Are toxic ionic aluminum concentrations increasing or decreasing in high priority salmon rivers in Nova Scotia

Ionic aluminium (Ali) is toxic to Atlantic salmon and is known to be a key cause of population declines. Widespread increases in total aluminum concentrations in Nova Scotia have been discovered and the concentrations of toxic ionic aluminum species (Ali) currently exceed thresholds for aquatic health). Total aluminum (Alt) consists of Ali + organically complexed aluminum (Alo). A critical knowledge gap remains: is Alo driving the Alt trends and Ali levels staying stable or decreasing? Or are Ali levels increasing as well?  This project will answer this question by extend Ali monitoring programme in four key indicator NS Rivers, using models calibrated to field observed Ali concentrations to project Ali trends, and compare speciated trends with monitored catchments in Northeastern USA to see if NS rivers are behaving differently from these rivers which do not show a strong increasing Ali or Alt trend.

Contact: Dr. Shannon Sterling, 902-494-7741, Shannon.sterling@dal.ca