Informing Policy and Management in New Zealand Agricultural Regions Using Nitrogen and Oxygen Isotopes to Quantify Hot Spots and Hot Moments of Nitrate Loss

W Troy Baisden1, Clint Rissman2,3, Tim Ellis2, Sephrah Rayner4, Timothy J Clough4, Catherine Moore1, Michael Killick2, Ewen Rodway2, Travis W Horton3, Maree Clark5, Abby Matthews5 and Jon Roygard5, (1)GNS Science, National Isotope Centre, Lower Hutt, New Zealand, (2)Environment Southland, Invercargill, New Zealand, (3)University of Canterbury, Christchurch, New Zealand, (4)Lincoln University, Lincoln, New Zealand, (5)Horizons Regional Council, Palmerston North, New Zealand