By Dr Jennifer Pierson, Senior Ecologist
It is almost like magic, getting to look inside the cells of a critter and seeing the DNA that contains the instructions for life. Patterns in DNA tell the story of an organism’s history, patterns of relatedness within and among populations, as well as how it moves around the landscape. All of this from a tiny two millimetre tissue sample, a few drops of blood, or even a few hair follicles.
One of the incredible things about the work that Australian Wildlife Conservancy (AWC) does in remote regions across Australia is the ability to collect different types of genetic samples from animals, contributing to new knowledge and better conservation decision-making. As AWC and our work grows, so has our collection of tissues from the diverse wildlife we monitor, leading to a collection of almost 10,000 tissue samples as well as scat, hair, and sometimes even whole specimens, stored at properties across the country. While samples are stored in ethanol to protect the DNA inside from breaking down, long-term protection of this precious resource requires proper curation – that means quality freezers that do not thaw out and refreeze (which damages the DNA), proper labelling, organisation and recordkeeping. Needless to say, a big job.
This collection is used across several of our programs. For example, in the Kimberley, we have been working towards confidently identifying Northern Brown Bandicoots (Isoodon macrourus) and Golden Bandicoots (Isoodon auratus) in the hand so we can track the distribution, occupancy, and abundance of these species in the region. For the last few years, we have been working with the Australian Museum to provide a species identification based on tissue samples collected from each individual caught. After collating years of data, field ecologists have found there are indeed some morphological differences in body size between the two species that will allow our teams to distinguish these populations. Regular monitoring in the Kimberley provides the opportunity to collect tissue from poorly understood species, highlighting important cryptic diversity that needs conservation.
Future proofing our deposits
As AWC moves into metapopulation management of several species in our translocation program, we can conduct genetic studies at the national scale, with one sample providing management direction for several sanctuaries or partnership sites at once. The Numbat (Myrmecobius fasciatus) samples collected in translocation programs for Mt Gibson and Mallee Cliffs are providing both a baseline assessment of the genetic health of the founding populations in these new populations, as well as a health check of the Scotia population where some of the founders were sourced. The coordination of analyses across properties, sometimes on both AWC and partner properties, provides a more informative overview of how the populations are faring – but also requires years to build the sample collection for evaluation. Improper storage can lead to samples failing when it comes time to sequence them due to the degradation of the DNA. Given the scarcity of access to tissue for these rarely-handled species, the cost of proper storage is a wise conservation investment.
The next phase of managing AWC’s tissue collection is establishing a centrally-managed National Tissue Storage Collection. The recent floods at Mornington highlight the vulnerability of these irreplaceable samples being stored in remote field locations. At any time, electricity failures – even for a short time – can cause damaging cycles that may reduce the quality of the sample long-term. By moving the samples to a central location, we will be able to ensure high-quality storage and curation of the samples and facilitate the use of samples by the wider conservation and research community.
Read and download the full issue of Wildlife Matters here.