U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting Charleston South Carolina March 8-12,1999--Volume 1 of 3--Contamination From Hard-Rock Mining, Water-Resources Investigation Report 99-4018A

Characterizing the Aquatic Health in the Boulder River Watershed, Montana

By Aïda M. Farag, Daniel F. Woodward, Don Skaar, and William G. Brumbaugh.

This report is available in pdf format: farag.pdf 62KB

ABSTRACT

The Boulder River and some of its tributaries receive direct effluent from abandoned mine adits and runoff from old tailings piles located in the basin. This biological assessment identified a pathway of metals exposure in the Boulder River Watershed as measured by concentrations of metals in biofilm (abiotic and biotic material on rock surfaces), invertebrates, and fish collected from the Boulder River and a select number of its tributaries. These data along with data from fishery population surveys are being used to assess the ecological health of the Boulder River and its tributaries. Preliminary data suggest that concentrations of arsenic, copper, cadmium, lead, and zinc are elevated to varying degrees in biological tissues collected from the Boulder River and its tributaries. Tissue damage in fish livers, as measured by an increase of products of lipid peroxidation, along with reductions in fish sizes and populations in lower Cataract Creek were also noted. Thus, exposure to metals may have resulted in a deterioration of fish health and a quantitative loss in fish populations in Cataract Creek. We also documented 100% mortality of fish placed in live containers in the upper sections of the Basin Creek and Cataract Creek and lower High Ore Creek.