PM01 Amphibian Research and Monitoring
Exhibit Hall
8:00 AM - Monday, 10 November 2003
(PM018) Water Quality of Surface-Water Microlayers at Frog Malformation Sites in Minnesota.
Jones, P1, Menheer, M1, Krabbenhoft, D2, Taylor, H3, Aiken, G3, Zaugg, S4, Rostad, C4, Thurman, E5, Rosenberry, D4, 1 U.S. Geological Survey, Mounds View, MN, USA2 U.S. Geological Survey, Madison, WI, USA3 U.S. Geological Survey, Boulder, CO, USA4 U.S. Geological Survey, Denver, CO, USA5 U.S. Geological Survey, Lawrence, KS, USA
ABSTRACT- Grab, near-surface, and microlayer (top 1 mm of surface water) samples were collected to determine relationships between frog malformation rates and the quality of surface microlayer and deeper waters. Samples were collected during June, August, and October 2001, and April 2002 at two sites where frog malformation rates were greater than 5 percent, and at two sites where frog malformation rates were less than 1 percent. Grab samples were obtained throughout the water column, and near-surface-water samples were collected through Teflon tubing held at the water surface. A radio-controlled catamaran sampler collected hydrophobic, microlayer samples using a rotating Teflon-coated drum. Samples were analyzed for major ions, trace elements, nutrients, total mercury, methylmercury, dissolved organic carbon (DOC), pesticides, hormones, and waste-water constituents. Trace element, total mercury, methylmercury, and average total DOC concentrations were elevated in microlayer samples relative to grab and upper-surface-water samples. No relationships were apparent between water-quality results and frog malformation rates.
Key words: frog malformations, amphibians, water quality, surface microlayer