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Pacific Islands Water Science Center
ABOUT THE PACIFIC ISLANDS WSC
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Oahu NAWQA: Bed Sediment and Fish Tissue
Stream bed sediment and fish tissue were collected from 26 streams on the island of Oahu to assess the occurrence and distribution of trace elements and hydrophobic organic compounds. Bed sediment was analyzed for 45 trace elements, 32 organochlorine compounds, 79 semi-volatile organic compounds, and organic, inorganic, and total carbon. Fish tissue was analyzed for 22 trace elements and 28 organochlorine compounds. All samples were analyzed at the U.S. Geological Survey's National Water-Quality Laboratory in Denver, Colorado.
NAWQA bed-sediment and fish-tissue studies evaluate trace elements and hydrophobic organic compounds in two stages. First, an occurrence survey is completed at a limited number of sites representing the various land uses within the study area to determine which constituents are important to water-quality conditions. Then, a spatial distribution survey is done to increase the geographic coverage with particular emphasis on the assessment of priority constituents identified in the occurrence survey.
U.S. Geological Survey Fact Sheet 140-00
Download Fact Sheet 140-00 PDF file.
Organochlorine pesticides were heavily used from the mid-1940s to the mid-1980s. The persistence of organochlorine pesticides, their tendency to accumulate in soil, sediment, and biota, and their harmful effects on wildlife brought this class of compounds into disfavor and eventually resulted in restriction or cancellation of most of them in the United States (Nowell and others, 1999). Despite use restrictions, these compounds continue to be detected in sediment and fish tissue samples.
This study was undertaken as part of the National Water-Quality Assessment (NAWQA) program of the U.S. Geological Survey (USGS). The NAWQA program assesses watersheds as integrated systems, focusing on chemical concentrations, physical conditions, and biological status in streams. One component of NAWQA is an occurrence survey of organic contaminants and trace elements in stream bed sediment and fish tissue.
The goal of the Oahu stream bed sediment and fish tissue occurrence survey was to determine which organochlorine contaminants are present in streams around the island, and with which land uses they are associated. An understanding of relations between land use and organochlorine compounds will allow land management practices to be designed to reduce the loading of contaminants to streams and nearshore waters.
For More Information
If you have questions and comments related to the Oahu NAWQA study, contact:
Stephen Anthony (email@example.com)
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