Event Title

Comparisons of toxic chemicals in nearshore sediment and caged mussels in Puget Sound, Washington: implications for monitoring studies

Presentation Abstract

To establish baseline contaminant concentrations in Puget Sound mussel tissue and nearshore sediment, the Stormwater Action Monitoring (SAM) program deployed caged mussels in over 70 locations in winter 2015-16 and collected nearshore sediment from many of those same locations during summer 2016. To link the two data sets and provide new information about the relation between contaminants in mussel tissue and co-located sediment, the U.S. Geological Survey’s Coastal Habitats in Puget Sound Project collected nearshore sediment at select mussel biomonitoring sites during cage retrieval in February 2016. Sites with fine-grained sediment were targeted, and samples were sieved to particle sizes less than 0.063 millimeters (mm) for analysis of organic carbon, metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyl (PCB) congeners. Concentrations of metals including arsenic, cadmium, copper, mercury, and zinc were less variable in mussel tissue than in co-located fine nearshore sediment, suggesting bioregulation of metals by these bivalves. Concentrations of PAHs and PCBs in tissue and sediment were variable between sites, with the highest concentrations in urban embayments, consistent with bioaccumulation of organic compounds in bivalves. Most contaminant concentrations in summer sediment samples were lower than those in winter sediment samples, likely due to the larger grain size (summer samples sieved to <2 mm vs. <0.063 mm for winter samples) and further offshore location (80-320 meters further offshore and 2 meters deeper than the corresponding winter sample). To address this discrepancy, we analyzed both size fractions in select sediment samples. Metals and PCBs preferentially sorb to fine sediment, while partition of PAHs appears more variable. These differences in toxic chemical partitioning among sediment size fractions, low and high energy sites, seasons, and proximal versus distal collection sites should be considered during program design and interpretation for chemical concentrations in Puget Sound sediment and biological matrixes.

Session Title

Monitoring Stormwater Impacts on Contaminants in Receiving Waters

Conference Track

SSE3: Fate, Transport, and Toxicity of Chemicals

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE3-220

Start Date

6-4-2018 2:30 PM

End Date

6-4-2018 2:45 PM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (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

This document is currently not available here.

Share

COinS
 
Apr 6th, 2:30 PM Apr 6th, 2:45 PM

Comparisons of toxic chemicals in nearshore sediment and caged mussels in Puget Sound, Washington: implications for monitoring studies

To establish baseline contaminant concentrations in Puget Sound mussel tissue and nearshore sediment, the Stormwater Action Monitoring (SAM) program deployed caged mussels in over 70 locations in winter 2015-16 and collected nearshore sediment from many of those same locations during summer 2016. To link the two data sets and provide new information about the relation between contaminants in mussel tissue and co-located sediment, the U.S. Geological Survey’s Coastal Habitats in Puget Sound Project collected nearshore sediment at select mussel biomonitoring sites during cage retrieval in February 2016. Sites with fine-grained sediment were targeted, and samples were sieved to particle sizes less than 0.063 millimeters (mm) for analysis of organic carbon, metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyl (PCB) congeners. Concentrations of metals including arsenic, cadmium, copper, mercury, and zinc were less variable in mussel tissue than in co-located fine nearshore sediment, suggesting bioregulation of metals by these bivalves. Concentrations of PAHs and PCBs in tissue and sediment were variable between sites, with the highest concentrations in urban embayments, consistent with bioaccumulation of organic compounds in bivalves. Most contaminant concentrations in summer sediment samples were lower than those in winter sediment samples, likely due to the larger grain size (summer samples sieved to <2 mm vs.><0.063 mm for winter samples) and further offshore location (80-320 meters further offshore and 2 meters deeper than the corresponding winter sample). To address this discrepancy, we analyzed both size fractions in select sediment samples. Metals and PCBs preferentially sorb to fine sediment, while partition of PAHs appears more variable. These differences in toxic chemical partitioning among sediment size fractions, low and high energy sites, seasons, and proximal versus distal collection sites should be considered during program design and interpretation for chemical concentrations in Puget Sound sediment and biological matrixes.