Applying knowledge of river flow–ecology links

River flows support healthy ecosystems that provide a wealth of economic, social and cultural goods and services such as fisheries, recreation and tourism attractions, bush tucker, clean water, fertile floodplains and more. Understanding the links between river flows and healthy ecosystems is therefore critical to determining how much water is needed to maintain these goods and services. In places where these links are unknown, water planners need to infer relationships from similar places until enough local field data is collected and analysed.

Environmental flows research conducted through the Northern Australia Environmental Resources Hub of the Australian Government’s National Environmental Science Program (NESP) has focused on 1) quantifying critical flow needs to sustain freshwater and coastal ecosystems, biodiversity and productivity in tropical northern Australia and 2) predicting ecological responses to flow alteration from water-resource developments. Much of this work has been conducted in the Fitzroy River (Western Australia), Daly River (Northern Territory) and rivers in Queensland’s southern Gulf of Carpentaria, and builds on previous work in these catchments. To maximise the usefulness of this research, it is important to evaluate how transferable research findings are to other locations and scales, and identify the key considerations when applying this knowledge. Understanding the inferential strength of flow–ecology links and their transferability to other locations is important for robust water planning assessment of flow-related impacts of development proposals and climate change in catchments with limited field data.

Chapter 2 of our report identifies potential constraints, opportunities and key considerations for transfer of flow-ecology knowledge. In particular, we evaluate the inferential strength of different types of ecological response relationships and issues of scope and scale. We also consider transfer and scaling of ecological responses through space and time.

Chapter 3 describes key flow-ecology principles to inform water planning and management (drawn from Douglas et al. 2019¹) and provides a synthesis of supporting evidence from NESP Northern Australia Hub environmental flow research in each focal catchment and from other studies in northern Australia.

Chapter 4 uses a case-study approach to review the quantity and quality of evidence supporting key principles relating to tropical freshwater food webs, evaluates potential transferability of aquatic food web research in northern Australia, and identifies spatial and conceptual gaps in our understanding of their ecology and management.

In Chapter 5, we synthesise ecohydrological risks associated with hydrologic alteration, river impoundment, fragmentation and other threats to ecological integrity.

Chapter 6 concludes by identifying management options to mitigate risks and enhance societal benefits of water resource development in northern Australia with a focus on strategic water resource planning and management, environmental flow management and water infrastructure management.

1. Douglas MM, Jackson S, Canham CA, Laborde S, Beesley L, Kennard MJ, Pusey BJ, Loomes R and Setterfield SA (2019) Conceptualising hydro-socio-ecological relationships to enable more integrated and inclusive water allocation planning, One Earth 1:361–373, doi:10.1016/j.oneear.2019.10.021.