Date of Graduation


Document Type


Degree Type



Davis College of Agriculture, Natural Resources and Design


Agricultural and Resource Economics

Committee Chair

Patricia Mazik

Committee Co-Chair

Vicki Blazer

Committee Member

Kyle Hartman

Committee Member

Scott E Pruitt

Committee Member

Stuart Welsh


The Natural Resource Damage Assessment (NRDA) program is authorized by the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) and the Oil Pollution Act (OPA) to pursue compensation for injury to, or destruction and loss of, natural resources. Fish are an important "natural resource" present in almost all aquatic ecosystems. Polychlorinated biphenyls (PCBs) are a hazardous substance and have been shown to cause harm to fish (and fish-eating animals). A series of investigations were conducted to determine if "injury" had occurred to creek chub (Semotilus atromaculatus) and in one study, the fish community that creek chubs were a part of, at several PCB-contaminated study locations. We examined: hepatic condition and oxidative stress enzymes; a comprehensive look at reproductive condition; age and growth; and several metrics of fish community structure and function. Although the determination of hepatic oxidative stress is a response to PCBs, this in and of itself is not considered injury. However, it is a good biomarker of potential injury especially in the presence of other injuries, like reproductive failure. Consistent with the PCB toxicity literature, we consider hepatomegaly and lipidosis injuries that result from PCB exposure. Given that other common factors can also cause lipidosis, this is not an effective injury assessment tool. The age and growth analysis shows significantly reduced survivorship in females at the PCB sites; this is clearly an injury. Aspects of creek chub reproduction have also been adversely impacted: reduced vitellogenin (Vtg), altered sex steroid ratios, reduced fecundity, delayed/ impaired spawning of ova, and reduced / impaired testes maturation. Although not an injury per se, the reduced and seasonally altered pattern of the male secondary sex characteristic nuptial tubercles provides another line of evidence that neuroendocrine disruption is occurring at the PCB-contaminated stream sites. An assessment of the fish community at these PCB-contaminated streams also indicated that growth and survival were issues for the entire fish community. From Frye's standard of evidence [Frye v. United States, 293 F.1013 (D.C. Cir. 1923)], much of this work would have been extremely useful to trustees in court. What we found would be "generally acceptable" in our professional sphere. But scientists and lawyers look at facts differently: same language, same word, different meaning. The science of reproduction impacts is very complicated, and some aspects (i.e. neuroendocrine disruption) while clearly injury, are too complicated to prevail in the courtroom. The impacts to reproduction, including reduced vitellogenin (Vtg), reduced fecundity and delayed/ impaired spawning of ova have significant ecosystem consequences. Growth effects that follow a non-monotonic non-standard dose response curve would do poorly in court. While reduced survivorship should easily be translated to the injury known as "death", nothing in court is certain. Because it is extremely difficult to put a value on natural resources, it is very important to do whatever can be done early on to avoid litigation. A complete win on "injury determinations" (albeit unlikely), could still result in little or no restoration relief.