Form Submission: Participation Entry

Iron is an essential micronutrient; it can act as both a limiting nutrient or a toxicity threat in aquatic systems, and regulates the biogeochemistry, bioavailability, and transport of numerous compounds. Iron export from rivers has been shown to only be significant in the presence of dissolved organic matter (DOM). Our study addresses the role of DOM in iron cycling in the Connecticut River, a large temperate river with significant urban influence. We sampled five sites along a ~220 km stretch of the CT River from Northfield, Massachusetts to Old Lyme, Connecticut, bi-weekly. Initial results show that iron and DOM co-vary, and DOM allows for high iron concentrations to persist even when environmental conditions predict low iron solubility. Iron and DOM concentrations both increase in the sites immediately downstream of major urban areas (i.e., Springfield, MA and Hartford, CT), indicating a significant urban influence on iron and DOM cycling.