Analysis of foraminiferal populations in sediment samples from McMurdo Sound in relation to sediment type, ecological factors and bathymetry

Sea floor sediments of McMurdo Sound were sampled to obtain material suitable for detailed analysis of foraminiferal populations and their relationships to sediment type and ecological factors. Foraminifera are sensitive to a wide range of pollutants and baseline information on their present distribution may well be useful to help assess environmental impact in the future. Material was obtained over several seasons, using the sea ice as a platform but also from a boat, from New Harbour, near the McMurdo Station desalination plant discharge point, off Cape Royds, across McMurdo Sound from Cape Evans to the Strand Moraines, Cape Roberts, across Granite Harbour from Cape Roberts to Cape Archer and in front of the Mackay and New Glacier in Granite Harbour. Material was obtained from core and grab samples retrieved by dropping equipment through an access hole in the sea ice and from research based vessel (Cruise IV of USCGS GLACIER, Benjamin Bowring). Depths ranged from 8 to 850 m. Grain size analysis was completed in all cores to determine marine sedimentation in the area of sampling. Bathymetry beyond the coastal fringe was obtained from continuous depth recorder records off cruises and personnel since 1972 and was plotted for comparison with samples (approx 500 points). Current velocity and tide was measured over a 2 day period in 167m of water 0.6km off the edge of the Strand Moraines.