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Accumulation and effects of 4-nonylphenol in chinook salmon fry and their estuarine amphipod prey

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dc.contributor.advisor Jepson, Paul C.
dc.creator Hecht, Scott A.
dc.date.accessioned 2012-07-17T18:13:21Z
dc.date.available 2012-07-17T18:13:21Z
dc.date.copyright 2002-08-09
dc.date.issued 2002-08-09
dc.identifier.uri http://hdl.handle.net/1957/31141
dc.description Graduation date: 2003 en_US
dc.description.abstract 4-nonylphenol (NP), a surfactant degradation product, is an unregulated, ubiquitous aquatic contaminant and endocrine disruptor, for which aquatic life criteria are currently under development by U.S. EPA. The effects of NP on estuarine amphipods and chinook salmon fry were investigated, and this dissertation reports research into the impacts of NP bioaccumulation on the amphipods and resultant endocrine disruption of their juvenile salmon predators. Sensitivity to, and bioaccumulation of, NP by benthic amphipods were quantified. Factors affecting the bioavailability of NP to three species of amphipod (Eohaustorius estuarius, Grandidierella japonica, and Corophium salmonis) were determined in contaminated sediments. Standard bioassay techniques were modified to determine toxicity and bioaccumulation, with varying amounts and differing nutritional qualities of sedimentary organic carbon. ¹⁴C-Ring-labeled NP was used as a tracer in the experiments to quantify amphipod exposures. NP was acutely toxic to Eohaustorius estuarius from aqueous exposures, mean (+/-SD) LC50=227 μg/L +/- 56, 1 h mean reburial EC50=138 +/- 36. The predicted LC50 for NP (202 μg/L) from an amphipod-derived structure-activity relationship was not significantly different (p>0.05) from our empirically derived LC50 (227 μg/L). All three amphipod species accumulated significant NP body burdens. Accumulation was inversely proportional to the total amount of organic carbon, but it did not differ between types of organic matter. Calculated accumulation factors indicated that amphipods could be an important and previously unrecognized source of NP to higher trophic levels. Plasma vitellogenin (Vtg) was quantified in juvenile chinook salmon following dietary exposure to NP contaminated amphipods and aqueous exposure to multiple NP concentrations. Fry that had fed upon contaminated amphipods did not have significantly greater Vtg levels than controls; however, Vtg was detected in 30 percent of fry. NP aqueous concentrations at 60 and 240 μg/L significantly induced Vtg in fry following 5 d exposures. The 240 μg/L aquatic NP treatment fry had comparable levels of Vtg to the positive control treatment in which fry were injected 17B-estradiol. These results indicate that amphipods are potential vectors of sediment NP to higher trophic levels within the water column, including juvenile chinook salmon. en_US
dc.language.iso en_US en_US
dc.subject.lcsh Chinook salmon -- Effect of water pollution on en_US
dc.subject.lcsh Chinook salmon -- Endocrinology en_US
dc.subject.lcsh Amphipoda -- Effect of water pollution on en_US
dc.subject.lcsh Nonylphenol -- Toxicology en_US
dc.title Accumulation and effects of 4-nonylphenol in chinook salmon fry and their estuarine amphipod prey en_US
dc.type Thesis/Dissertation en_US
dc.degree.name Doctor of Philosophy (Ph. D.) in Toxicology en_US
dc.degree.level Doctoral en_US
dc.degree.discipline Science en_US
dc.degree.grantor Oregon State University en_US
dc.description.digitization File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0.82 on a Canon DR-9080C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR. en_US
dc.description.peerreview no en_us


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