Ambient concentrations of elemental metals (e.g., cadmium, cobalt, lead, nickel, lead, zinc) from "natural" sources have been augmented by releases from mining and ore processing activities in areas adjacent to some national parks within the Heartland Network (HTLN). Although lead does not accumulate to high concentrations in organisms, effects including biochemical responses to lead in fish and altered benthic fish and invertebrate community composition have been associated with the release of metals from lead belts (for example Dwyer and others, 1988; Schmitt and others, 1984, 1987, 1993; Allert and others, 2004).
The National Parks Omnibus Management Act of 1998 requires park managers to know the condition of and conserve the natural resources within their parks. Accordingly, managers need to define and track concentrations of contaminant metals and possibly other potentially toxic elemental contaminants within the park, for both human health and ecological concerns. These needs may become more acute if additional economically significant lead-zinc deposits are located and exploited. To provide park managers with long-term data on elemental metal concentrations, HTLN implemented a monitoring protocol (developed by the U.S. Geological Survey in cooperation with HTLN) at Ozark National Scenic Riverways and Buffalo National River. Data collection in other parks located within HTLN may be added in the future.
Monitoring Questions & Approach
- What are the current levels of lead and other metals in the rivers of the park?
- Are metals concentrations increasing?
- Are river biota exposed to potentially toxic concentrations of lead or other elemental contaminants?
- Are individuals and populations of metal-sensitive river biota potentially being affected by metals exposure