SPATIO-TEMPORAL POLYCYCLIC AROMATIC HYDROCARBON (PAH) CHARACTERIZATION AND ASSESSMENT IN SMALL CRAFT HARBOUR SEDIMENTS IN NOVA SCOTIA

Abstract

Small craft harbour (SCH) environments play an important role in the fisheries industry of Nova Scotia (NS). SCHs support various fisheries and are federally managed by Fisheries and Oceans Canada (Small Craft Harbours), in support of this sector. SCHs, similar to other coastal environments, are prone to point and non-point sources of contamination which can pose a risk to biota and human health. This study examines one common class of contaminants which find their way into harbour sediments: polycyclic aromatic hydrocarbons (PAHs). In a multi-faceted approach, PAHs were evaluated across 31 SCHs in NS for the temporal period of 2001-2017, with improved characterization and source apportionment of PAHs as two key research objectives. Results indicate that the majority of SCHs across NS demonstrate PAH concentrations best characterized as low risk to biota (based on empirical sediment quality guidelines) and are dominated by compounds which have low mobility in the water column. Multiple lines of evidence indicate that PAHs in NS SCHs are mainly produced by combustion processes, including coal combustion, biomass combustion, and vehicular emissions. Furthermore, the implemented research approaches and recommendations of this study demonstrate usefulness and support for federal SCH management across Canada.