A critical question for Melbourne Water is understanding the extent and diversity of wildlife in our waterways. This information is used to inform management priorities.
Traditional approaches to monitoring biodiversity in waterways are labour-intensive. Many hours are spent sampling in the field, or counting freshwater invertebrates in the laboratory. Techniques such as netting and electrofishing involve some inherent safety challenges, can be invasive, time consuming, and can underestimate species that are rare or patchily distributed.
To address some of these limitations, Melbourne Water’s Applied Research team is involved in an innovative project utilising new technology known as environmental DNA, or eDNA. eDNA is a revolutionary sampling and monitoring technique that offers a safer and more efficient alternative for wildlife and field staff.
In this process, water samples are collected from multiple locations along streams, rivers, or wetlands. These are then processed in the laboratory to extract the DNA of the target species that has been left in the water (e.g. hair, scales, mucous, skin). The DNA is examined using a process known as polymerase chain reaction, in turn providing data on invasive, endemic and threatened species in freshwater environments.
Recently, eDNA has been used to monitor a diverse range of aquatic animals, including platypus, fish, frogs, birds and invertebrates at over 300 sites across Melbourne.
At a cost of around $50 a sample, eDNA is a significant addition to traditional monitoring methods and will improve Melbourne Water’s biodiversity data and related management decisions.
Our research partner, the Centre for Environmental Stress and Adaptation Research, is currently investigating the use of eDNA to do multi-species biodiversity assessments. This is expected to be substantially more cost effective and sensitive, and provide managers, government agencies and the industry with real-time measures of a broad range of biodiversity.