Ecology of a caribbean coral reef. The Porites reef-flat biotope: Part I. Meteorology and hydrography

Observations on certain conditions of the physical environment and plankton ecology of a Caribbean coral reef form the subjects of a two-part study. Here, physical factors are considered, with special attention directed to their influence on the Porites reef-flat biotope. Meteorologic (temperature, precipitation, wind) and hydrographic (temperature, salinity, tide, sea level, current) conditions are examined in order to determine their influence on water movement over the reef and correlation with seasonal variations in plankton abundance. Shoal-water circulation is characterized with reference to patterns of movement, origin, and volume flow. A relationship between wind velocity and direction to volume flow is examined in order to describe the interaction of these parameters. The effects of low tidal exposures and storms on the dominant coral species Porites furcata Lamarck are also examined. Observed mortalities and physical alterations due to these factors are shown to be significant, resulting in relatively rapid modifications of the reef-flat habitat. A chief overall objective of this study is to obtain a quantitative assessment of drifting net plankton crossing the reef-flat environment, and to evaluate its contribution as a food source to the shoal-reef biota. Integration of the physical observations with the plankton ecology will form the subject of a forthcoming publication.