A new nitrate sensor worth $NZ50,000 has been installed in the Manawatū River to give Massey University and Horizons Regional Council scientists a more detailed picture of our river system dynamics and, ultimately, improve river management.
The specialised sensor has been brought in from Ireland by Professor Phil Jordan of Ulster University. He, together with Massey’s Institute of Agriculture and Environment senior lecturer Dr Ranvir Singh, senior research officer Lucy Burkitt, Horizons science and freshwater manager Dr Jon Roygard and senior catchment data coordinator Paul Peters, have installed the sensor at one of Horizons’ monitoring stations by the Fitzherbert Bridge.
The sensor works by shining ultraviolet light onto water samples collected periodically. The light excites the nitrate ions and reads the florescence given off by those ions. The data can be downloaded onto a computer or directly onto Horizons’ infrastructure, to be available on the web.
Dr Singh says it allow them to more accurately measure nitrate changes across days, weeks and seasons.
“Previously, water quality has been assessed by a technique called grab sampling, where a scientist will go out to the river, take a bottle of water and take it back to the lab to analyse. This sensor is doing the measurements in the field and much more often – up to every 15 minutes. We can then see how the dynamics of nitrogen flow change in the river over time. As we move forward with water quality management, there’s more and more of a demand for accurate and timely information.”
Dr Jon Roygard this technology has the potential to provide more accurate information in real time to Horizons’ website rather than waiting weeks for lab results.