At present, little metal speciation information exists for most parts of the Yukon. The current database of knowledge is largely based on research from southern stream environments which tend to be warmer than Yukon streams. This presents a challenge for regulators and practitioners interpreting data from northern systems using guidance that is developed and defined by southern baseline data and effects. This study was designed using a preliminary approach to assist in filling the current information gap. The Selwyn Basin in the Yukon has natural elevated concentrations of metals including arsenic, mercury and selenium (EDI 2008, Gartner Lee 2007). Water quality studies that have been conducted within the Selwyn Basin have not considered the importance of metal speciation and changes in mobility and exposure to aquatic organisms inhabiting lotic watercourses likely impacted by both naturally elevated and anthropogenic (mining related) metal input sources. The objective of this project was to increase the understanding of metal speciation in relation to surface water and sediment metal concentrations within the Selwyn Basin at six discrete lotic watercourse sites over two seasons.
