage due to global warming.
The coral reef forms a natural breakwater protecting the island from erosion, as well as providing habitats for fish and other sea creatures. Due to the ailing coral reef, erosion of the island has already started. The area of the island has been reduced to two sets of islets both several meters wide and long during high tide.
To slow the erosion, Japan has installed wave-dissipating blocks and concrete embankments around the isle in an atoll.
Under the plan, the agency will examine techniques for coral propagation and cultivation in the next three years to draft technical guidelines.
“We hope the guidelines will be useful, not only for coral restoration in other parts of Japan but also for overseas,” an agency official said.
The agency will set up a project center on Aka Island in Okinawa Prefecture to cultivate a coral colony taken from the Okinotori atoll.
The agency plans to let the coral spawn in an aquarium and release the larvae in Okinotori.
The project will be the agency’s first major project to focus on coral cultivation from eggs. So far, propagation has been a well-established method. Only limited experiments have been conducted on cultivating corals from eggs.
Because Okinotori has no nearby islands, it is unlikely the atoll will attract coral larvae from elsewhere, the agency said.
The agency also plans to conduct an experiment in which it encloses areas surrounding the coral with a net so the eggs will settle in the area.
In recent years, coral reefs around the world have been threatened by bleaching believed to be caused by the rise in sea temperatures due to global warming and by an outbreak of crown-of-thorns starfish which eat coral.
The uninhabited tiny isle 1,700 km south of Tokyo has allowed Japan to control a vast exclusive economic zone as large as the entire country. China has claimed it is not an island but a set of rocks.