The Downeast Salmon Federation says it is monitoring what its biologist calls “a massive fish kill” on the Union River below Brookfield Asset Management’s dam in Ellsworth. Courtesy of Downeast Salmon Federation Courtesy of Downeast Salmon Federation The Downeast Salmon Federation is monitoring reports that thousands of tiny baby alewives are being killed as they swim downstream through or over the Ellsworth dam. The fish kill apparently began Tuesday, as thousands of baby alewives and other species unsuccessfully tried to swim downstream through or over the dam, said Brett Ciccotelli, a fisheries biologist for the federation. “The flow of the river has been full of dead or dying baby river herring, their scales, their fins, their eyeballs.