Waterway managers invest significant resources in protecting and restoring biodiversity of aquatic ecosystems. However, quantifying spatial and temporal changes in biodiversity is challenging and hampers our understanding of the effectiveness of management actions or the impact of anthropogenic disturbances. Traditionally, indirect measures are used to infer “aquatic health” (e.g. water quality metrics) or biotic metrics are limited to a particular taxonomic group as an indicator for the entire ecosystem (e.g. fish, macroinvertebrates). Although valuable, these metrics may have limited scope, lack sensitivity and/or not provide a true indication of overall biodiversity of the system.
The Resilient Rivers eDNA Project uses environmental DNA metabarcoding to investigate aquatic biodiversity across multiple seasons at ~250 sites throughout 11 catchments in southeast Queensland, incorporating a broad range of habitats and land uses. Using multiple complementary assays, eDNA metabarcoding allows us to investigate biodiversity at multiple levels including micro-organisms (e.g. bacteria, fungi, algae, diatoms), macroinvertebrates, and macro-organisms (e.g. vertebrates, plants) as well as undertake surveys at large spatial scales. This includes taxonomic groups that are likely to be highly sensitive to disturbance and respond quickly to rehabilitation efforts. Critically, the survey design overlaps with long term environmental monitoring across the region (Ecosystem Health Monitoring Program by Healthy Land & Water) allowing us to investigate relationships between biodiversity and environmental variables with the potential to develop new aquatic biodiversity metrics that may provide more holistic and sensitive assessment of waterway health. Preliminary data is presented here with strong correlation between eDNA data and existing biotic indices.