Deep-water coral reefs from the Uruguayan outer shelf and slope

We report the finding of monospecific scleractinian (i.e. Lophelia pertusa) reefs from the Uruguayan outer shelf and slope during an exploratory joint research cruise onboard the R/V 'Miguel Oliver' during January-February 2010. Acoustic mapping of the seafloor allowed the detailed analysis of 8,944 km(2), where some 17 structures identified as mounds were detected. Isolated cusps or groups of small mounds were the two main morphologies observed. Mound summit depths ranged from 167 to 326 m. The average height of the mounds was 35 m, reaching a maximum of 67 m. In all sampled mounds, the presence of live coral and/or coral rubble was detected, while absent from surrounding soft sediment bottoms. Some mounds were associated with fluid seepages. This is the first report of deep-sea coral reefs on the Uruguayan continental shelf and slope, and represents the southernmost Western Atlantic shelf and slope record of L. pertusa to date