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

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.

Similarity analyses in restoration ecology and how to improve their utility

“…For instance, investigations into intertidal marine invertebrates that reproduce via broadcast spawning may fail to identify habitat patches experiencing hypoxic stress if only community similarity is investigated, and sediment biogeochemistry variables are neglected. Source communities can support similar communities on disturbed patches, obscuring identification of disturbed patches through assessments of community composition (Gerwing et al 2017 a ; Gerwing et al 2018 a ; Gerwing et al 2018 b ; Campbell et al 2019; Sizmur et al 2019). Furthermore, an exclusive focus on community similarity may also fail to identify reference sites that are disturbed, but superficially similar to other, true reference sites.…”

Immediate response of fish communities and water chemistry to causeway breaching and bridge installation in the Kaouk River estuary, British Columbia, Canada

“…These coastal habitats offer critical environmental services such as flood reduction and water filtration (Zedler ; Elliott et al ; Elliott & Whitfield ), and are important nursery grounds for Pacific salmon (Simenstad et al ; Moore et al ; Kennedy et al ). Unfortunately, human populations in coastal areas are three times that of the global average, resulting in estuaries becoming heavily impacted by human activities (Small & Nicholls ; Cox et al ; Sizmur et al ). These impacts have resulted in species loss, disruption of community dynamics, and habitat fragmentation (Locke et al ; Crain et al ; Ban et al ).…”

“…These impacts have resulted in species loss, disruption of community dynamics, and habitat fragmentation (Locke et al ; Crain et al ; Ban et al ). Further, as they grant access to inland habitats, estuaries are often hubs of industrial activities, such as logging (Simenstad et al ; Musick et al ), metal smelting, and pulp and paper production (Yunker et al ; Gerwing et al ; Sizmur et al ). Another common form of human alteration in estuaries is the construction of dikes and causeways built to enhance transportation through estuaries, as well as convert wetlands into habitat suitable for development or farming (Eertman et al ; Hood ; Gerwing et al ).…”

Geospatial analysis of the patterns of chemical exposures among biota in the Canadian Oil Sands Region

“…Further, non-essential metals (i.e., mercury, cadmium, lead) are not required for homeostasis and can be toxic even at low doses [22]. Two previous studies have assessed complex metal exposures in benthic organisms and small mammals using principal components analysis [23,24]. However, wildlife contaminants monitoring data collected from the Canadian Oil Sands have yet to be integrated for exposure assessment.…”