23 – The technology revolution: improving species detection and monitoring^309leading to detection of non-viable populations. Perhaps a more serious problem is
the potential for sample contamination – both in the field and in the laboratory.
Clearly, strict protocols must be developed and meticulously adhered to. Other
sources of contamination, such as the transfer of a threatened species’ eDNA to an
unoccupied site by a non-target species, will be much more difficult to control.
Uptake by conservation agencies will (and should) also depend on the extent to
which eDNA sampling outperforms traditional monitoring methods – both in
terms of sensitivity and cost-efficiency. Fortunately, dozens of papers have made
such comparisons in recent years, and these have been undertaken in a wide range
of aquatic environments, and for a vast array of taxa. Many of these studies have
shown that eDNA sampling achieves higher detection rates than traditional
sampling methods. One such study by Smart et al. (2015) used mitochondrial
primers and quantitative PCR to demonstrate that eDNA sampling was
substantially more efficient than a traditional trapping technique for detecting
non-native newts Lissotriton vulgaris at seven field sites in suburban Melbourne.
They subsequently showed that eDNA sampling can also be more cost-efficient
than trapping when primer/probe development and sample processing costs are
low (Smart et al. 2016). Finally, as has been emphasised in many chapters of this
book, the decision as to whether adopt eDNA sampling, in lieu of more established
traditional survey methods, will depend crucially on the monitoring program’s
objective. For example, eDNA sampling may be useful for characterising the extent
of range contraction of a threatened species, but lack sufficient resolution to
determine the effectiveness of different management interventions for increasing
the population size of a threatened species. Although several eDNA studies suggest
that eDNA concentrations are positively correlated with organismal abundance,
the strength of that relationship is often highly uncertain and is likely to be
species- and habitat-specific. In addition, differentiating among management
interventions may require more detailed data (e.g. sex and age ratios, disease status,
genetic variation) than can currently be gleaned from eDNA data (but see
Sigsgaard et al. 2016).
Discussion
Many technological advances are becoming increasingly affordable, creating
opportunities to use cutting-edge technology to improve biodiversity data
collection, including threatened species monitoring. New technologies could truly
revolutionise the way we collect data on threatened species and habitats, and
provide new tools to support conservation action. However, we must be wary of
claims that new gadgets or techniques will solve our data collection problems. We
invite the reader to google ‘hype curve’ for a graphic depiction of how new
technologies typically generate a lot of expectations in their early stages, which are