Resilience of coral communities under the global climate change: supply of coral larvae from Kerama Islands to Okinawa Island, and recovery of coral communities in Okinawa I

1. 实地研究表明，喀喇玛群岛的珊瑚种群是冲绳岛产卵珊瑚的幼虫来源；在冲绳岛的珊瑚礁上，产卵珊瑚的增加更大，那里离喀喇玛岛更近。相比之下，喀喇昆山提供的幼虫很少。1 .在孕育的珊瑚中；在1998年大规模珊瑚白化之后，冲绳岛有大量的产卵珊瑚（主要是acroporids），但大多数新招募的珊瑚在大多数珊瑚礁上都无法生存。被吃珊瑚的海星（Acanthaster planci）捕食导致的死亡是检测到的最大死亡因素。因此，珊瑚群落的恢复是非常有限的，就珊瑚礁的数量而言，冲绳I.；2006年，在10%的研究地点（n=18），珊瑚覆盖率达到30%。3 .根据长期监测对珊瑚覆盖变化的分析表明，在过去25年中，位于冲绳1号岛北部的濑子子1号附近珊瑚群落的恢复潜力大大下降。由于喀喇玛岛成年珊瑚群的减少，冲绳岛的珊瑚招募急剧减少。在2002年之后，由于被赶出制动的A. planci捕食。浮游期较长的拟肢珊瑚幼虫的扩散距离被限制在亲本群落200公里以内。与大型藻类接触会降低鹿角珊瑚的生长速度和繁殖力。与巨藻接触的珊瑚消耗资源用于修复巨藻所造成的损伤，剩余少量资源用于生长和繁殖。

1. Coral populations at Kerama Islands are shown to be larval sources for Okinawa Island in spawning corals from the field study; recruitment of spawning corals was greater on reefs in Okinawa I. where closer to Kerama Is. In contrast, very little larvae were supplied from Kerama Is. to Okinawa I. in brooding corals.2. There was a large recruitment of spawning corals (mainly acroporids) in Okinawa I. after the mass coral bleaching in 1998, but most of the recruits did not survive on most reefs. Mortality duet to predation by the coral eating starfish, Acanthaster planci, was greatest of detected mortality factors. As a result, recovery of coral communities was very limited in terms of number of reefs in Okinawa I.; coral cover reached 30% at 10% of the study sites (n=18) in 2006.3. Analysis of change in coral cover from long-term monitoring revealed that recovery potential of coral communities had been much declined around Sesoko I., which is located at northern part of Okinawa I., in the last 25 years.4. Coral recruitment in Okinawa I. was drastically decreased by reduction of adult coral colonies at Kerama Is. due to predation by out-braking A. planci after 2002.5. Dispersal distance of acroporid corals that have long planktonic period as larvae was suggested to be limited within 200 km from parent colonies.6. Contact with macroalgae decreased growth rate and fecundity of Acropora corals. The corals with contact with macroalgae appear to consume their resource for repairing injury caused by the contact, remaining small amount of resource for growth and reproduction.