Characterization and evaluation of potential contaminants of concern in small craft harbour sediments in Nova Scotia

Abstract

Small craft harbours (SCHs) are vital for the fishing industry, but can be impacted by contamination in marine sediments. This study characterized the distribution of petroleum hydrocarbons (PHCs) and polychlorinated biphenyls (PCBs) in 31 SCHs sediments in Nova Scotia between 2000 and 2017. Federal and regional sediment quality guidelines were used to determine exceedances. An ecological risk evaluation for PHCs, PCBs and previously characterized contaminants was also conducted using two different approaches. While results showed exceedances for heavy PHCs, only 7% of samples exceeded maximum recommended screening level, showing low risk. PCBs did not pose high risk to biota, with only six samples exceeding the higher effect level. Most SCHs showed low ecological risk, with two SCHs presenting high risk. Monitoring is recommended for high risk SCHs to determine extent of contamination. Integrated results inform harbour managers about the historical state of SCHs, so future risk-management options can be developed.