A deep-sea community, including Lophelia pertusa, at unusually shallow depths in the western North Atlantic Ocean off northeastern Florida

Living colonies of the cold-water scleractinian coral Lophelia pertusa and other typically deep-water organisms were discovered in unusually shallow depths (180-250 m) off northeastern Florida. Observations of L. pertusa on rocky substrata and coral-built mounds represent the shallowest records of large colonies of this coral in the western Atlantic Ocean. Bioherms up to 30 m tall, extensive areas of eroded L. pertusa rubble, and a well-developed cold-water community indicated that these sites are long-term features, rather than short-term opportunistic responses to temporary shifts in environmental conditions. Species that are commonly observed on deeper reefs off the southeastern USA were abundant at the shallow sites. The most abundant fishes on reef habitats were Helicolenus dactylopterus, Laemonema barbatulum, Dysommina rugosa, and Anthias spp. In addition to L. pertusa, the most common macroinvertebrates on hard substrata were Eumunida picta, Chaceon fenneri, octocorals, cup corals, and glass sponges. Bottom and near-bottom temperatures (7-10 A degrees C) and nutrient concentrations at the shallow sites were similar to those normally encountered at 500-600 m in this region. The shallow reef sites occur in an area known for frequent Gulf Stream-driven upwelling of deep, nutrient-rich water. However, the upwelling must be persistent or permanent in order to maintain deep-sea communities at such shallow depths. Based on these data, this area is under final review by the US Department of Commerce for inclusion in one of the regional Coral Habitat Areas of Particular Concern.