4th International Submarine Canyon Symposium (INCISE2018)

5-7 November 2018, Shenzhen, CHINA

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This is the detail of Temporal variability of cold water coral habitats from the Porcupine Bank Canyon NE Atlantic, using ROV-vibrocoring, CT-scanning and PSA: preliminary results.

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Author
Luke O'Reilly
Co-Author(s)
Aaron Lim, Jürgen Titschack, OJ O'Connor, Kim Harris, John Appah, Andy Wheeler
Abstarct Title
Temporal variability of cold water coral habitats from the Porcupine Bank Canyon NE Atlantic, using ROV-vibrocoring, CT-scanning and PSA: preliminary results.
Abstarct Body
Cold water corals (CWCs) are sessile suspension feeders and occur globally in deep sea settings. They trap current-suspended particles (food, nutrients and sediment) from their environment which becomes deposited in and around the coral framework resulting in the growth of topographic features called CWC mounds. As such, these coral mound features contain a record of paleoenvironmental change through time. Here, we present a project within the Mapping, Modelling and Monitoring Key Processes and Controls on Cold-water Coral Habitats in Submarine Canyons (MMMonkey_Pro; www.marinegeology.ucc.ie) research programme which focuses on the temporal development and paleoenvironmental history of CWC habitats in submarine canyons (reefs, gardens, mounds and coral-derived tallus slopes). This poster presentation shows work completed to date on this project which started in January, 2018. A number of ROV-mounted vibrocore samples have been retrieved from a range of CWC habitat types within the Porcupine Bank Canyon (PBC), NE Atlantic. These cores have been scanned using dual energy computed-tomography (CT) following, and further developing, a novel methodology (see Titschack et al., 2015; 2016). This has created comprehensive imagery of the internal architecture of the CWCs, as representative of reef development stages. The extrapolated data is processed using Amira software and coral core-specific algorithms (Titschack et al. 2015), to reveal variables such as matrix:coral ratio, coral fragmentation, coral fragment orientation and size. The cores have been further logged and subsampled for high-resolution laser granulometry and composition (CaCO3% and Organic%). In early 2019, coral pieces will be subjected to U/Th dating and benthic foraminiferal assemblages will be classified. This unique multidisciplinary ensemble approach will uncover the controls on mound cessation and development related to the dual energy, CT-identified reef development stages. For the first time, we aim to shed light on what controls the formation of different CWC habitats (gardens vs. mounds). Furthermore, analyses of these cores will be an essential component in understanding the key PBC processes and controls on habitat development in submarine canyons.
INCISE Theme
Session 3: Patterns and heterogeneity in submarine canyons
Presentation Type
Poster Presentation
Keywords
cold water corals, CT-scanning, habitat development, submarine canyons

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