Benthic foraminifera in a deep-sea high-energy environment:the Moira Mounds (Porcupine Seabight, SW of Ireland)

• Published in: Swiss Journal of Geosciences
• Main Authors: Fentimen, Robin, Rüggeberg, Andres, Lim, Aaron, El Kateb, Akram, Foubert, Anneleen, Wheeler, Andrew, J, Spezzaferri, S.
• Other Authors: Department of Geosciences - Earth Sciences Fribourg, Université de Fribourg = University of Fribourg (UNIFR), University College Cork (UCC), Swiss National Science Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: Benthic Foramiifera; Cold-water corals; Carbonate mounds; Bio-sedimentary facies; [SDE.MCG]Environmental Sciences/Global Changes; Porcupine Seabight; North East Atlantic
• Online Access: https://univ-angers.hal.science/hal-04278686; https://univ-angers.hal.science/hal-04278686/document; https://univ-angers.hal.science/hal-04278686/file/s00015-018-0317-4.pdf; https://doi.org/10.1007/s00015-018-0317-4

Cold-water coral ecosystems represent unique and exceptionally diverse environments in the deep-sea. They are welldeveloped along the Irish margin, varying broadly in shape and size. The Moira Mounds, numerous small-sized mounds,are nestled in the Belgica Mound Province (Porcupine Seabight, North-East Atlantic). The investigation of living (RoseBengal stained) and dead benthic foraminiferal assemblages from these mounds allowed to describe their distributionpatterns and to evaluate their response to environmental variability. Quantitative data was statistically treated to definegroups of species/genera associated to specific habitats. The Moira Mounds differ from their larger neighbours by thereduced spatial variability of benthic foraminiferal assemblages, living assemblages only distinguishing coral-rich andcoral-barren areas. The ecological needs of corals are highlighted by the abundance of Alabaminella weddellensis andNonionella iridea, phytodetritus-feeding species in coral supporting sediments. Living foraminifera in sediments from theMoira Mounds concentrate in the upper first centimetre. Infaunal species may be affected by bioturbation and/or reworkingby the strong currents in the area. Dead foraminiferal assemblages from the Moira Mounds resemble those described for thesandwave facies in adjacent giant mounds, suggesting similar processes in facies deposition.