Understanding the distribution and diversity of organisms within a region is fundamental for environmental managers tasked with developing and implementing effective strategies to protect biodiversity. Over ~10 years, Melbourne Water contributed to research developing and testing eDNA techniques suitable for assessing aquatic vertebrate biodiversity at a landscape scale.
In 2021, a project was implemented that covered ~70 subcatchments. 1863 unique sites were sampled over 24 months (sites sampled multiple times; Spring and Autumn only) in wetland, estuarine and stream habitats, with the total number of samples nearly 8000. The program was specifically designed to baseline fish, frog and platypus diversity and/or range for monitoring long term biodiversity change.
The logistics of running such a large-scale project in compressed timelines necessitated uplift in several key areas; 1) staffing capacity to ensure necessary sampling intensity was achieved 2) sample throughput 3) Project Management effort 4) expectation management.
The program delivered a comprehensive baseline of aquatic vertebrate biodiversity for the region. 332 taxa were detected in total including ~114 target taxa (e.g. aquatic dependent vertebrates; 103 fish taxa, 10 frog taxa and Platypus) and 218 off target taxa. Birds (132 taxa) and mammals (65 taxa) comprised the majority of off target taxa.
The generated dataset holds promise for extensive analysis relating predictor variables like landuse, hydrologic modification, landscape connectivity and climate change to species distribution. The dataset is already proving a valuable compliment to traditional sampling methods. A remaining challenge is how to best incorporate expanded knowledge into business processes and reporting requirements.
Author and contributor information:
This project was a close collaboration between Melbourne Water and Enviro DNA.
Al Danger, Rhys Coleman and Ryan Burrows are waterway managers at Melbourne Water, responsible for developing and delivering ecological monitoring programs that assess the performance of investment programs like revegetation, stormwater reduction and habitat reconnection. Andrew Weeks, Reid Tingley and Sarah Hale at Enviro DNA developed and implemented eDNA sampling, processing and data analytic techniques that facilitated the delivery of the program.