Water Resources Research Act Program

Details for Project ID 2012CT259B

Influence of dynamic copper speciation on bioavailability in streams

Institute: Connecticut
Year Established: 2012 Start Date: 2012-03-01 End Date: 2014-02-28
Total Federal Funds: $31,507 Total Non-Federal Funds: $72,397

Principal Investigators: Timothy Vadas

Project Summary: Urban streams are dynamic systems with many anthropogenic inputs and stressors that impact their ecosystem functions, such as nutrient processing, flood control, and contaminant mitigation. Existing contaminant impairments are dealt with through total maximum daily load calculations that assess the maximum contaminant input a water body can receive in order to meet a specified water use and quality goal. Techniques for assessing that load are based on a combination of acute and chronic water quality criteria, biotic ligand models, and physical, chemical and biological assessments. However, discrepancies arise, and these assessment tools are based on correlative evidence with direct causal relationships not explicitly defined. I propose that Cu bioavailability is controlled by organic matter inputs to streams, particularly through dietary uptake, and an understanding of the mechanisms controlling Cu toxicity in streams will allow a more targeted, site specific analysis of Cu loads based on speciation measurements or alternative chemical and biological indicators which are quicker to deploy. This research will examine the use of diffusive gradient in thin film devices as well as a periphyton cultures as indicators of Cu impacts. In addition, the hypothesis that Cu bioavailability is controlled by carbon inputs will be examined in controlled laboratory studies with typical stream dwelling organisms, algae, mayfly and Ceriodaphnia. This information will be useful in understanding mechanisms of Cu impairment, potential alternative indicators that are easier to deploy and more revealing than total Cu concentrations or macroinvertebrate surveys, and will help direct mitigation options based on distinct carbon or metal inputs.