| Abstract
| - Assessment of effects of metal mine effluent (MME) onaquatic organisms in lab-based settings predominantlyevaluates contaminant transfer through the water only withlittle emphasis on food-borne exposure. The effects ofMME on fathead minnow (Pimephales promelas) (FHM) havebeen reported downstream of metal mine discharges inthe Junction Creek system, Sudbury, ON, but to date, nostudy has investigated the significance of trophic transferin this system. Our objective was to develop a self-sustaining trophic-transfer bioassay, using Chironomustentans and FHM, that allowed assessment of the effectsof not only water-borne (FHM-only) but also food- and water-borne (trophic-transfer) exposure to MME on FHM reproduction. Reproductive performance of FHM was assessedfor 21 days under controlled laboratory conditions toobtain baseline data of various endpoints, including eggproduction and hatching success. Exposure to 45% (v/v)Copper Cliff mine effluent (CCME) and control treatments forboth systems was then conducted for a further 21 days.It was evident that reproductive output in both the water-only and the trophic-transfer system was reducedcompared to controls. It was only in the trophic-transfersystem that a significant reduction in larval hatching and anincrease in deformities occurred after exposure toCCME. This would suggest that contaminated food was aroute of exposure causing effects on larval survival.
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