Ecological aspects of coral transplantation
1999
Yap, H.T. (Philippines Univ. Diliman, Diliman, Quezon City (Philippines). Marine Science Inst.)
The growth and mortality of transplants of two species of scleractinian corals, Porites cylindrica and Porites (Synaraea) rus, were monitored over 16 months. Transplants were in two sizes (nubbin and fist-sized) and deployed at two depths (1 and 10 m). Specimens at the shallow depth had more pronounced growth than the deeper ones. Light had significant effects on coral growth while temperature, salinity, water movement and sedimentation did not. Smaller corals consistently registered greater percentage increases in size as compared to the larger ones. Small transplants of P. cylindrica showed higher percentage growth rates than those of P. rus. Contrary to expectations, there were no differences in transplant mortality due to size. Over the course of the experiment, mortality was generally confined to the shallow depth. It was brought about either by algal competition or by strong water movement. The above trends were confirmed by measurements of linear skeletal extension after a number of months measured from a baseline marked with Alizarin Red S.P. cylindrica transplants grew faster than P. rus transplants exhibiting intrinsic differences in growth potential. Shallow transplants of both species grew less than the control colonies at the same depth, probably due to rechannelling of energy for tissue regeneration. Shallow transplants grew faster than deep transplants which could be explained by the greater light intensities available for photosynthesis which in turn promoted coral calcification. Linear growth rates of shallow transplants nearly approximated those of wild recruits of Pocillopora damicornis. This indicated that transplantation-associated trauma was eventually overcome so that growth resumed at rates within the range observed for naturally established colonies
显示更多 [+] 显示较少 [-]