Presentation Abstract
The temporal and spatial distribution of dissolved PBDE concentration in the Strait of Georgia (SoG) is combined with concentrations predicted from a time-dependent box model of the Salish Sea to investigate the sources, sinks, dispersion and cycling of PBDE congeners. Prominent sub-surface concentration maxima (up to ca. 400 pg/L for total PBDE) occasionally measured in the southern SoG point to the Iona Island Waste Water Treatment Plant diffusers, discharging primary-treated effluent at 72 - 106 m depth, as an important proximal point source of dissolved PBDE. The decreasing depth of concentration maximum with increasing congener bromination suggests that dissolved PBDEs are desorbed from sewage particles, at rates decreasing with their level of bromination, as the effluent plume rises to its depth of neutral buoyancy (ca. 50 m). The much lower dissolved PBDE concentrations measured in the northern SoG, Haro Strait and Juan de Fuca Strait reflects dilution of the effluent plume by mixing and removal of dissolved PBDE by adsorption on settling marine particles. The large temporal variability of dissolved PBDE concentration in the southern SoG is related to hydrography and the time of residence of the sampled water in the SoG. The lower concentrations of dissolved PBDE predicted by the Salish Sea box model by adding PBDE in the SoG at a rate equivalent to effluent discharge from waste water treatment plants measured in 2003 indicate a higher effluent PBDE concentration in recent years or another dissolved PBDE subsurface source yet to be identified.
Session Title
Session 1.2B: Contaminants in the Salish Sea: Sources, Movement, and Fate
Conference Track
Contaminants, Plastics, Microplastics, Toxicology & Stormwater
Conference Name
Salish Sea Ecosystem Conference (2020 : Online)
Document Type
Event
SSEC Identifier
2020_abstractID_4012
Start Date
21-4-2020 12:30 PM
End Date
21-4-2020 2:00 PM
Genre/Form
conference proceedings; presentations (communicative events)
Subjects – Topical (LCSH)
Polybrominated diphenyl ethers--Salish Sea (B.C. and Wash.); Water--Pollution--Research--Salish Sea (B.C. and Wash.)
Geographic Coverage
Salish Sea (B.C. and Wash.)
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
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
Sources, sinks, dispersion and cycling of dissolved polybrominated diphenyl ethers (PBDEs) discharged in the Strait of Georgia
The temporal and spatial distribution of dissolved PBDE concentration in the Strait of Georgia (SoG) is combined with concentrations predicted from a time-dependent box model of the Salish Sea to investigate the sources, sinks, dispersion and cycling of PBDE congeners. Prominent sub-surface concentration maxima (up to ca. 400 pg/L for total PBDE) occasionally measured in the southern SoG point to the Iona Island Waste Water Treatment Plant diffusers, discharging primary-treated effluent at 72 - 106 m depth, as an important proximal point source of dissolved PBDE. The decreasing depth of concentration maximum with increasing congener bromination suggests that dissolved PBDEs are desorbed from sewage particles, at rates decreasing with their level of bromination, as the effluent plume rises to its depth of neutral buoyancy (ca. 50 m). The much lower dissolved PBDE concentrations measured in the northern SoG, Haro Strait and Juan de Fuca Strait reflects dilution of the effluent plume by mixing and removal of dissolved PBDE by adsorption on settling marine particles. The large temporal variability of dissolved PBDE concentration in the southern SoG is related to hydrography and the time of residence of the sampled water in the SoG. The lower concentrations of dissolved PBDE predicted by the Salish Sea box model by adding PBDE in the SoG at a rate equivalent to effluent discharge from waste water treatment plants measured in 2003 indicate a higher effluent PBDE concentration in recent years or another dissolved PBDE subsurface source yet to be identified.
