Toxicity in Sinclair and Dyes Inlet sediments as indicated by benthic foraminifera.
Presentation 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.
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.)
Document Type
Event
Start Date
1-5-2014 5:00 PM
End Date
1-5-2014 6:30 PM
Location
Room 6C
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)
Foraminifera--Effect of water pollution on--Washington (State)--Sinclair Inlet; Water--Pollution--Washington (State)--Sinclair Inlet; Contaminated sediments--Washington (State)--Sinclair Inlet; Sedimentation and deposition--Environmental aspects--Washington (State)--Sinclair Inlet; Foraminifera--Effect of water pollution on--Washington (State)--Dyes Inlet; Water--Pollution--Washington (State)--Dyes Inlet; Contaminated sediments--Washington (State)--Dyes Inlet; Sedimentation and deposition--Environmental aspects--Washington (State)--Dyes Inlet
Geographic Coverage
Salish Sea (B.C. and Wash.); Sinclair Inlet (Wash.); Dyes Inlet (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
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.
