Because of its sensitivity, eDNA can be a complementary tool for confirming species eradication success. eDNA surveys were conducted in Lake Sorell, Tasmania (IFS 2016), where an extremely low-density population of European carp, Cyprinus carpio, is present. The results were used to determine the survey effort required to confidently detect carp at their current density as well as the increased survey effort required to detect carp when their population drops to just several or a single individual.