CSI: Fish - using genetic testing to detect trout

We head to the Manawatu to see how the latest DNA technology, based on similar tools used by forensic scientists to catch criminals, is being used to detect spawning trout in rivers. The BioRanger device tests environmental DNA or eDNA- basically genetic traces left in the air, soil and water- and this means whole environments can be quickly and easily scanned for DNA which can then precisely identify the presence of any living species- whether that's a shark or a procreating trout. We meet Dr Adam Canning, a research scientist at Wellington Fish and Game Council, and Dr Richard Winkworth from Massey University to see how the system works.