What about the risk of false positives e.g. from a Heron eating a GCN and pooping in the pond or ducks moving between ponds and carrying DNA from one to the other?
eDNA technology is very sensitive and theoretically there is potential for this type of environmental contamination. However, we would expect that this is very rare. When clients have speculated to us that they believe this may explain a surprising positive result, subsequent surveys have usually confirmed GCN presence.
