Divers Attempt Underwater Coral Transplant In Japan
Divers below the waves of Sekisei Lagoon, Japan are hard at work with compressed air drills in hand and hopes of bringing new life to Japan’s largest coral reef near the southern end of the Okinawa chain of islands.
With revolutionary new technology and a substantial amount of taxpayer money, the Japanese government is hoping to combat what has been previously reported to be a 90 percent reduction of coral around Okinawa’s islands, according to the New York Times.
Marine biologists told the Times that the project is one of the largest coral restoration projects in the world. Biologists also hope to learn lessons during the project that will allow them to achieve similar goals in other parts of the world where reefs are endanger of being killed off due to a combination of overfishing, pollution and global warming.
Project workers told the Times that the project is being used as “a test bed for new techniques that they hope will one day make transplanting coral in the sea as routine as raising tree saplings on land.”
“We have been replanting forests for 4,000 years, but we are only just now learning how to revive a coral reef,” said Mineo Okamoto, a marine biologist at Tokyo University of Marine Science and Technology, who has led development of the palm-size ceramic discs.
“We finally have the technology.”
But some are skeptical about the project and are concerned it could be a waste of time and resources. In their opinion, the new transplants are not the solution to the problem. They say the problems such as chemical runoff and coastal redevelopment must first be addressed in order to make an impact on the dying reefs.
The project is now in its fourth year and, so far, some 13,000 pieces of coral have been planted at a cost of nearly $2 million, Hajime Hirosawa, a preservation officer at the Environment Ministry who helps oversee the transplanting, told the New York Times.
But the project is unable to fully address the tens of million of pieces that would need to be transplanted in the region, he said. Additionally, survival rates of new coral sprigs have been low ““ with only about a third of those transplanted in 2005 having survived.
But Hirosawa and others point to increased understanding of new techniques to help improve survival rates.
For example, divers have learned to place new coral sprigs on more protected vertical reefs rather than on flat sea bottoms, where they are in danger of being broken off by surface waves.
The current process involves breaking off pieces of adult coral and transplanting them on another location on the reef. But this can create issues because the new pieces share the host’s DNA, causing the reef to have a less healthy gene pool.
The Japanese technique involves stacking discs underwater for 18 months near a healthy reef, which allows the coral larvae to naturally grow on the ceramic discs.
“Japan’s methods are expensive and labor intensive, but they also bring more genetic diversity and thus healthy reefs,” said Baruch Rinkevich, a specialist in coral transplantation at Israel’s National Institute of Oceanography in Haifa.
“Saving the reef is not something that we can do in three to four years,” said Hirosawa. “but more like 30 to 40 years.”
“This is absolutely worth doing,” one of the team’s divers, Ryo Isobe, 26, told the New York Times.
“When I think of how colorful these reefs used to be, I know we need to do all we can.”
—
On the Net: