MICROHABITAT PREFERENCES OF BENTHIC FORAMINIFERA FROM AUSTRALIA’S MURRAY SUBMARINE CANYON GROUP

Microhabitat preferences of living (rose Bengal stained) benthic foraminifera were evaluated in four multicores taken from a depth transect (350-2500m) within the Murray Submarine Canyon System located 60 km south of Kangaroo Island, Australia. Foraminiferal assemblage (>150 µm) abundances are relatively high, and decrease with water depth. Substantial infaunal populations are present in all four cores, with maximum faunal densities occurring deeper than 1 cm sediment depth. Deep infaunal species, Chilostomella oolina and Globobulimina spp., display characteristic subsurface distribution patterns. Bolivinita quadrilatera appears to prefer a shallow infaunal habitat. While most paleoceanographically-important taxa maintain vertical distribution profiles similar to those previously observed in other regions, some taxa occur deeper within the sediments. The occurrence of appreciable infaunal abundances may result from subsurface food availability caused by turbidite sedimentation.