A National Pilot Study of Mercury Contamination of Aquatic Ecosystems along Multiple Gradients (Krabbenhoft and others, 1999) was conducted from June to October, 1998 at multiple locations (3 to 8) in each of 21 NAWQA study basins, including the ALMN Study Unit. Nationally, these basins spanned the dominant east-to-west mercury deposition gradient and represented a wide range of environmental settings. The two primary objectives of the study were to provide multimedia data on mercury using standardized collection and analysis methods for ecosystems across the United States and to identify ecosystem characteristics associated with high production and accumulation rates of methylmercury.
Samples were collected at five sites throughout the ALMN Study Unit to perform in-situ measurements for the quantification of total mercury, methylmercury, pH, sulfate, dissolved organic carbon (DOC), and DOC fractionation. All samples were collected using the Part-Per-Billion protocol established by the USGS, Water Resources Division.
For more information on this National Pilot study, contact the project leader, Dave Krabbenhoft, a USGS Research Hydrologist (GeoChemist). He is located in the Middleton, Wisconsin USGS office and can be reached at (608) 821-3843.
A map showing the Mercury Synoptic sample locations is available for viewing: