Jeff Brown, Martha Sutula, Chris Stransky and John Rudolph. 0. 50. 100 ... Crow n Valley Riparian Da iry Mart Pond s. IRW. D Ca rlson. IRW. D Pond. 6. IRW.
Sediment Quality in Urban Wetlands Introduction
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Copper
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characterized for 21 freshwater urban wetlands and 2 reference sites in southern California. Sediments were collected at a location nearest to the primary source of urban runoff within the wetlands in order to characterize the greatest potential effect. All samples were analyzed for trace metals and organics (PCBs, PAHs, chlorinated pesticides and pyrethroid pesticides). These measurements were assessed by comparing the values to freshwater Probable Effects Concentrations (PECs), or mean LC50 values for pyrethroid pesticides. Toxicity was assessed using the Hyalella azteca 10-day survival test. Most locations that exhibited toxicity were subsequently testing with preliminary sediment TIEs. The TIE treatments for this evaluation specifically targeted pyrethroid pesticides, based on available chemistry data of the samples tested.
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kilometers Lewis Center Marsh
Old Mission Creek
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Bifenthrin
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The metal and chlorinated
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pesticide constituents that exceeded a sediment quality guideline tended to vary among the sites.
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L-Cyhalothrin
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Pyrethroid pesticide
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contamination (bifenthrin, Lcyhalothrin) was prevalent at most sites, with concentrations exceeding the average sediment LC50 by as much as a factor of 137.
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Arroyo Seco Ballona FW Marsh Big Canyon Marsh Big Canyon Riparian Brawley Wetlands Camino Real Bioswale Crown Valley Riparian Dairy Mart Ponds IRWD Carlson Marsh IRWD Pond A IRWD Pond 6 Lewis Center Marsh Madrona Marsh Mojave River Marsh Old Mission Creek San Elijo Marsh Sespe Creek Sims Pond UCI Pond 11 UCI Pond 3 Valeta Street Marsh Wet CAT East Wet CAT North
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Sediment Toxicity
Sediments from about half of
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the wetland sites were toxic to amphipod survival.
