Coral reefs of north Jamaica, normally sheltered, were severely damaged by Hurricane Allen, the strongest Caribbean hurricane of this century. Immediate studies were made at Discovery Bay, where reef populations were already known in some detail. Data are presented to show how damage varied with the position and orientation of the substraturn and with the shape, size, and mechanical properties of exposed organisms. Data collected over succeeding weeks showed striking differences in the ability of organisms to heal and survive.

The timing of reproduction was investigated in 15 colonies of Montastraea annularis located on the Port Royal Cays, Jamaica. Spawning occurred between Days 6 and 8 after August's and/or September's full moon. In the 14 wk prior to spawning, mean total gonad size increased from 0.30 ± 0.17 to 34.38 ± 13.20% of the polyp cross-sectional area. Gonad size was significantly correlated with temperature and light intensity, but was not correlated with photoperiod or rainfall. Spawning occurred in the month prior to the period of heaviest rainfall, when temperatures were at their maximum. A meta-analysis of spawning time and climatic conditions at 19 other geographical locations also showed that spawning occurs in those periods without heavy rainfall in which temperatures are warmest. The data presented here suggest that temperature is not the only environmental variable controlling the annual timing of coral spawning. Rather, the time of coral spawning is controlled by a combination of temperature and rainfall.

Polyp tissue depth, skeletal extension rate, reproduction and density band formation were studied in 15 colonies of Montastraea annularis from October 1994 to September 1997 as part of a long-term field study. With the commencement of a bleaching event in September 1995, the effects of bleaching on these biological parameters were examined. Bleaching affected all the parameters investigated, but the speed of recovery of each parameter to pre-bleaching values differed. Tissue depth recovered the fastest, within 4 to 8 wk of regaining normal pigmentation. Once pigmentation and tissue depth had recovered, skeletal growth resumed at its pre-bleaching rate. Reproduction took the longest to recover and reproductive failure occurred in severely bleached colonies 1 yr after bleaching. Even after 2 yr, reproductive output remained reduced in previously bleached colonies when compared with previously unbleached ones, although all colonies had successfully completed gametogenesis and spawning. Among the reproductive parameters measured, gonad size recovered faster than the number of gonads per polyp (i.e. polyps produced a smaller number of full-sized gonads 2 yr after bleaching). In all colonies, bleached and unbleached, the 1995 annual high-density (HD) band, which formed at the time of the bleaching event, appeared more prominent and in some cases wider than the HD bands for the years that preceded and succeeded bleaching. Bleaching reduced skeletal extension rate, and the HD band that formed at the time of the bleaching event was most pronounced in colonies in which skeletal extension rate was reduced for the longest period of time (i.e. severely bleached colonies). In 1996, the year following the bleaching event, colonies that did not complete gametogenesis (i.e. severely bleached colonies) produced no distinct HD band, while those that completed gametogenesis (i.e. mildly bleached colonies) produced a distinct HD band. These findings suggest that an inverse relationship between skeletal extension rate and HD band prominence may occur in Montastraea annularis, and that the failure of severely bleached colonies to produce a HD band in 1996 might be related, not to bleaching, but rather to the lack of gonad development and spawning in these colonies. KEY WORDS: Montastraea annularis · Coral bleaching · Skeletal density banding · Skeletal extension rate · Reproduction · Polyp tissue depth Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 235: [93][94][95][96][97][98][99][100][101][102] 2002 by the bacterium Vibrio shiloi at elevated sea temperatures (Kushmaro et al. 1996). The large-scale, mass bleaching events, which have occurred around the world in the last 20 yr (i.e. in 1979-1980, 1982-1983, 1986-1987, 1991, 1995-1996 and 1997-1998), have been linked to increases in seawater temperature resulting from increased El Niño-Southern Oscillation activity and global warming (e.g. Williams & BunkleyWilliams 1990, Glynn 1993, Brown 1997, Huppert & Stone 1998.Few stu...

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