Relationships between Potentially Toxic Elements in intertidal sediments and their bioaccumulation by benthic invertebrates.

Tom Sizmur,Nelson J O’Driscoll,Megan Jones,Lily Campbell,Karina Dracott,Travis Gerwing,Judi Hewitt

doi:10.1371/journal.pone.0216767

Abstract

The bioaccumulation of Potentially Toxic Elements (PTEs) by benthic invertebrates in estuarine sediments is poorly understood. We sampled and analysed PTEs in sediments and benthic invertebrates from five sites in the Skeena Estuary (British Columbia, Canada), including sites adjacent to an abandoned cannery and a decommissioned papermill. Our aim was to elucidate baseline levels of PTE concentrations at sites that may be recovering from disturbance associated with prior industrial development and identify organisms that could be used to biomonitor the impact of future industrial developments. There was no indication that sediments of the salmon cannery were 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 mostly recovered from prior industrial development associated with discharge of papermill sludge. Overall, we did not observe any relationship between PTE concentrations in the sediment and PTE concentrations in invertebrate tissues. However, we did observe a negative relationship between sediment pH and the Biota-Sediment Accumulation Factor (BSAF) of most PTEs for Oregon pill bugs (Gnorimosphaeroma oregonensis). G. oregonensis, observed at all sites, feeds on the fibers associated with the papermill discharge. Thus, G. oregonensis is a useful biomonitors for quantifying the impact of the decommissioned papermill, and are candidate biomonitors for assessing the impact of similar industrial development projects on intertidal ecosystems.

Highlights

Intertidal estuarine habitat is both ecologically and economically important, providing nursery habitats to several species, such as juvenile pacific salmon, that support important commercial fisheries [1]
There was no significant (p > 0.05) difference in the median sediment particle diameter between Inverness Passage and Cassiar Cannery, or between Wolfe Cove and Papermill Bay (Fig 2 and S3 Table). This observation supports our assumption that the sediment deposited in the sites potentially contaminated by industrial development (Cassiar Cannery and Papermill Bay) and their respective proximal reference sites (Inverness Passage and Wolfe Cove) have the same geogenic origin and are subject to a similar depositional environment
Because Tyee Banks is much further from potential pollution sources, the site can be used to determine whether proximal reference (Inverness Passage and Wolfe Cove) sites are contaminated with Potentially Toxic Elements (PTEs) from the adjacent historic industrial developments

Summary

Introduction

Intertidal estuarine habitat is both ecologically and economically important, providing nursery habitats to several species, such as juvenile pacific salmon, that support important commercial fisheries [1]. Toxic Elements in intertidal sediments and their bioaccumulation by benthic invertebrates study design, data collection and analysis, decision to publish, or preparation of the manuscript

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Methods

Results

Conclusion