Assessing Effects of Metal Mining Effluent on Fathead Minnow (Pimephales promelas) Reproduction in a Trophic-Transfer Exposure System

Abstract

Assessment of effects of metal mine effluent (MME) on aquatic organisms in lab-based settings predominantly evaluates contaminant transfer through the water only with little emphasis on food-borne exposure. The effects of MME on fathead minnow (Pimephales promelas) (FHM) have been reported downstream of metal mine discharges in the Junction Creek system, Sudbury, ON, but to date, no study has investigated the significance of trophic transfer in this system. Our objective was to develop a self-sustaining trophic-transfer bioassay, using Chironomus tentans and FHM, that allowed assessment of the effects of 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 assessed for 21 days under controlled laboratory conditions to obtain baseline data of various endpoints, including egg production and hatching success. Exposure to 45% (v/v) Copper Cliff mine effluent (CCME) and control treatments for both 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 reduced compared to controls. It was only in the trophic-transfer system that a significant reduction in larval hatching and an increase in deformities occurred after exposure to CCME. This would suggest that contaminated food was a route of exposure causing effects on larval survival.

The use of field-based mesocosm systems to assess the effects of uranium milling effluent on fathead minnow (Pimephales promelas) reproduction

“…While this may focus the experimental design, the conclusions can be misleading and of lower relevance to the actual ''real'' environment as no single mine or mill discharges a single metal or element. Based upon the experience in our laboratory with multiple effluent mixtures (Dubé and MacLatchey 2002;Hruska and Dubé 2004;Dubé et al 2006;Rickwood et al 2006c) we strongly recommend any investigations of whole effluent mixtures include a treatment of exposure to the mixture so any single metal treatments can be compared to the mixture response. A failure to do so lends itself to simplifying a mixture and its potential regulation to a few single metals which may not hold sole responsibility for the observed effects.…”

Copper and nickel speciation in mine effluents by combination of two independent techniques

“…The lowering of ı was probably due to the high stirring rate. The stirring rate was kept at a rate similar to the flow rate (0.24 L h −1 ) used by Dube and co-workers [15] to mimic the discharge of mine effluents in order to have similar diffusive boundary effects of DGT devices.…”

“…It is evident (from Eq. (15)) that under the same kinetic detection window, thereby defining the measured species as follows. DGT labile = CLE dyn , when, D M = D ML .…”

Investigating the link between pulp mill effluent and endocrine disruption: Attempts to explain the presence of intersex fish in the Wabigoon River, Ontario, Canada

“…We conducted a one-way ANOVA comparing our reference fish to the reference fish from four other studies including Rickwood and Dubé [20], Rickwood et al [21], and Rickwood et al (unpublished data). In making our comparisons we chose to examine egg production as it is considered the most sensitive endpoint [19].…”

“…Presence and magnitude of secondary sexual characteristics were based on the judgment and experience of the observer (same observer used for all fish at all checks). The scale used to score characteristics was identical to the work of Rickwood et al [20,21].…”