My research primarily concerns contaminant effects on endocrine (hormone) systems in fish. I am interested in the effects, and mechanisms of action, of environmental endocrine disrupting substances (EDSs). EDSs are compounds that mimic the natural hormones of animals, thereby altering the normal functioning of endocrine systems which control important processes such as reproduction, development, and growth. There are widespread observations of endocrine-related effects in wild, caged and laboratory fish exposed to hormone-active compounds from a variety of sources, including sewage, oil & gas exploration, and pulp mill effluent. However, it is not known how EDS effects are manifested, including how effects are integrated and realized at different levels of biological organization and the extent of species differences.
Key research projects in my lab include: development of laboratory and field protocols to investigate the modes of action and effects of EDSs on endemic North American species, including mummichog (Fundulus heteroclitus) and fathead minnow (Pimephales promelas); understanding how environmental factors (e.g., temperature, dissolved oxygen, salinity, etc.) affect the availability, uptake and effects of EDSs in fish; and determining the source of, and potential remediation strategies for, EDS contaminants in pulp mill processing and sewage treatment. We study both model compounds (e.g., EDSs whose mechanisms are known, e.g., estrogen agonists) as well as mixed effluents with contaminants of unknown actions (e.g., pulp mill condensates).
Our laboratory is interested in linking the modes of action of EDSs at the molecular and physiological levels to population-level effects in reproducing and developing fish. For this reason, we use a suite of molecular and endocrinological tools, standard ecotoxicological methods, and chemical analyses to characterize the chemical and biological systems we want to better understand.