PUB - Publikationen an der Universität Bielefeld

Cold-water coral reefs are highly heterogeneous ecosystems comprising of a range of diverse microhabitats. In a typical European cold-water coral reef various biogenic habitats (live colonies of locally common coral species such as Lophelia pertusa, Paragorgia arborea and Primnoa resedaeformis, dead coral structure, coral rubble) may be surrounded and intermixed with non-biogenic habitats (soft sediment, hardground, gravel/pebbles, steep walls). To date, studies of distribution of sessile fauna across these microhabitats have been more numerous than those investigating mobile fauna distribution. In this study we quantified shrimp densities associated with key CWC habitat categories at the Røst reef, Norway, by analysing image data collected by towed video sled. We also investigated shrimp distribution patterns on the local scale (<40 cm) and how these may vary with habitat. We found shrimp abundances at the Røst reef to be on average an order of magnitude greater in biogenic reef habitats than in non-biogenic habitats. Greatest shrimp densities were observed in association with live Paragorgia arborea habitats (43 shrimp m−2, SD = 35.5), live Primnoa resedaeformis habitats (41.6 shrimp m−2, SD = 26.1) and live Lophelia pertusa habitats (24.4 shrimp m−2, SD = 18.6). In non-biogenic habitats shrimp densities were <2 shrimp m−2. We conclude that CWC reef habitats clearly support greater shrimp densities than the surrounding non-biogenic habitats on the Norwegian margin.