THE EXTENT OF HYDROCARBON CONTAMINATION IN THE MARINE-ENVIRONMENT FROM A RESEARCH STATION IN THE ANTARCTIC

Low level hydrocarbon contamination is measurable in the vicinity of Antarctic stations, N-alkane and polycyclic aromatic hydrocarbon (PAH) concentrations in seawater and sediment at Signy Station, South Orkney Islands indicated contamination was confined to within a few hundred metres of the station. Total n-alkane concentrations in seawater decreased from 7.6 to 2.6 mug l-1 within 500 m of the station. All n-alkane values in seawater were within the limits of variation for oceanic waters proposed by cripps (1992), although the distribution pattern suggested pollution from the station. The total PAH concentration in seawater varied between 110 and 216 ng l-1. These values showed no trend with distance from the station and were all slightly higher than for the open ocean. The n-alkane and PAH concentrations in the surface sediment declined to low levels within 375 m of the station. This indicates that a large proportion of the hydrocarbons entering Factory Cove was deposited from the water column. Sediment n-alkane concentrations were similar at all depths of the cores when collected more than 125 m from the station. PAH levels in the sediment appeared to be due to local input, including a small spill in 1965.