Using multiple artificial DNA tracers in hydrology

Abstract

AbstractTracer testing is an efficient and versatile method to characterize hydrological processes both in surface waters and in the subsurface, and with synthetic DNA (deoxyribonucleic acid) experiments can be performed with a theoretically unlimited number of tracers. We explored the use of six synthetic DNA tracers in injection experiments in the Strijbeekse Beek and the Merkske, two small brooks in the Netherlands. We wanted to test the applicability of synthetic DNA markers in combination with the quantitative polymerase chain reaction (qPCR), an analytical technique used to determine DNA concentrations. The most important results from the two experiments were that DNA concentrations during breakthrough ranged from 0·1 to 100 fM (femtomolar = 10−15 mol/l), and that DNA mass transport in the stream was not retarded compared to transport of an injected NaCl mass. However, DNA mass was substantially reduced, most likely as a result of adsorption, attachment, decay and/or biological uptake processes in the stream itself. Although more insight in the various mass balance components of DNA mass in the stream is required, we concluded that the use of synthetic DNA markers in combination with qPCR has potential for spatially distributed surface water‐groundwater interaction tracer experiments. Copyright © 2011 John Wiley & Sons, Ltd.