DEVELOPMENT OF CORAL REEF RESTORATION TECHNOLOGY BY MASS CULTURE, TRANSPORTATION AND SETTLEMENT OF CORAL LARVAE (PART2)

Abstract

We conducted two sets of the experiments on coral recruitment by in situ mass culture, transportation, and release of reef-building coral larvae in Okinawa, Japan in 2002 and 2003. Gametes and embryoswere collected from slick on the sea surface and cultured in floating culture ponds at Akajima untilthe larvae were competent to settle onto a substratum. About 2 and 4 million larvae were transportedby boat to a seeding experimental station at Naha Port, a distance of 50 km east of Akajima in 2002 and 2003 respectively. Divers released the larvae over concrete blocks surrounded by nylon mesh enclosures. The number of polyps settling on the blocks was monitored regularly and compared with a control block outside the enclosures. In 2003, we investigated density of the larvae at each process andprepared hollowed concrete blocks to enhance larval recruitment. As the result, the number of polypsin 2003 increased 2 to 3 times of the 2002. Although it needs improvement, this restoration technology is considered to have reach a satisfactory condition.