- Ashe, Wesley Craig
University of Maine Graduate School
The Machias River, Located in downeast Maine, harbors one of the few remaining wild populations of Atlantic Salman Salmon salar in the U.S. and provides a model system for investigating the productive capacity of headwater streams currently inaccessible to wild salmon because of impassable culverts. Historically, headwater streams provided high-quality nursery habitat to juvenile salmon as they encompass >70% of the total Stream Area in a watershed, and have more favorable and consistent temperature regimes, more available food and fewer predators than larger rivers. In spring 2010 and 2011, we stocked salmon fry in twenty study reaches and quantified survival and growth across multiple environmental gradients. Fry migration was quantified at representative sites with directional traps, where movement was invariably in a downstream direction, negligible in distance, away from suboptimal habitat, and predominantly within days of stocking.