Spatiotemporal characterization of metals in small craft harbour sediments in Nova Scotia, Canada.


School for Resource and Environmental Studies, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada. Electronic address: [Email]


Spatiotemporal (2001-2017) characterization of sediment metal concentrations were assessed in 31 small craft harbours (SCHs) in Nova Scotia, Canada by analyzing secondary data from government sediment assessment reports. Surficial sediment samples (n = 576) were collected prior to routine maintenance or constriction dredging activities. Sediment metal concentration ranges were 0.5-62 (As), 0.05-3.8 (Cd), 1-305 (Cr), 0.5-220 (Cu), 0.003-1.85 (Hg), 0.73-583 (Pb) and 5-2300 (Zn) mg/kg (dw), respectively. Most sediment metal concentrations (>56% of samples) were below low effect level and >96% were below high effect level sediment quality guidelines, suggesting limited ecological impairment to marine biota. Despite wide temporal coverage (16 years), large variation in sediment concentrations across SCHs were likely due to regular dredging activities preventing long-term accumulation of contaminants. Spatial distribution and enrichment factor results revealed that Canso was most impacted by metals, followed by Clarks Harbour.


Nova Scotia (NS),Sediment metal concentrations,Sediment quality guidelines (SQGs),Small craft harbours (SCHs),