Effects of eutrophication on reef-building corals

摘要: The sexual reproduction of Porites porites (Pallas), a shallow water hermatypic coral, was studied over one-year period (June, 1982 to June, 1983) on three fringing reef complexes lying along an eutrophication gradient the west coast Barbados, West Indies. data suggest that P. is gonochoric species with brooding mode reproduction, but low incidence (2.7%) hermaphroditism detected in population sampled from subjected urban and industrial pollution. Gonadal development occurs within mesenteries between retractor muscles mesenterial filaments. Gametogenesis during nine ten months year, peak reproductive activity occurring predominantly fall winter (November January). therefore loosely synchronized colonies; however, gonads all stages were present colonies throughout season. season two populations polluted reefs began one earlier than less reef. simultaneous presence ova larvae colony November April suggests may be released repeatedly extended breeding No correlation found average number polyp size. However, gonad index (average based sum male female gonads) showed inverse relationship environmental variables. It suggested zooxanthellae maturing play important role success porites. reduction photosynthesis through reduced light levels significantly lower energy available photosynthates and/or embryos, thus depressing larval maturation. Coral contained numbers 2: 1 sex ratio observed result rapid asexual (fragmentation), indicating influenced by conditions.