Benthic foraminifera in a deep-sea high-energy environment: the Moira Mounds (Porcupine Seabight, SW of Ireland)
Résumé
Cold-water coral ecosystems represent unique and exceptionally diverse environments in the deep-sea. They are well
developed 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 (Rose
Bengal stained) and dead benthic foraminiferal assemblages from these mounds allowed to describe their distribution
patterns and to evaluate their response to environmental variability. Quantitative data was statistically treated to define
groups of species/genera associated to specific habitats. The Moira Mounds differ from their larger neighbours by the
reduced spatial variability of benthic foraminiferal assemblages, living assemblages only distinguishing coral-rich and
coral-barren areas. The ecological needs of corals are highlighted by the abundance of Alabaminella weddellensis and
Nonionella iridea, phytodetritus-feeding species in coral supporting sediments. Living foraminifera in sediments from the
Moira Mounds concentrate in the upper first centimetre. Infaunal species may be affected by bioturbation and/or reworking
by the strong currents in the area. Dead foraminiferal assemblages from the Moira Mounds resemble those described for the
sandwave facies in adjacent giant mounds, suggesting similar processes in facies deposition.
Origine : Publication financée par une institution
Licence : CC BY - Paternité
Licence : CC BY - Paternité