Cold-water corals (CWC) are frequently reported from deep sites with locally accelerated currents that enhance seabed food particle supply. Moreover, zooplankton likely account for ecologically important prey items, but their contribution to CWC diet remains unquantified. We investigated the benthic food web structure of the recently discovered Santa Maria di Leuca (SML) CWC province (300 to 1100 m depth) located in the oligotrophic northern Ionian Sea. We analyzed stable isotopes (δ 13 C and δ 15 N) of the main consumers (including ubiquitous CWC species) exhibiting different feeding strategies, zooplankton, suspended particulate organic matter (POM) and sedimented organic matter (SOM). Zooplankton and POM were collected 3 m above the coral colonies in order to assess their relative contributions to CWC diet. The δ 15 N of the scleractinians Desmophyllum dianthus, Madrepora oculata and Lophelia pertusa (8 to 9 ‰) and the gorgonian Paramuricea cf. macrospina (9 to 10 ‰) were consistent with a diet mainly composed of zooplankton (6 to 7 ‰). The antipatharian Leiopathes glaberrima was more 15 N-depleted (7 to 8 ‰) than other cnidarians, suggesting a lower contribution of zooplankton to its diet. Our δ 13 C data clearly indicate that the benthic food web of SML is exclusively fuelled by carbon of phytoplanktonic origin. Nevertheless, consumers feeding at the water-sediment interface were more 13 C-enriched than consumers feeding above the bottom (i.e. living corals and their epifauna). This pattern suggests that carbon is assimilated via 2 trophic pathways: relatively fresh phytoplanktonic production for 13 C-depleted consumers and more decayed organic matter for 13 C-enriched consumers. When the δ 13 C values of consumers were corrected for the influence of lipids (which are significantly 13 C-depleted relative to other tissue components), our conclusions remained unchanged, except in the case of L. glaberrima which could assimilate a mixture of zooplankton and resuspended decayed organic matter.

Studies on the distribution of scleractinian corals in the Bay of Biscay were relatively numerous during the nineteenth and the Wrst half of the twentieth century. Yet, recent reports are scattered, sometimes unpublished, and therefore knowledge about the current coral occurrence in the area is limited. This study aims at compiling the available historical and more recently collected information on the occurrence of scleractinian corals in the Bay of Biscay. Data from two recent cruises are included and compared with previous explored coral sites from as early as 1830 up to 1995. A database of 347 records including 34 described species of scleractinians highlights that the slope of the Bay of Biscay is an important habitat for scleractinians. This could be expected due to the high topographic relief providing the necessary hard substrate and accelerated bottom current Xow that corals require. Further exploration of the occurrence and ecology of corals in the area is recommended to support the conservation of cold-water coral reefs along the European margin.

The West African continental slope is an important theatre for geological survey prospecting and drilling for hydrocarbons but little is known about local deep-sea biological communities at these depths. While shallow-water reefs are common and well-known features in the tropics, only few records of deep-water corals exist at low latitudes, and most of them have been reported by historical oceanographic cruises undertaking circum-navigations of the world. This study, based on a multidisciplinary approach, presents a description of newly discovered deep-water coral reef communities along the Angola margin. Data from ROV, multibeam bathymetry, side-scan sonar and seismics from a deep-towed acoustic system (SAR) were used to describe the morphology of the coral mounds and their relationship with the local geological setting. The reef-building scleractinian coral Lophelia pertusa has colonised carbonate mounds that reach heights of ca. 30 m and follow an orientation that is correlated with salt tectonic processes. Recent erosion is suggested as a process that influences the shape of the mounds. Sixteen fish taxa were identified during the ROV video surveys, with some of them likely to have a strong affinity with dense-living corals. The species observed belong to families commonly associated with deep-water corals (i.e. Sebastidae, Berycidae, Lophiidae and Chaunacidae), except an abundant species belonging to the family Zoarcidae, rarely observed in this type of environment. Lucinidae shells were found around mounds. As this bivalve family is indicative of reduced sediment and generally associated with cold-seep environments, this finding could revive the debate over the relationship between the distribution of cold-water coral habitat and gas seeps. However, there is no present-day nutritional relationship between living coral and chemosynthetic-derived biomass. The possible role of fluid expulsion in carbonate precipitation acting as the first step for coral colonisation is nevertheless discussed.

28We report the northernmost and deepest known occurrence of deep-water pycnodontine 29 oysters, based on two surveys along the French Atlantic continental margin to the La 30Chapelle continental slope (2006)

Although there are no previous descriptions of the habits of chirostylids in the North Atlantic, it is likely that species in the generaUroptychus,EumunidaandGastroptychushave close ecological ties with deep-sea corals since they have all been recorded in trawl samples containing corals from >200 m depth. We analysedin situdistribution ofGastroptychus formosusand potential hosts using a ROV at a range of north-eastern Atlantic sites and found that this species forms a close association with deep-sea corals that resembles the chirostylid–anthozoan associations reported in shallow Indo-Pacific waters. We update the known distribution forG. formosus, confirming that it is an amphiatlantic species that occurs along the Mid-Atlantic Ridge at least as far south as the Azores and along continental margins from the Canary Islands to Scotland at depths of 600–1700 m. The adults have very specific habitat preferences, being only found on gorgonian and antipatharian corals with a strong preference forLeiopathessp. as a host. This highly restricted habitat preference is likely to render chirostylids vulnerable to the impacts of demersal fishing both directly, as by-catch, and indirectly through habitat loss.