The canine olfactory system has extraordinary capabilities. Dogs possess twice as many olfactory receptors as humans and over 30 times the olfactory surface area, enabling them to detect a far wider range of odours at sensitivities estimated to be 10,000 to 100,000 times greater than those of humans. The Scent Detection Research Group at Waikato University recruits dogs from the community to participate in olfactory testing for applications in human medicine and environmental research. These capabilities create opportunities for dogs to serve as highly sensitive biological detection tools in freshwater ecosystems. We have previously demonstrated that dogs can detect invasive fish in water with sensitivities comparable to environmental DNA (eDNA) and can reliably discriminate between closely related species; koi carp and goldfish. We have recently expanded our research to evaluate the capacity of dogs to locate the highly cryptic nests of terrestrially spawning galaxiid fish. Dogs located nests more quickly and, in some cases, more reliably than human searchers, despite the challenges posed by variable atmospheric conditions and complex environmental odours in natural settings. This ability of dogs presents opportunities to undertake more rapid, frequent and extensive surveys of galaxiid spawning zones for habitat protection and enhancement.
Building on these findings, we are currently assessing the use of dogs for identifying additional invasive species, including Corbicula clams and red-eared slider turtles. Results indicate that dogs can detect clam odour both in water samples and on vehicles that have recently operated at sites with established clam populations, highlighting their potential value for biosurveillance at boat ramps or for olfactory testing of water samples alongside eDNA to confirm new incursions at the early stages of establishment. Ongoing trials are assessing the effectiveness of dogs in detecting red-eared slider nests in areas with established populations to facilitate targeted nest removal and population management.