The recent collapse of a rapid phase-shift reversal on a Jamaican north coast coral reef after the 2005 bleaching event

The community structure of most Caribbean reefs has changed dramatically since the 1980s. Invoking a chemistry analogy, in 1994 Hughes termed the change a "phase shift" to describe the change from a coral dominated habitat to one dominated by macroalga on the north coast of Jamaica over a period of 17 years. The loss of live coral cover is exemplified by the demise of Acropora spp. in Discovery Bay, Jamaica. Dense, monospecific high relief thickets of Acropora palmata (elkhorn coral) and A. cervicornis (staghorn coral) were characteristic of shallow and intermediate depth coral communities in the Caribbean prior to the late 1970s. In the early 1980s, A. cervicornis live coral cover was >21% at several sites around Discovery Bay, by 1987 it had declined to less than 1%. No large population of Acropora reestablished in the vicinity of Discovery Bay for nearly two decades. In 1995, A. cervicornis cover at Dairy Bull Reef (DBR) was only 0.6%. By 2004, A. cervicornis cover had increased to about 10.5% . In 2005, A. cervicornis cover further increased to 44%. This increase in A. cervicornis cover was part of the important "phase shift reversal" reported by Idjadi et al. in 2006. An isolated population of A. cervicornis exhibited similar coral cover at East Rio Bueno (ERB). In 2005, both populations of A. cervicornis bleached; however, the two populations responded differently. The population at DBR was decimated by the bleaching event and the surviving remnants were attacked by Coralliophila. At DBR, cover declined to <0.5% by June 2006. The population at ERB recovered from the bleaching event with little decrease in cover. Coral recruitment was examined over three spawning periods on DBR. Only two Acropora spat recruited to settlement tiles - one in 2003 and one in 2005. Acropora recruitment represented only 0.7% of the total spat recruiting to the tiles during the entire sampling period. Rev. Biol. Trop. 56 (Suppl. 1): 149-159. Epub 2008 May 30.