Contaminants that can alter signaling of hormones are known as endocrine disruptors. These contaminants are of concern as they may impair reproductive function in wildlife, leasing to a population decline. Normally, hormones function at very low concentrations, so it is thought that even very low concentrations of such contaminants may be having an impact.

Vitellogenin is a protein precursor to egg yolk. Its synthesis is controlled by the hormone estrogen and has become a popular biomarker for chemicals that act as estrogen. Vitellogenin is not normally present in males due to the low levels of estrogen in their systems. The presence of vitellogenin in males is used as a sign that something in its environment may be able to act as estrogen. Thus, measurements of plasma vitellogenin in male fish can be used to detect unnatural estrogenic effects from pollution.

This project involves:

-Purifying vitellogenin form California halibut

-Developing an assay to measure plasma vitellogenin in halibut.

-Testing contaminants for the ability to alter vitellogenin synthesis