The effects of prolonged “bleaching” on the tissue biomass and reproduction of the reef coral Montastrea annularis

Colonies of Montastrea annularis from Carysfort Reef, Florida, that remained bleached seven months after the 1987 Caribbean bleaching event were studied to determine the long term effects of bleaching on coral physiology. Two types of bleached colonies were found: colonies with low numbers of zooxanthellae with normal pigment content, and a colony with high densities of lowpigment zooxanthellae. In both types, the zooxanthellae had an abnormal distribution within polyp tissues: highest densities were observed in basal endoderm and in mesenteries where zooxanthellae are not normally found. Bleached corals had 30% less tissue carbon and 44% less tissue nitrogen biomass per skeletal surface area, but the same tissue C:N ratio as other colonies that either did not bleach (normal) or that bleached and regained their zooxanthellae (recovered). Bleached corals were not able to complete gametogenesis during the reproductive season following the bleaching, while recovered corals were able to follow a normal gametogenic cycle. It appears that bleached corals were able to survive the prolonged period without nutritional contribution from their zooxanthellae by consuming their own structural materials for maintenance, but then, did not have the resources necessary for reproduction. The recovered corals, on the other hand, must have regained their zooxanthellae soon after the bleaching event since neither their tissue biomass nor their ability to reproduce were impaired.

[1]  G. F. Humphrey,et al.  New spectrophotometric equations for determining chlorophylls a, b, c1 and c2 in higher plants, algae and natural phytoplankton , 1975 .

[2]  L. Muscatine,et al.  Reef Corals: Mutualistic Symbioses Adapted to Nutrient-Poor Environments , 1977 .

[3]  A. Szmant.  Reproductive ecology of Caribbean reef corals , 1986, Coral Reefs.

[4]  P. Glynn,et al.  Lipid decline in stressed corals and their crustacean symbionts , 1985 .

[5]  I. Goodbody.  Mass Mortality of a Marine Fauna Following Tropical Rains , 1961 .

[6]  D. Wethey,et al.  Habitat-Related Patterns of Productivity of the Foliaceous Reef Coral, Pavona Praetorta Dana , 1976 .

[7]  C. Holt,et al.  Transfer of photosynthetic products from zooxanthellae to coelenterate hosts. , 1968 .

[8]  M. Pilson,et al.  The effects of feeding frequency and symbiosis with zooxanthellae on the biochemical composition of Astrangia Danae Milne Edwards & Haime 1849 , 1980 .

[9]  P. Glynn.  Widespread Coral Mortality and the 1982–83 El Niño Warming Event , 1984, Environmental Conservation.

[10]  Paul G. Falkowski,et al.  Fate of photosynthetic fixed carbon in light- and shade-adapted colonies of the symbiotic coral Stylophora pistillata , 1984, Proceedings of the Royal Society of London. Series B. Biological Sciences.

[11]  L. Muscatine.  Glycerol Excretion by Symbiotic Algae from Corals and Tridacna and Its Control by the Host , 1967, Science.

[12]  L. Muscatine,et al.  ASSIMILATION OF PHOTOSYNTHETIC PRODUCTS OF ZOOXANTHELLAE BY A REEF CORAL. , 1969, The Biological bulletin.

[13]  L. Muscatine,et al.  Estimating the daily contribution of carbon from zooxanthellae to coral animal respiration1 , 1981 .

[14]  W. Wiebe,et al.  METHOD FOR DETERMINATION OF CORAL TISSUE BIOMASS AND COMPOSITION1 , 1970 .

[15]  C. Hadlai Hull,et al.  SPSS update: New procedures and facilities for releases 7 and 8 , 1979 .

[16]  T. Goreau.  Mass Expulsion of Zooxanthellae from Jamaican Reef Communities after Hurricane Flora , 1964, Science.

[17]  R. Dodge,et al.  Changes in pigmentation associated with the bleaching of stony corals , 1989 .

[18]  J. Battey,et al.  A reevaluation of the role of glycerol in carbon translocation in zooxanthellae-coelenterate symbiosis , 1984 .

[19]  A. Szmant-Froelich,et al.  Sexual reproduction of Favia fragum (ESPER): lunar patterns of gametogenesis, embryogenesis and planulation in Puerto Rico , 1986 .

[20]  J. Marsh,et al.  Primary productivity of reef-building calcareous red algae , 1970 .

[21]  O. Hoegh‐Guldberg,et al.  The Effect of Sudden Changes in Temperature, Light and Salinity On the Population-Density and Export of Zooxanthellae From the Reef Corals Stylophora-Pistillata Esper and Seriatopora-Hystrix Dana , 1989 .

[22]  P. Glynn.  Extensive ‘Bleaching’ and Death of Reef Corals on the Pacific Coast of Panamá , 1983, Environmental Conservation.

[23]  E. H. Williams,et al.  Mass bleachings on atlantic coral reefs. , 1987, Science.

[24]  Lee G Luna,et al.  Manual of histologic staining methods of the Armed forces institute of pathology , 1968 .

[25]  L. Fitzgerald,et al.  Nitrogen excretion and O:N ratios in reef corals: Evidence for conservation of nitrogen , 1990 .