Biomonitoring in the mercury‐contaminated Wabigoon–English–Winnipeg river (Canada) system: selecting the best available bioindicator

Abstract

AbstractSeveral organisms used for biomonitoring in the mercury‐contaminated Wabigoon–English River System, Ontario, Canada (sport fish, forage fish, crayfish and others) were examined for their utility as bioindicators. Causes for spatial and temporal variability in mercury concentrations in biota are reviewed. The significance of intertrophic and intratrophic biotic relationships is evaluated on both a site‐specific and intersite basis. Larger mature fish are the most effective integrators as these organisms are the most buffered from site‐specific and seasonal variations in mercury concentrations and bioavailability. Where there are no physical barriers preventing movement of biota between contaminated and uncontaminated parts of the watercourse, younger, smaller organisms can better ‐ ical zones of contamination because of their restricted range. Because many organisms can provide information on mercury contamination, the choice of the most suitable indicator depends upon the purpose of the study, the pharmacokinetics of mercury uptake by the organisms in question, and the chemodynamics of methyl and inorganic mercury species in the field.