Late Holocene benthic formainifera beneath perennial sea ice on an Arctic continental shelf
The Canadian Ice Island Project allows geological, biological and oceanographic studies of regions on the Arctic margin that are beneath the perennial pack ice. High-resolution seismic profiles, grab sampling and bottom photography resulted in the discovery of siliceous sponge reefs on the Axel Heiberg Shelf. Sponge colonies interspersed with mudflats form a variety of biotopes for a rich benthic life. The formainifera assemblage is characterized by large numbers of specimens, high species diversity, predominance of calcareous specimens, and a nearly complete lack of living fauna. The perennial sea ice cover is the main controlling factor of the environment. Low regional runoff and rapid freezing of leads in the ice may explain periodic high bottom salinity, reduced detrital deposition, and low organic matter production. The surface foraminifera assemblage is of a subfossiliferous nature which represents an accumulation of dead tests over approximately 1000 years. Small-scale biotope differences and the resulting patchy distribution of species evolved from the environmental stability of the area. The species composition is unique when compared with other known shallow-water Arctic regions and shows a slight affinity with the Pacific fauna, suggesting a migration through the Bering Strait.
Schroder-Adams, C, Mudie, P.J. (P.J), Cole, F.E. (F.E), & Medioli, F.S. (F.S). (1990). Late Holocene benthic formainifera beneath perennial sea ice on an Arctic continental shelf. Marine Geology, 93(C), 225–242. doi:10.1016/0025-3227(90)90085-X