Metal Mining Effects on Aquatic Biota: North American and South American Examples and Perspectives

Metals have been crucial components of cultures for millenia, but their acquisition and use have multiple undesirable side effects.  In this talk, we focus on how metal mining has affected fish, macroinvertebrate, or diatom assemblages through use of case studies of mines in Montana (USA), Minas Gerais (Brasil), the High Andes (Bolivia), and Quebec (Canada).  Observed effects include reduced multimetric index scores, shifts from sensitive to tolerant taxa, reduced taxa richness, and reduced salmonid catch per unit effort.  We conclude that existing mining laws are inadequate for protecting or rehabilitating aquatic ecosystems.