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 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.
Ongoing research projects in my lab include: investigation of the effects of wood-derived phytoestrogens and their mechanisms of action on gonadal steroid biosynthesis in goldfish; the use of the mummichog (Fundulus heteroclitus), rock gunnel (Pholis gunnellus) and other fish species as indicator species for environmental effects in Saint John Harbour waters (a system exposed to treated and untreated municipal sewage, pulp and paper mill effluents, refinery and brewery wastes, etc.) and tributaries; the effects and mechanisms of action of EDSs on growth and growth hormones in smolting Altantic salmon (Salmo salar); the development of a life-cycle assessment bioassay using mummichog to detect contaminant effects; the development of a portable, land-based flow-through mesocosm (artifical stream) system for field-based assessments of fish health; development of laboratory protocols to investigate the effects of various pulp and paper mill effluent process streams on mummichog and fathead minnow (Pimephales promelas) reproductive endocrine status; and the use of fish and fish parasites to identify freshwater ecosystems experiencing environmental stressors.
I am also keenly interested in international development issues, including technology transfer and education and training. I have ongoing projects in Cuba and South America to further develop research initiatives in Latin America.
The Lab participates as part of the national investigation of cause project which is presently determining the appropriate laboratory tests to be used to test for endocrine-disrupting contaminants active in pulp and paper mill effluents. More information about this project can be found at: