For decades, Adirondack resource managers have blamed the yellow perch for the decline of heritage trout strains, believing that perch were introduced to Adirondack waters in recent times and have been displacing the native strains from their historic habitat.But lake sediment core samples taken by Curt Stager and his students at Paul Smiths College yield DNA evidence showing that trout have been co-existing with perch for at least 2,000 years there. While perch are aggressive competitors and native trout are in decline, the reason for the change in balance likely lies in other factors yet to be determined.