Dave Krabbenhoft discusses his career of mercury research

Dave Krabbenhoft discusses the history of his 28-year career at the USGS.  He describes how he started working on mercury research in the 1980s, trying to unravel the mystery of why mercury was being detected in fish in pristine lakes in Northern Wisconsin, and how that research has evolved over time to determine atmospheric mercury is the primary source of mercury pollution in those pristine ecosystems.