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. �����C-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 ��g/L +/- 56, 1 h mean reburial EC50=138 +/- 36. The predicted LC50 for NP (202 ��g/L) from an amphipod-derived structure-activity relationship was not significantly different (p>0.05) from our empirically derived LC50 (227 ��g/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 ��g/L significantly induced Vtg in fry following 5 d exposures. The 240 ��g/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. / Graduation date: 2003

Thesis (M.E.S.)--The Evergreen State College, 2008. / Title from title screen (viewed 2/25/2010). Includes bibliographical references (leaves 95-101).

Thesis (M.E.S.)--The Evergreen State College, 2001. / Title from title screen viewed (3/20/2008). Includes bibliographical references (leaves 41-44).

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 46-51). Also available on the World Wide Web.

Thesis (M.S.)--Washington State University, 2004. / Title from PDF title page (viewed on May 28, 2005). Includes bibliographical references (p. 149-158).

Digestible carbohydrate is commonly encountered by chinook salmon {Oncorhynchus tshawytscha) in practical culture diets, although little is known regarding its utilization. This study was undertaken to examine (1) the effects of a high carbohydrate diet and (2) glucose tolerance in chinook salmon of selected British Columbia strains. Yearling chinook salmon of three strains were fed to satiation either a high or a low carbohydrate diet for 63 days. The diets were isonitrogenous, and contained respectively 30 % gelatinized wheat starch or an equicaloric amount of herring oil. There was an overall reduction in growth of chinook fed the high-carbohydrate diet over the 63-day feeding period. Although specific growth rates declined initially in the high carbohydrate-fed groups, they were comparable to those of control groups in the final third of the trial, indicating an adaptation response. Chinook fed the high carbohydrate diet had increased carcass protein and ash, and decreased carcass fat levels relative to controls. Feed intake was generally lower in these groups, and differences in feeding response were observed between diets and strains. Although feed and energy efficiencies were reduced in chinook fed the high carbohydrate diet, protein utilization was comparable on the two diets, indicating a protein-sparing effect of the carbohydrate. Consumption of the high carbohydrate diet led to significant elevations in hepatosomatic indices (HSI) and liver glycogen (LG) concentrations. In Quesnel chinook, LG levels exceeding 10 % did not appear to have any detrimental effects on feeding, growth or health. LG concentrations and HSI fell to basal levels in all groups 21 days after feed withdrawal. Some strain differences were evident. For example, Big Qualicum chinook fed the high carbohydrate diet exhibited the lowest liver glycogen accumulation, highest rate of carcass fat deposition, and best energy efficiency ratios relative to control groups, suggesting a difference in carbohydrate metabolism in this strain. On the other hand, Quesnel chinook exhibited the highest relative growth on the high carbohydrate diet. Mortality, although unaffected by diet in the Quesnel and Robertson Creek chinook, appeared to be higher in high carbohydrate-fed Big Qualicum chinook. In the second part of the study, chinook salmon subjected to an oral glucose tolerance test displayed pronounced and persistent hyperglycaemia, indicative of poor glucose tolerance. Strain differences were evident in the magnitude of response. Acclimation to a high carbohydrate diet prior to testing resulted in a significantly reduced elevation of blood glucose, indicating an adaptation response. While plasma glucose concentrations approached 500 mg/dl in some trials, plasma insulin concentrations exhibited a two-fold rise, with indistinct peaks. Plasma glucose and plasma insulin concentrations were poorly correlated, indicating that glucose is a poor insulin secretagogue in chinook salmon. / Land and Food Systems, Faculty of / Graduate

Graduation date: 2002

Although differences between selective pressures in hatcheries and streams have been theorized to cause genetic divergence between hatchery and wild salmonids, evidence of this is lacking. This study was initiated to document the presence or absence of genetic change in hatchery and wild stocks by characterizing genetic traits in fish of various life history stages within a single generation. Nine biochemical traits (enzyme loci) and 12 meristic traits were characterized for adult fall chinook and one or more juvenile stages of their progeny of the 1984 brood year. Study groups consisted of hatchery-reared and naturally-reared subunits of populations in two tributaries of the lower Columbia River: Abernathy Creek and the Lewis River. Parents of both groups from Abernathy Creek were primarily of hatchery origin, whereas parents of both groups from the Lewis River were primarily of wild origin. The experimental design thus included reciprocal comparisons of hatchery and wild-reared groups from each of two stocks: one that has been propagated under hatchery conditions for at least five generations and one that has evolved in a stream environment. Both biochemical and meristic traits varied among adult and juvenile stages within hatchery and wild groups. Changes in some of these traits appear to have been caused by natural selection. This was true even for Abernathy hatchery and Lewis wild groups, which have been in the same environment for many generations. The direction and/or degree of change in some biochemical and meristic traits differed between hatchery and wild groups from a given stream, suggesting that selective pressures of the hatchery and wild environments differed in those cases. However, it could not be determined from these data whether the observed divergence of traits reflects general differences in hatchery and stream environments, or if it reflects population-specific responses to site-specific environmental conditions. The extent to which patterns of genetic change within a single generation might vary among year classes or generations is likewise unknown. Evidence of temporal changes in biochemical and meristic traits of hatchery and wild fish within a single generation has important implications regarding the use of those traits to characterize stocks. Assumptions of temporal stability of biochemical or meristic traits within or between year classes should be applied with caution. Sampling strategies of studies involving these characters should account for the possibility of temporal heterogeneity. Finally, these results suggest that workers using allozymes as genetic tags should test the assumption of selective neutrality of the particular allozyme markers being used. / Graduation date: 1991

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 80-94). Also available on the World Wide Web.

Thesis (M.S.)--Humboldt State University, 2009. / Includes bibliographical references (leaves 43-47). Also available via Humboldt Digital Scholar.