Presentation Title

Toxicity in Sinclair and Dyes Inlet sediments as indicated by benthic foraminifera.

Session Title

Session S-03A: Changes in Salish Sea Water Quality

Conference Track

Marine Water Quality

Conference Name

Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)

Contributing Repository

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

Presenter/Author Information

Ruth Martin, University of WashingtonFollow

Start Date

1-5-2014 5:00 PM

End Date

1-5-2014 6:30 PM

Abstract

Sinclair and Dyes Inlets surround the city of Bremerton, Washington, and contain some of the most contaminated sediments in Puget Sound. The city is home to the Puget Sound Naval Shipyard, a designated Superfund site; sediments there are contaminated with PCBs, PAHs and toxic metals. Ostrich Bay, an embayment off Dyes Inlet, was the site of a Naval Ordnance facility where munitions were manufactured and destroyed, with by-products washed and dumped into the bay. In addition to industrial pollutants, agricultural and recreational uses of the surrounding land introduce their own contaminants, particularly fecal coliform, phosphorus and metals. This study utilized foraminifera to assess the condition of the benthic ecosystem. Thirty-five sediment samples collected by the Washington Department of Ecology (WADOE) were analyzed for their foraminiferal assemblages which were then correlated with data on sediment quality and chemistry. Of those samples, 20% were barren of foraminifera, and in the rest, species richness was relatively low, averaging four species per sample. The Shannon diversity index also indicated low diversity, averaging 0.99. Many samples contained large percentages of calcareous foraminifera that showed signs of dissolution. Samples that were barren of foraminifera and those that showed pronounced dissolution displayed high levels of Total Organic Carbon (TOC); the decomposition of organic material may well have resulted in anoxic conditions and low pH. The former may explain the lack of foraminifera in samples, and the latter may be responsible for the dissolution of foraminiferal tests. Comparison of foraminiferal diversity and toxic metal concentrations demonstrated a negative correlation between the two. Several samples in both inlets contain numerous euhedral crystals of gypsum. These samples displayed high TOC and were either barren of foraminifera or showed very low diversity. Analysis of sulfur isotopes indicate the gypsum is the result of sulfate reduction, either from decomposition of organic matter or from industrial processes. Thus, foraminiferal assemblages in marine waters surrounding Bremerton are responding markedly to conditions in the sediments, establishing the efficacy of using foraminifera as a tool for monitoring benthic ecosystems in Puget Sound.

Rights

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Language

English

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May 1st, 5:00 PM May 1st, 6:30 PM

Toxicity in Sinclair and Dyes Inlet sediments as indicated by benthic foraminifera.

Room 6C

Sinclair and Dyes Inlets surround the city of Bremerton, Washington, and contain some of the most contaminated sediments in Puget Sound. The city is home to the Puget Sound Naval Shipyard, a designated Superfund site; sediments there are contaminated with PCBs, PAHs and toxic metals. Ostrich Bay, an embayment off Dyes Inlet, was the site of a Naval Ordnance facility where munitions were manufactured and destroyed, with by-products washed and dumped into the bay. In addition to industrial pollutants, agricultural and recreational uses of the surrounding land introduce their own contaminants, particularly fecal coliform, phosphorus and metals. This study utilized foraminifera to assess the condition of the benthic ecosystem. Thirty-five sediment samples collected by the Washington Department of Ecology (WADOE) were analyzed for their foraminiferal assemblages which were then correlated with data on sediment quality and chemistry. Of those samples, 20% were barren of foraminifera, and in the rest, species richness was relatively low, averaging four species per sample. The Shannon diversity index also indicated low diversity, averaging 0.99. Many samples contained large percentages of calcareous foraminifera that showed signs of dissolution. Samples that were barren of foraminifera and those that showed pronounced dissolution displayed high levels of Total Organic Carbon (TOC); the decomposition of organic material may well have resulted in anoxic conditions and low pH. The former may explain the lack of foraminifera in samples, and the latter may be responsible for the dissolution of foraminiferal tests. Comparison of foraminiferal diversity and toxic metal concentrations demonstrated a negative correlation between the two. Several samples in both inlets contain numerous euhedral crystals of gypsum. These samples displayed high TOC and were either barren of foraminifera or showed very low diversity. Analysis of sulfur isotopes indicate the gypsum is the result of sulfate reduction, either from decomposition of organic matter or from industrial processes. Thus, foraminiferal assemblages in marine waters surrounding Bremerton are responding markedly to conditions in the sediments, establishing the efficacy of using foraminifera as a tool for monitoring benthic ecosystems in Puget Sound.