4th International Submarine Canyon Symposium (INCISE2018)

5-7 November 2018, Shenzhen, CHINA

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This is the detail of Characterisation of Key Processes on Cold Water Coral Distribution in the Porcupine Bank Canyon, NE Atlantic

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Author
John Appah K.M
Co-Author(s)
Luke O’Reilly, Kimberley Harris, Aaron Lim, Ruth Ramsay, Andy Wheeler
Abstarct Title
Characterisation of Key Processes on Cold Water Coral Distribution in the Porcupine Bank Canyon, NE Atlantic
Abstarct Body
Submarine canyons serve as channels where sediments, nutrients and organic matter from continental shelves are transported into the abyssal zone. The processes that occur within the canyon give rise to habitat heterogeneity which, in turn, support high biodiversity. The Porcupine Bank Canyon (PBC), located on the southwestern coast of Ireland, is cut off from direct river and shelf sediment inputs, making it an ideal model to investigate and understand the key control processes of the cold water coral habitats predominantly Lophelia pertusa and Madrepora oculata, through time and in space. A remotely operated vehicle (ROV) was used to collect HD video data of the seafloor to assess the different macrohabitats and megabenthic community structure existing within the canyon as well as anthropogenic fingerprints. Oceanographic variability were measured with Conductivity-Temperature-Depth (CTD) casts while particulate organic matter (POM) concentrations were analysed at different depths at different stations in the vicinity of the CWC. Our preliminary results show that the amount of POM did not vary with depth, suggesting that food availability may not be the major process affecting the distribution of the corals. Also, the video data revealed active, densely growing Lophelia pertusa corals at 600 - 800 m and small, sparsely growing corals at deeper parts of the canyon, and the presence of litter and fishing lines. CTD casts showed that corals occurring between depths of 600 - 1000 m were bathed with Eastern North Atlantic Water (ENAW). In addition, CTD casts showed a narrow variation in temperature, salinity and oxygen from 600 - 1200 m. Overall, habitat variability, carbon flux and oceanographic processes likely control benthic species distribution in the canyon.
INCISE Theme
Session 3: Patterns and heterogeneity in submarine canyons
Presentation Type
Poster Presentation
Keywords
cold water coral, canyons, habitat heterogeneity, biodiversity

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