Understanding cold-water corals’ health and ecosystems on the Irish margin, NE Atlantic; a critical look into the ecology, geology, hydrodynamic processes and human impacts

• Main Author: Appah, John
• Other Authors: Wheeler, Andrew, Ramsay, Ruth, Lim, Aaron
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University College Cork 2022
• Subjects: Cold-water corals; Porcupine Bank Canyon; Belgica Mound Province; Biodiversity; Marine litter; Health screening; Pathogens; Deep sea; Porcupine Bank; Northeast Atlantic
• Online Access: http://hdl.handle.net/10468/14468

Cold-water corals (CWCs) have come under threat from climate change and anthropogenic activities such as fishing and marine litter pollution despite, being ecological engineers that support high biodiversity, and as a result are protected in Europe under the EU Habitats Directive with some designated as Special Areas of Conservation (SACs). Abiotic (low pH, macro and microplastics) and biotic (pathogens and harmful microbes) factors, due to climate change and human activities, can stress CWCs, disrupting the coral holobiont with dire consequences on the energy allocation processes, coral health and diseases, growth and survival, resilience as well as biodiversity in deep sea corals. CWCs are azooxanthellate, filter feed and exist withing temperature limits of 4-13 °C. Using a habitat mapping approach, coupled with CWC histology and studies of the coral microbiome, this PhD research investigates the CWCs’ ecosystem health and environmental processes that influence biodiversity in the two SACs, upper Porcupine Bank Canyon (uPBC) and the western Belgica Mound Province (wBMP), on the Irish continental margin, northeast Atlantic. Chapter one provides a general introduction to cold-water corals, the objectives of the research and the threats to ocean environmental health and consequent organismal health, while chapter two maps the spatial distribution of CWCs within one of the largest submarine canyons on the Irish margin, the uPBC, highlighting importantly habitat heterogeneity in reef habitats and the hydrographic factors that influence the pattern of CWCs distribution in the canyon. Chapter three mapped the distribution of marine litter in two special areas of conservation (PBC and BMP) on the Irish margin and its impact on CWCs’ distribution as well as to determine if the SACs are serving their purpose and their usefulness against litter entry. In chapter four, the study assessed the distribution and roles of the coral holobiont in the uPBC using molecular techniques whilst chapter five uses a combination of ...