Statewide Survey Finds Fish-Eating Birds At Risk from Mercury in Many Lakes

As part of the statewide bioaccumulation monitoring program led by Jay Davis of SFEI, SWAMP has released findings from the first statewide survey of contaminants in wildlife from California waters. The survey found that mercury concentrations in the blood of two closely related species of grebes were high enough to potentially translate to harmful impacts on their reproduction in over half of the 25 lakes sampled. The findings are summarized in a fact sheet, a technical report (Estimating Exposure of Piscivorous Birds and Sport Fish to Mercury in California Lakes Using Prey Fish Monitoring - A Predictive Tool for Managers) and a journal article in Environmental Science and Technology.

The study:

• evaluated mercury risk to wildlife (fish-eating birds) in a representative sample of California lakes,
• documented correlations between concentrations of mercury in birds and fish and developed a spreadsheet tool that can be used to estimate risk to birds in lakes where fish data are available, and
• established methods for monitoring birds and fish in lakes to estimate mercury risk to wildlife.

The study was the subject of an article in the Santa Rosa Press Democrat that was subsequently picked up by several other newspapers.