Transport of Dissolved Organic Carbon, Nutrients, and Trace Metals from the Wilson and Blossom Rivers to Smeaton Bay, Southeast Alaska

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Abstract
Regional and seasonal differences in chemical input from the Wilson and Blossom rivers, two pristine, major salmon-producing rivers in southeast Alaska, were examined. For a period of 2 yr, concentrations of dissolved organic carbon, nutrients, Cu, Fe, and Mn in the rivers were determined at approximately monthly intervals and used to calculate export rates. Because of extremely high annual precipitation (400–450 cm) and drainage basins restricted by high topographical relief, the concentrations and export rates of nutrients and Cu are low in the rivers for most of the year. The maximum nutrient export from the Wilson–Blossom system appears to be closely tied to the annual salmon cycle. Iron and Mn export rates from the watersheds are much higher than those for Cu, reflecting solubilization of Fe and Mn under reducing conditions that develop in muskeg ponds during drought periods. The association of metals with organics allows transport of Fe and possibly other metals throughout the fjord system, in contrast with the large-scale removal of metals in or near the river's mouth, as has been observed elsewhere.