PARENT SESSION
PT5 - Fate & Effects of Metals: Aquatic Biology
Tuesday, 19 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P643) Cumulative impacts on caged fish of gold mine and municipal wastewater effluents and of garbage-disposal run-off.
Klaverkamp, Jack*,1, Palace, Vince1, Baron, Chris1, Evans, Robert1, Wautier, Kerry1, 1 Department of Fisheries and Oceans Canada, Winnipeg, Manitoba, Canada
ABSTRACT- Over an 8 kilometer stretch of Balmer Creek in northwestern Ontario, resident fish are exposed in sequence to 3 major sources of contaminants; namely, treated effluents from 2 gold mines (TGME), treated discharges of municipal wastewater (TMWW), and run-off from a garbage disposal facility (GDRO). Mean concentrations of As, Cu, Hg, Ni, Pb, Se, Zn and Cd in exposed surface sediments (1 cm) along this stretch are approximately 61, 43, 26, 15, 12, 11, 9 and 4 times higher, respectively, than corresponding concentrations at reference sites. In preliminary experiments, fathead minnows (Pimephales promelas) exposed to the cumulative 3 sources had significantly higher concentrations of metallothionein (MT), As, Cu, Zn and Ni in their viscera. To determine the cumulative effects of contaminants from the 3 major sources, pearl dace (PD, Semotilus margarita) were placed in cages for 14 days at locations along the stretch and at a reference site. Mean MT and Zn concentrations in viscera were lowest in PD exposed only to TGME and higher in PD at sites immediately downstream of the TMWW site. Visceral concentrations of As and Ni were highest in PD immediately downstream of TGME discharges. Visceral Ni concentrations were lowest in the site downstream of GDRO, whereas similar As concentrations remained significantly higher compared to the reference site. LSIs were higher in female PDs exposed to TMWW. Mean GSIs of females were lowest in PDs exposed to TGME and highest in PDs exposed to TMWW. Histological analyses of tissues and concentrations of vitamins A and E in tissues and of vitellogenin in plasma also provide infromation regarding cumulative impacts on these caged fish.
Key words: metallothionein, fish, caged, cumulative impacts