Hydrocarbons in Coastal Sediments of Patagonia, Argentina: Levels and Probable Sources

Intertidal superficial sediment from the Patagonian coastal zone were analysed to determine the concentration and probable source of aromatic and aliphatic hydrocarbons. Concentrations of aromatic and aliphatic hydrocarbons ranged from non-detected to 737.6 μg/g and non-detected to 1304.7 μg/g of dry sediment, respectively. High concentrations were observed in San Jorge Gulf, where the main economic activities are based on crude oil production. The highest aromatic and aliphatic hydrocarbon concentrations were present at Faro Aristizábal, 200 km away from oil charging areas. As suspected, hydrocarbon levels in harbour areas were generally more important than at nearby zones. Lower or non-detected hydrocarbon levels were recorded at locations with low or non-anthropogenic activity. Alkane distribution indices and hydrocarbon distribution patterns were used to identify natural and anthropogenic inputs. The results showed recent crude oil inputs and contribution from remaining weathered residues at various locations, whereas biogenic compounds or biogenic in combination with anthropogenic hydrocarbons predominated in others