Physiological and ecological aspects of coral transplantation

Abstract

The growth and mortality of transplants of two species of scleractinian corals, Porites cylindrica Dana and P. rus Forskal (1775), were monitored over 16 months in a reef in the northwestern Philippines. Transplants were in two sizes (nubbin, ∼8 cm in length; and fist-sized, ∼8 cm in diameter) and deployed at two depths (1 and 10 m). Specimens at the shallow depth had more rapid growth than the deeper ones. Light had significant effects on coral growth while temperature, salinity, water motion 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.