Performance of ecological restoration in an impaired coral reef in the Wuzhizhou Island, Sanya, China

Abstract

Coral restoration is becoming popular to help restoring degraded coral reefs. However, few studies have tried to monitor the long-term recovery of coral reefs, which makes it difficult to assess the performance of the restoration. We monitored the growth of three transplanted Acropora corals and naturally-attached Pocillopora damicornis on artificial reefs (ARs) from October 2014 to September 2018 during which there were several attacks of typhoons. Results show that two staghorn Acropora species had the highest growth rates (11.0–12.1 cm/a), followed by table coral A. divaricate (5.6 cm/a) and P. damicornis (4.8 cm/a). A linear growth pattern was found for the three Acropora species; the pattern gradually slowed in P. damicornis. There was a strong interspecific competition for space among the corals on ARs, and it led to the sharply declined occurrence of slow-growing P. darmicornis colonies in 2017. Coral recovery was successful at the Wuzhizhou Island and quickly increased AR complexity. However, the ARs made of metal frames fail to resist the direct attack from a catastrophic typhoon. Therefore, concrete and environmental-friendly materials should be used in future restoration. This study is the first report on long-term monitoring and assessment of coral reef restoration in China. The results offer future guide of reef restoration for impaired coral reefs in regions easily affected by typhoons.