Grant: Strategic Projects - Group

Industrial and municipal discharges, such as pulp and paper mill effluents and sewage, contain compounds known as "endocrine disruptors". These compounds have chemical structures which make them able to mimic fish hormones, such as estrogen and testosterone. When fish are exposed to the endocrine disruptors, their normal hormone systems are altered. This can result in effects such as smaller ovaries and testes, "intersex" (in which both ovary and testis tissue are in one gonad), lower blood levels of reproductive hormones and changes in the numbers of offspring produced. Our project is focused on understanding how endocrine disruptors released into Canada's coastal environments interfere with normal functioning of fish reproductive systems. We will study how a common east coast saltwater minnow, the mummichog (Fundulus heteroclitus) is affected by endocrine disruptors in pulp mill effluents and sewage. We know much less about effects of endocrine disruptors in marine environments compared to freshwater systems. Because coastal environments have changes in water salinity, temperature and oxygen on a daily basis, we will first focus on understanding how changes in these variables, combined with the presence of endocrine disruptors, affect how fish are exposed to the chemical disruptors and how the fish's reproductive biology is changed. We will then design a standardized laboratory test using mummichog which can determine how potent certain effluents are in causing reproductive changes. This test can be used to determine the effectiveness, for example, of process changes made by industry to improve effluent quality. The test can be used by other research groups, government agencies, industries and consulting companies to test the quality of effluents. We will work with government regulators, industries, municipalities and citizen groups to ensure that our test meets regulatory needs and will be effective for effluent testing. A biological test that measures the sum total of endocrine disruption effects in complex effluents released into complicated marine receiving environments will be of significant value in protecting Canadian coastal environments from this form of aquatic contamination.