COMPARISON OF DIATOM PRESERVATION BETWEEN OXIC AND ANOXIC BASINS IN ELLIS FJORD, ANTARCTICA

Abstract

Sedimentary diatom assemblages from adjacent sub-basins in Ellis Fjord reflect the differing degree of oxygenation in each of their bottom waters. The absence of a benthic fauna and a lower pH in the anoxic sub-basin allows the preservation of the smaller, more fragile diatoms. By contrast, the presence of an active benthos and a higher pH in the well-oxygenated sub-basin results in preservation of only the more robust species. Approximately 50% of diatom cells sedimenting from the surface waters of the oxygenated sub-basin of Ellis Fjord are removed prior to incorporation into the sediments.