BackgroundThe rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin.Methodology/Principal FindingsSatellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles.Conclusions/SignificanceThermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.

This paper determines the bioaccumulation and transfer processes of organochlorine pesticides within the stream food web in Guadeloupe (Caribbean). ABSTRACTConcentrations of organochlorine pesticides and stable isotope ratios of nitrogen and carbon were measured in a tropical freshwater ecosystem to evaluate the contamination level of biota and examine the bioaccumulation patterns of pollutants through the food web. Chemical analyses showed a general and heavy contamination of the entire food web. They revealed the strong accumulation of pollutants by juveniles of diadromous fishes and shrimps, as they re-enter the river. The role of ecological factors in the bioaccumulation of pesticides was evaluated. Whereas the most persistent pollutants (chlordecone and monohydro-chlordecone) were related to the organisms diet and habitat, bioaccumulation of β-HCH was only influenced by animal lipid content. The biomagnification potential of chlordecone through the food chain has been demonstrated. It highlighted the importance of trophic transfer in this compound bioaccumulation process. In contrast, bioconcentration by passive diffusion from water seemed to be the main exposure route of biota to β-HCH.

This work was carned out on a fringing reef situated on the leeward coast (North-West) of Reunlon Island (Mascarene Archipelago, Indian Ocean). A boat channel, a compact reef flat and a reef flat with transverse stripes were successively found between shore and reef front. Two structures were defined on the outer reef slope: the coral-built spurs-andgrooves zone (0-20 m) and the lower sloping platform, a volcanlc flagstone with low biogenic coverage (20-30 m). Seawards, thls flagstone is completely covered by a field of free organic nodules. Scleractinlan coral communities were studled with quantitative sampling methods (quadrat and transect techniques) in terms of species composition, zonation and diversity patterns. On the basis of these data, the coral comnlunities were divided into 3 assemblages: ( I ) A community of the boat channel and the compact reef flat. The emersion of this reef flat at low tide induces the development of facies formed by Acropora pharaonis and Pavona divaricata. The reef flat with transverse stripes appears as a transition zone with the second community. (2) A community of the spurs-and-grooves zone of the outer reef slope, divided into 3 subzones. (a) upper level, influenced by strong wave action, characterized by spatlal competition between scleractinian corals and encrusting calcareous algae; (b) intermediate level dominated by a small number of Acropond and Poritid species; (c) lower level, where the decrease in llght intensity reduces the building activity of Scleractinia. (3) A community of the lower part of the outer slope, extending to the nodules field, characterized by settlement of an important number of deep species and by high specles richness. 42 genera and 120 species of Scleractinia reveal a remarkable faunistic richness for the reef studied.

1. Stable isotope analysis, coupled with dietary data from the literature, was used to investigate trophic patterns of freshwater fauna in a tropical stream food web (Guadeloupe, French West Indies). 2. Primary producers (biofilm, algae and plant detritus of terrestrial origin) showed distinct d 13 C signatures, which allowed for a powerful discrimination of carbon sources. Both autochthonous ( 13 C-enriched signatures) and allochthonous ( 13 C-depleted signatures) resources enter the food web. The migrating behaviour of fishes and shrimps between marine and freshwater during their life cycles can be followed by carbon isotopes. Here, shrimp d 13 C signatures were shown to shift from )16& (for juveniles under marine influence) to )24.7& (for adults in freshwater habitats). For resident species, d 13 C values partly reflected the species' habitat preferences along the river continuum: species living in river mouths were 13 C-enriched in comparison with those collected upstream. 3. Nitrogen isotopic ratios were also discriminating and defined three main trophic guilds among consumers. The d 15 N values of herbivores ⁄ detritivores were 5.0-8.4&, omnivores 8.8-10.2& and carnivores 11-12.7&. 4. Mixing model equations were employed to calculate the possible range of contribution made by respective food sources to the diet of each species. The results revealed the importance of omnivorous species and the dependence of riverine biota on terrestrial subsidies, such as leaf detritus and fruits. Finally, the abundance of shrimps and their feeding habits placed in relief their key role in tropical freshwater food webs. Isotopic analysis provides a useful tool for assessing animal feeding patterns.

SynopsisThe relationships existing between the chaetodontid fishes and the surrounding coral communities were investigated in the Gulf of Aqaba. Quantitative data were analysed by a correspondence and a cluster analysis. The results demonstrated a similarity in the spatial distribution of both communities. Significant correlations were found between the density of chaetodontid fishes and the diversity of the coral community as well as the substratum coverage by the coral colonies. The density of exclusive coral browsers was also correlated to the abundance of branching colonies. Among the different genera of branching corals, correlations were significant only for the genus Acropora. These results suggested the existence of strong links between coral and chaetodontid fish assemblages.

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Swamp forest covers c. 2600 ha of coastal wetlands in Guadeloupe. An inventory of all vascular plants was conducted together with a characterization of the main abiotic descriptors within seventeen 10-m × 40-m plots, systematically sampled throughout the forest. Girth at breast height (GBH) was measured for all trees ≥10 cm GBH. Four forest types were discriminated according to pH, clay content and redox potential of the soils. Among the 107 species recorded, lianas and epiphytes were as much represented as tree species (28%). However, no epiphytes were encountered at the canopy level where Pterocarpus officinalis (Papilionaceae) was the evenly dominant tree. Local hummock-hollow topography was responsible for an aggregated distribution of P. officinalis. This species exhibits several adaptative traits which may explain its dominance over all of the lowland swamp forests subjected to permanent waterlogging in the hurricane-prone Caribbean islands.