Location of the 24 sites surveyed in 2016 (codes as shown in Tab. 1), and occurrence of live crayfish (crayfish icons), dead crayfish (crosses), sites positive and negative to crayfish plague’s eDNA (red and green circles, respectively). Main rivers surveyed are shown as blue think lines, direction of water flow is shown by black arrows and main catchment boundaries are shown by black lines. The red star indicates Killydoon location (epicentre of the original outbreak in 2015).