Continuous monitoring to assess phosphorus dynamics and ecological status in the River Kennet, UK

Introduction The links between ecological status of lowland rivers and diffuse and point-source nutrient inputs are of key scientific importance under the EU Water Framework Directive (WFD) (EU, 2000). Many previous studies on the sources and effects of phosphorus in rivers have been based on weekly, storm event or even monthly sampling. However phosphorus concentrations are sensitive to a wide range of shortterm dynamics and diurnal cycles that are not captured by conventional sampling programmes. Hence phosphorus loads may be under estimated and valuable information about the variability in P concentrations and links with in-stream processes and ecology may be missed. In this study, we use in-situ ‘continuous’ (hourly) measurements of total reactive phosphorus (TRP; unfiltered molybdatereactive P), chlorophyll, dissolved oxygen (DO), conductivity, turbidity and flow to examine dynamics in P concentrations and sources and ecological status for the River Kennet, a lowland chalk river in south east England.