Grant: Discovery Grants Program - Individual

Contaminants are potential environmental stressors that enter watersheds as complex mixtures with differing properties that greatly influence their environmental fate and effects. Our current lack of understanding of interactions among chemical mixtures, other stressors and the natural environment creates considerable uncertainty when assessing environmental risk, especially when cumulative effects are considered across watersheds. Although major investments in wastewater infrastructure have greatly improved effluent quality associated with industrial and municipal wastewaters, many contaminants remain a major concern. For example, antidepressants remain elevated (i.e., mostly untreated) in municipal wastewaters that are released continuously into the receiving environment at relatively high concentrations. In addition, many of these recalcitrant contaminants and their metabolites have unique properties (e.g., chirality) with the potential to cause effects though subtle changes in fish reproductive behaviour and performance (not fully included in current risk assessments). A wide variety of potential contaminants also continue to rapidly emerge that may require modified approaches to assessing and controlling their risk in the future. The current research program will focus on representative chemicals of concern (i.e. chiral antidepressants and drugs of abuse) to advance and apply emerging technologies (e.g. mass spectrometry, transcriptomics, metabolomics) and novel bioassays to better assess environmental exposure, bioavailability and effects (i.e. risk) in a sentinel fish species, rainbow darter (Etheostoma caeruleum). Chemical mixtures and stressors remain a major challenge, especially when considering the complexity of different species and ecosystems and how they might respond to chemicals across watersheds. Adaptive biomonitoring therefore remains one of the best approaches to support assessment and management of cumulative effects. However, biological monitoring is still poorly developed at the watershed scale because of an inadequate understanding of natural variability and knowledge about how mixtures (e.g. effluents, runoff) and multiple stressors interact in the environment. This research program will therefore continue to develop and test techniques to effectively monitor for environmental change using fish populations as the primary model with the long-term goal of improving biomonitoring frameworks and risk management of contaminants. By advancing these two different but complementary approaches (risk assessment and adaptive biomonitoring) a new generation of highly qualified personnel (HQP) will be trained with the critical technical, interdisciplinary, and collaborative skills needed to address the pressing issue of managing cumulative effects at the watershed scale.