Development of an isotopic/elemental assay to identify diadromy in brook trout and its influence on coastal stream ecosystems

Kinnison, Michael; Simon, Kevin; Coghlan, Stephen

From project description: "Maine is considered one of the last strongholds of natural brook charr populations in the United States, harboring numerous lacustrine and riverine populations (Bonney 2006; Hudy et al. 2008). However, assessment of brook trout status in Maine has focused largely on these inland populations, neglecting the status of diadromous populations. Anglers consistently report perceived declines in diadromous populations, potentially coincident with declines in geographically proximate areas of Massachusetts (Mass. Dept. Fish. and Wildlife) and Atlantic Canada (Curry, R. A. Canadian Rivers Institute, pers. comm.). Such reductions could indicate limitations associated with current management and the health of small coastal stream ecosystems including their associated marine linkages. We believe these fish may represent an excellent focal species for assessing the health and connectivity of coastal streams and estuaries, but diadromous populations are poorly documented in Maine and their ecology is even less clear. The goal of this project is to develop methods, including non-lethal approaches, to detect diadromy in brook trout and to begin exploring the influence that diadromous fish have on these small coastal ecosystems. We envision that these methods and data will allow us to conduct future, larger scale, surveys of the coast-wide prevalence of anadromous brook trout populations in Maine and their role in the health of coastal streams and marine habitats."