Survey of intertidal ecosystem reveals a legacy of potentially toxic elements from industrial activity in the Skeena Estuary, British Columbia, Canada

Relationships between concentrations of Potentially Toxic Elements (PTEs) in estuarine sediments and their impact benthic invertebrate communities are poorly understood. We sampled and analysed PTEs in sediments and benthic invertebrates from five sites surrounding the Skeena Estuary, including sites adjacent to an abandoned cannery and a decommissioned papermill. There was no indication that sediments of the salmon cannery are polluted, but acidic sediments adjacent to the papermill contained elevated concentrations of Cd, Cr, Hg and Pb. Benthic invertebrate community assemblages confirm that sediments have recovered from prior disturbances associated with discharge of papermill sludge. Oregon pill bugs ( Gnorimosphaeroma oregonensis ), observed at all five sites, feed on the fibers associated with the papermill discharge. Thus, G. oregonensis are useful biomonitors for quantifying the impact of the decommissioned papermill, and similar industrial development projects, on intertidal ecosystems along the north coast of British Columbia, Canada.