Presentation Abstract

We examine the influence of sediment factors on uptake of PBDEs into marine deposit and filter feeders, and transfer to higher trophic levels. Sediment PBDEs increase with %toc, AVS, organic flux, and fines. As a result, coarser, less organic sediments in JdF have lower [PBDEs] than the southern SoG. Sediment feeder [PBDE] variance was best explained by AVS>[PBDEs]>%TOC>OC flux. Therefore, increasing organic input and burn-down, and sediment PBDEs enhance tissue PBDEs. Dry weight PBDE accumulation (tissue/sediment) in sediment feeders decreased with increasing sediment PBDEs, resulting in tissue dilution at sediment concentrations >10,000pg/g in urban harbours. PBDE accumulation decreased with increasing fines. As a result, accumulation was higher in JdF than SoG. These patterns imply low bioavailability at high sediment PBDEs. Dry weight PBDEs increased ~107x from background benthos to predators, crabs and seal blubber, whereas lipid weight differences were 1. Thus bio-accumulation trends require understanding of food resources in higher trophic fauna. The greatest change in congenor composition occurs at sediment uptake. Dominant nona/deca- BDEs in sediments decline concurrent with increasing tetra-hexa BDEs. Sediment feeders near outfalls and in background locations had similar proportions of congenors. Harbour feeders had a composition similar to sediments. Along with the noted bio-dilution, this suggests that uptake of PBDEs is so rapid at high sediment levels that most passes un-modifed through guts. BDE-209 varies throughout the food chain, reflecting shifting dependence on sediment versus pelagic food resources. In higher trophic level fauna, debromination of penta/hexa to tetra BDEs is much slower than initial debromination of deca/nona-BDEs. Tetra-BDEs appear to be a metabolic "dead-end".

Session Title

Contaminants in Marine Mammals of the Salish Sea and Their Food Web

Keywords

PBDEs, Trophic uptake, Benthos

Conference Track

SSE3: Fate, Transport, and Toxicity of Chemicals

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE3-595

Start Date

4-4-2018 1:30 PM

End Date

4-4-2018 1:45 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

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Apr 4th, 1:30 PM Apr 4th, 1:45 PM

Uptake and trophic changes of PBDEs in the benthic marine food chain

We examine the influence of sediment factors on uptake of PBDEs into marine deposit and filter feeders, and transfer to higher trophic levels. Sediment PBDEs increase with %toc, AVS, organic flux, and fines. As a result, coarser, less organic sediments in JdF have lower [PBDEs] than the southern SoG. Sediment feeder [PBDE] variance was best explained by AVS>[PBDEs]>%TOC>OC flux. Therefore, increasing organic input and burn-down, and sediment PBDEs enhance tissue PBDEs. Dry weight PBDE accumulation (tissue/sediment) in sediment feeders decreased with increasing sediment PBDEs, resulting in tissue dilution at sediment concentrations >10,000pg/g in urban harbours. PBDE accumulation decreased with increasing fines. As a result, accumulation was higher in JdF than SoG. These patterns imply low bioavailability at high sediment PBDEs. Dry weight PBDEs increased ~107x from background benthos to predators, crabs and seal blubber, whereas lipid weight differences were 1. Thus bio-accumulation trends require understanding of food resources in higher trophic fauna. The greatest change in congenor composition occurs at sediment uptake. Dominant nona/deca- BDEs in sediments decline concurrent with increasing tetra-hexa BDEs. Sediment feeders near outfalls and in background locations had similar proportions of congenors. Harbour feeders had a composition similar to sediments. Along with the noted bio-dilution, this suggests that uptake of PBDEs is so rapid at high sediment levels that most passes un-modifed through guts. BDE-209 varies throughout the food chain, reflecting shifting dependence on sediment versus pelagic food resources. In higher trophic level fauna, debromination of penta/hexa to tetra BDEs is much slower than initial debromination of deca/nona-BDEs. Tetra-BDEs appear to be a metabolic "dead-end".