Presentation Abstract
The temporal and spatial distribution of dissolved and particulate PBDEs seawater concentration has been monitored in the Strait of Georgia (SoG) since 2013. We aim to determine the sources, sinks and biogeochemical cycling of PBDE congeners in the water column in SoG. Particulate PBDEs concentrations show high temporal and spatial variability, indicating that the outfalls from the waste water treatment plants are major point sources. Changes in congener distributions in relation to total particulate PBDE concentrations suggest that the less brominated congeners desorb from sewage particles and add to the dissolved PBDEs pool more rapidly than the more brominated congeners. We also measured very low particulate PBDE concentrations during phytoplankton blooms, which suggest slow kinetics of adsorption or uptake of dissolved PBDEs by phytoplankton. In contrast, the concentrations of dissolved PBDEs in the SoG are more uniform and indicate that the outfalls from waste water treatment plants are not major direct point sources. Other potential sources include atmospheric deposition and desorption from effluent particles after their dispersion. A depth profile of dissolved PBDEs shows higher concentrations of the BDE-47, 99 and 153 at the surface, indicating contributions from the atmosphere or from the Fraser River. However, their highest concentrations were found at, or above, the buoyancy depth of the outfall plume from the Iona Waste Water Treatment Plant. Results obtained to date suggest a differential partitioning of PBDE congeners after their discharge from waste water treatment plants. Less brominated congeners are preferentially desorbed from sewage particles and are preferentially transported towards the surface by the estuarine circulation of the SoG, while the more brominated congeners predominantly remain associated with particles and accumulate on the seafloor. This working hypothesis will be further tested by measuring the kinetics of adsorption/desorption of PBDEs on phytoplankton and sewage particles using C-14 labelled PBDE congeners.
Session Title
Occurrence and impacts of Contaminants of Emerging Concern in the Salish Sea
Keywords
PBDEs, Strait of Georgia, Sinking flux, Adsorption-desorption kinetics, Depth profile
Conference Track
SSE3: Fate, Transport, and Toxicity of Chemicals
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE3-119
Start Date
5-4-2018 3:45 PM
End Date
5-4-2018 4:00 PM
Type of Presentation
Oral
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Biogeochemical cycles--Georgia, Strait of (B.C. and Wash.); Polybrominated diphenyl ethers--Environmental aspects--Georgia, Strait of (B.C. and Wash.); Polybrominated diphenyl ethers--Georgia, Strait of (B.C. and Wash.); Measurement; Water quality biological assessment--Georgia, Strait of (B.C. and Wash.)
Geographic Coverage
Georgia, Strait of (B.C. and Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons, Terrestrial and Aquatic Ecology Commons
Biogeochemical cycling of polybrominated diphenyl ethers (PBDEs) in the Strait of Georgia
The temporal and spatial distribution of dissolved and particulate PBDEs seawater concentration has been monitored in the Strait of Georgia (SoG) since 2013. We aim to determine the sources, sinks and biogeochemical cycling of PBDE congeners in the water column in SoG. Particulate PBDEs concentrations show high temporal and spatial variability, indicating that the outfalls from the waste water treatment plants are major point sources. Changes in congener distributions in relation to total particulate PBDE concentrations suggest that the less brominated congeners desorb from sewage particles and add to the dissolved PBDEs pool more rapidly than the more brominated congeners. We also measured very low particulate PBDE concentrations during phytoplankton blooms, which suggest slow kinetics of adsorption or uptake of dissolved PBDEs by phytoplankton. In contrast, the concentrations of dissolved PBDEs in the SoG are more uniform and indicate that the outfalls from waste water treatment plants are not major direct point sources. Other potential sources include atmospheric deposition and desorption from effluent particles after their dispersion. A depth profile of dissolved PBDEs shows higher concentrations of the BDE-47, 99 and 153 at the surface, indicating contributions from the atmosphere or from the Fraser River. However, their highest concentrations were found at, or above, the buoyancy depth of the outfall plume from the Iona Waste Water Treatment Plant. Results obtained to date suggest a differential partitioning of PBDE congeners after their discharge from waste water treatment plants. Less brominated congeners are preferentially desorbed from sewage particles and are preferentially transported towards the surface by the estuarine circulation of the SoG, while the more brominated congeners predominantly remain associated with particles and accumulate on the seafloor. This working hypothesis will be further tested by measuring the kinetics of adsorption/desorption of PBDEs on phytoplankton and sewage particles using C-14 labelled PBDE congeners.
