Evaluating changes in Water Chemistry as Risk Factors for Salmon in Downeast Maine

Statement of Critical State Water Problem:
The listing of Atlantic Salmon as an endangered specie is controversial for many reasons, most of which involve water. There is the question of water availability, enhanced due to the summer droughts in two of the past three years. Irrigation of blueberry fields and cranberry bogs is competing for the available water each summer. Non-point pollution is a factor as influenced by commercial logging operations in the salmon river watersheds. Acid rain has been implicated for both chronic acidification and for episodic acidification. Climate change is another potential factor, because salmon are at their southern limit already, and warming rivers could be detrimental.

An unexplored factor is the trend in water chemistry variables such as acidity, aluminum, dissolved organic carbon, and base cations. There are data from seepage lakes in the region that suggest systematic trends, but the data are not yet available for salmon rivers. This project will complete the collection of these data, and evaluate the existing data pertinent to the salmon issue.

Statement of Results and Benefits:
Two major water resource issues to be addressed in this research are potentially important for Atlantic Salmon: climate change and acidic deposition. While extrapolation of past trends is the trap that makes most predictions fail, an understanding of recent trends is necessary as the starting point for any predictions or planning. The determination of local trends is very difficult due to annual and seasonal variations, and lack of spatially distributed data. However, the response of ecosystems is likely to be an integrator of the various climatic factors. We propose that the response of forested watersheds may be a useful indicator of local climate change. The response of these watersheds also integrates the response to acid rain. The substantial long-term chemical databases in Maine have never been evaluated for this purpose.