Sedimentary hydrocarbons and sterols in a South Atlantic estuarine/shallow continental shelf transitional environment under oil terminal and grain port influences

- Hydrocarbon and sterol distributions clearly distinguish marine from terrestrial organic matter inputs.
- Principal component analysis explained the spatial distinction of the sampling sites and biomarkers.
- Organic markers suggest that the study region should be considered a pristine environment.

Sterols and hydrocarbons were determined in the surface sediments from the transitional environment between Paranaguá Bay and the shallow continental shelf in the South Atlantic to assess the sources of organic matter (OM) and the contamination status of an area exposed to multiple anthropogenic inputs. Total aliphatic hydrocarbon concentrations were less than 10 μg g−1, which is typical of unpolluted sediments, and related to recent inputs from higher terrestrial plants. Total polycyclic aromatic hydrocarbon ranged from