Water Resources Research Act Program

Details for Project ID 2007IL161B

Methylmercury Bioavailability and Dynamics in the Streams of Piasa Creek Watershed: New Methods of Sampling and Analysis

Institute: Illinois
Year Established: 2007 Start Date: 2007-03-01 End Date: 2009-08-31
Total Federal Funds: $39,954 Total Non-Federal Funds: $79,912

Principal Investigators: Robert Hudson

Project Summary: Managing the exposure of the general population to Hg pollution has become a significant public concern, a concern validated at least in part by the fact that eight percent of women of childbearing age in the U.S. have Hg in blood above the US EPAs reference level (Schober et al., 2003), The focus of this concern has been on the occurrence of excess Hg in aquatic ecosystems and its effects on the health of humans and wildlife that consume fish. It is clear that there exists a knowledge gap about Hg contamination in Illinois surface water resources. In particular, relatively little is known about the levels of MeHg the most potent neurotoxin of all the Hg species and the only form of Hg that biomagnifies in aquatic food webs  in rivers and streams draining agricultural watersheds. Thus, little basis exists for predicting the benefits of emissions reductions in the main class of aquatic ecosystems in Illinois: riverine or lotic ecosystems.

Herein, we propose to begin filling this void by conducting a study of Hg and MeHg levels in water and aquatic food webs of a small, mixed land use watershed in western Illinois. The proposed field study will serve several purposes:
1) The study expands our knowledge of the hydrologic factors influencing MeHg levels in Illinois rivers and streams.
2) The study will test a newly-developed approach termed diffusive gradients in thin films or DGT for sampling bioavailable MeHg that, if successful, will help reduce the cost of monitoring MeHg levels in surface water systems. DGT results will be compared to measurements of MeHg in crayfish. Both are intended to give a location-specific measure of MeHg in prey items for fish and approaches are suitable for implementation by employees of state agencies with only limited training in ultraclean protocols.
3) The study will include synoptic surveys designed to investigate in-stream sinks of MeHg so that we can determine whether landscape-scale investigations of Hg pollution effects can focus solely on identifying likely sources of MeHg or whether both sources and sinks must be considered.

The study will be conducted in cooperation with faculty and undergraduate students from Lewis and Clark Community College in Alton, IL involved in the National Great Rivers Research and Education Centers summer intern program. The continuation of this successful collaboration will maximize the benefit of funds obtained using this grant and provide additional educational opportunities to young scientists.