Oculina

Abstract: Laboratory aquaria experiments demonstrated that Vibrjo AK-1 caused rapid and extensive bleaching of Oculina patagonica at 29°C slower and less complete bleachmg at 25°C and 2OoC, and no bleaching at 16°C. The effects of temperature on the bacteria-induced bleaching experiments in aquaria were consistent with the natural bleaching of 0. patagonica in the Mediterranean Sea. In sjtu bleaching increased rapidly from late May to September, following the rise of surface seawater temperature, which reaches 29°C in August. During the winter, when the seawater temperature drops to 16'C, most of the bleached coral colonies recovered. Vibrio AK-1 was isolated from all bleached corals examined in the summer, but could not be isolated from healthy (unbleached) corals in the summer or from bleached and unbleached corals in the wlnter. The mechanism by which increased temperature causes the coral bleaching by V ~ b n o AK-l is at present not clear. The bacteria grow in the laboratory relatively rapidly at 16'C (doubling time 2 h), indicating that bacter~al growth is probably not the critical factor We suggest that temperature-regulated factors affecting bacterial virulence may play a role in the bleaching process.

Abstract: We mapped and briefly describe the surficial geology of selected examples of shelfedge reefs (50–120 m deep) of the southeastern United States, which are apparently derived from ancient Pleistocene shorelines and are intermittently distributed throughout the region. These reefs are ecologically significant because they support a diverse array of fish and invertebrate species, and they are the only aggregation spawning sites of gag (Mycteroperca microlepis), scamp (M. phenax), and other economically important reef fish. Our studies on the east Florida shelf in the Experimental Oculina Research Reserve show that extensive damage to the habitat-structuring coral Oculina varicosa has occurred in the past, apparently from trawling and dredging activities of the 1970s and later. On damaged or destroyed Oculina habitat, reef-fish abundance and diversity are low, whereas on intact habitat, reef-fish diversity is relatively high compared to historical diversity on the same site. The abundance and biomass of the economically important reef fish was much higher in the past than it is now, and spawning aggregations of gag and scamp have been lost or greatly reduced in size. On the west Florida shelf, fishers have concentrated on shelf-edge habitats for over 100 yrs, but fishing intensity increased dramatically in the 1980s. Those reefs are characterized by low abundance of economically important species. The degree and extent of habitat damage there is unknown. We recommend marine fishery reserves to protect habitat and for use in experimentally examining the potential production of unfished communities. Ecosystem-oriented and single-species-oriented fishery management are based on very different goals and considerations. Ecosystem management embraces preservation of biodiversity, maintenance of ecosystem structure and function, and broad-scale climatic considerations, whereas single-species management, in practice, is concerned with optimum exploitation of desirable species. Traditional management plans, in this case, involve social, economic, and biological aspects of fisheries but rarely consider the interspecific or physical processes that impinge upon them. A marked departure from this attitude was reflected in the passage of the Magnuson-Stevens Fishery Management and Conservation Act of 1996, which in effect linked the goals of sustainable fishery production and ecosystem preservation by making habitat a central issue in the management of fisheries. Because the act requires the protection and/or restoration of essential fish habitat, it links preservation of habitat with sustainable production of fishery resources and basically encourages the ecosystem approach to fishery management. Habitat is fundamentally important to fishery production because its loss can profoundly affect productivity (Dayton et al., 1995). Benthic trawling and dredging may be especially damaging (Jones, 1992; Kaiser, 1998; Pilskalin et al., 1998; Watling and Norse, 1998), but other practices, such as removal of apex predators (Goeden, 1982) and other ecologically important species (McClanahan et al., 1999), may have equally severe reper

Abstract: Deep-water Oculina coral reefs, which are similar in structure and development to deep-water Lophelia reefs, stretch over 167 km (90 nmi) at depths of 70–100 m along the eastern Florida shelf of the United States These consist of numerous pinnacles and ridges, 3–35 m in height Coral growth rates average 161 mm yr−1 and biodiversity is very rich Extensive areas of Oculina rubble may be due to human impacts (eg fish trawling and dredging, anchoring, bottom longlines) and natural processes such as bioerosion and episodic die-off Early in the 1970s, the reefs were teeming with fish By the early 1990s, both commercial and recreational fisheries, including scallop, shrimp, grouper, snapper and amberjack, had taken a toll on the reefs and especially on populations of grouper and snapper A 315 km2 (92 nmi2) area was designated the Oculina Habitat of Particular Concern (HAPC) in 1984, prohibiting trawling, dredging, bottom longlines and anchoring, and legislation was enacted in 2000 for expansion of the Oculina HAPC to 1029 km2 (300 nmi2) The United States Coast Guard has been charged with surveillance and enforcement of the ban on bottom fishing and trawling The primary difficulties in protecting these reefs and other deep-water Marine Protected Areas are their remoteness and time required to engage an enforcement vessel Education regarding the nature and importance of these rich resources is important for better self regulation and surveillance by the fishing community Only by bringing deep-water reefs to the public, the fishing community, and enforcement agencies, through video, photos, and education will there be better understanding and acceptance for the need of protection for these unseen resources This paper reviews the current knowledge on the deep-water Oculina reefs, including the biology, geology, human impacts, and history of conservation and management

Abstract: [1] Laser ablation ICP/MS was used to analyze Mg, Sr and U at fine (hundreds of microns) and seasonal spatial scales in the reef coral Porites and the non-photosynthetic “deep-sea” corals Lophelia, Oculina, and Desmophyllum. Tropical corals display strong seasonal correlations between Mg, Sr and U, even when normal cycles are perturbed by unknown factors. An inverse relationship between Mg and U is a universal feature of all the corals, but is much larger in deep corals despite stable environmental conditions. This correlation originates from two aragonitic skeletal types: Mg-rich opaque centers of calcification, and U-rich large translucent crystals. The Mg-rich material probably precipitates rapidly and corresponds to materials strongly deficient in 18O and 13C compared to isotopic equilibrium. Combined, these observations imply that varying proportions of the two skeletal types may account for most of the “temperature” or “climate” signal in tropical corals, as well as anomalous “vital effects”.