Vol. 49 No. 6, 2010

Post-Settlement Survival of Reef-Coral Juveniles in Southern Taiwan

Kum-Ming Kuo and Keryea Soong*

Institute of Marine Biology, National Sun Yat-sen University, Kaohsiung 804 Taiwan

Kum-Ming Kuo and Keryea Soong (2010) Studies of spatiotemporal settlement patterns of reef corals suggest uneven distributions through space and time. Whether the patterns reflect adaptations of early benthic stages or non-adaptive result from processes preceding settlement are not always clear. They, however, may be distinguished by testing how well newly settled juveniles survive in different places and times of the critical initial post-settlement period. Herein, we compared the survival of young coral that had settled in different seasons and in different habitats. Artificial settling plates were deployed at 2 mo intervals in southern Taiwan, and the fate of each naturally settled coral spat was monitored at 2 mo intervals for at least 1 yr after settlement, in 1998-2000. Spats of Pocilloporidae and Porites spp. constituted the majority of coral recruits. Pocilloporids exhibited significant seasonal variations in settlement densities, but poritids showed no such pattern. The probability of pocilloporids surviving an additional 2 mo increased from ~60% at 2 mo old to virtually 100% at 22 mo old. In Porites, the 2 mo survival rates were > 90% in all age groups. Survivorship of pocilloporids and poritids was higher for those that settled in the dry season (Nov., Jan., and Mar.) than those that settled in the wet season (May, July, and Sept.), but no corresponding higher settlement rates were found for either taxon in the dry season. Recruits of both taxa showed greater survivorship when settled on younger than on older plates; however, only pocilloporids preferred young plates for settlement. Spat densities and survivorship rates were both higher at the margins than in the center of plates for both taxa. Thus, the settlement season was not related to higher post-recruitment survival, but spatial variation at settlement was, at least for these 2 taxa.

Key words: Survivorship, Settlement, Reproduction, Recruitment.

*Correspondence: Tel: 886-7-5255109. E-mail:keryea@mail.nsysu.edu.tw