The completion of environmentally relevant microcosm exposures for the validation of environmental quality standards (EQS) for drugs used in aquaculture

This project addresses the DFO priority related to the validation of environmental quality standards (EQS) i.e. thresholds for aquaculture drugs. The work related to this contract will entail the use of exposures reproducing contamination profiles measured in Canadian finfish sites through analysis of DFO data (output of Competitive Science Research Fund (CSRF) AQ-15-03 to be provided by D. Hamoutene). The contractor will have to set up long-term and intermittent exposures with different contamination profiles (to be determined by D. Hamoutene as previously indicated) on commercially and environmentally relevant species (American lobster, Rock crab, and Green sea-urchin). Exposures will be intermittent for lobsters and crabs, and continuous (6-8 months), for sea urchins. Sediments will be spiked with compounds at different concentration/enrichment regimes using formulated products and fish wastes. In particular, the contractor will have to secure access to the species listed above including, for lobsters, berried females. The contractor should have access to adequate tanks including recirculating seawater to complete these tasks including a facility where hazardous chemicals are approved for use.The work described in this contract will generate new data to be included to the toxicity endpoints to be used for EQS determination in order to propose updated thresholds and adequate assessment factors (AF) as well as strengthening the weight of evidence approach underlying EQS determination and validation. The combination of information on toxicity with effects mimicking real-world field data can allow a better evaluation of environmental risk and anticipate long-term effects on populations. Chronic effects of sediment contamination profiles (single or multi-chemical) with environmental relevance will inform on cumulative and sublethal effects on important marine species (especially on effects on female lobsters). Ultimately, information to be gained through this work will allow to better relate toxicity to field data and better address uncertainties in term of the appropriateness of AF and previously discussed thresholds (including internationally proposed values).