Sedimentary biomarkers along a contamination gradient in a human-impacted sub-estuary in Southern Brazil: a multi-parameter approach based on spatial and seasonal variability.

The composition and seasonal variations of sedimentary organic matter were investigated along the Cotinga sub-estuary, located in Paranaguá Bay, a large South American estuary where urban activities and the primary Brazilian grain shipping port are sources of pollution. Steroids and hydrocarbons were analyzed in surface sediments collected during the austral winter (2008) and summer (2009) in three distinct sectors, along this sub-estuary in a presumed gradient of fecal contamination. Concentrations ranged from 0.28 to 7.33 μgg (-1) (in dry sample weight thereafter),