Great Lakes beachgoers could spend a lot more time in the water if a beach forecasting tool under development by University of Michigan researchers and their colleagues is adopted throughout the region. The new forecasting tool would significantly reduce the number of days that Great Lakes beaches are unnecessarily closed to swimming due to inaccurate assessments of E. coli bacteria levels, according to David Rockwell of the U-M School of Natural Resources and Environment. "My estimate is that 23 percent of the time that swimming is prohibited at Great Lakes beaches due to high bacteria levels, those decisions are actually mistakes," said Rockwell, beach water quality forecasting coordinator at the Cooperative Institute for Limnology and Ecosystems Research (CILER), a collaboration between the U-M and the National Oceanic and Atmospheric Administration.