This project aimed to determine environmental water requirements of key plants and animals for the Fitzroy River in the Kimberley region of Western Australia.
An initial conceptual model was developed (from literature reviews) to describe hydro-socio-ecological relationships to encourage more integrated and inclusive water allocation planning. This included 10 key considerations for water planning which fed into the development of initial water-planning documents by the Western Australian Government.
The ecological relationships in this conceptual model were largely based on evidence from elsewhere in northern Australia (and even further afield), as there was very little data on the relationships between flow and biota or habitats for the Fitzroy itself. This helped to identify key ecological knowledge gaps for the Fitzroy River. These knowledge gaps guided research design and data collection for on-ground studies focusing on freshwater biota (algae, fish, cherabin) and riparian vegetation in the Fitzroy, conducted in partnership with Traditional Owners and Indigenous rangers.
This new research details five flow-biota relationships and 14 habitat-biota relationships, including studies on algal biomass, fork-tailed catfish, cherabin and riparian vegetation. Flow-biota relationships are particularly useful for environmental water planning because they provide a direct link between river flow and an ecological outcome – such as cherabin population size and catfish body condition – indicating potential implications of water extraction.
The initial conceptual model was updated and refined with new ecological evidence that emerged during the project, resulting in a model that is populated largely by knowledge generated from research undertaken in the Fitzroy instead of elsewhere. This model is more defendable and provides stronger evidence for water planning, but with less ecological breadth than the initial version.
We recommend that both models be used to guide management decision-making and policy development for the river.
The Fitzroy River in the Kimberley region of Western Australia.
The initial hydro-socio-ecological conceptual model of the impacts of water abstraction in the Fitzroy River. The model is centred on four flow phases and the potential impacts of abstraction during each flow phase. Small inner circles describe impacts on hydrology and physical habitats, large outer circles describe impacts on habitat availability and quality, and water-dependent biota and ecological processes. Impacts of particular interest to Indigenous people are in bold type. The quotes illustrate Indigenous perspectives on hydro-socio-ecological relationships. The outer circle encompasses the key social factors and conditions that affect water allocation planning. Taken from Douglas et al. (2019).
The revised conceptual model using only research undertaken in the Fitzroy River. Black text = NESP evidence, published; black text italicised = NESP evidence, unpublished. Grey text = non-NESP evidence, published.
A representation of the zonation of riparian woody plants, including photographs representative of each zone.
This project generated new ecological evidence to support water planning in the Fitzroy River, increasing our knowledge of riparian vegetation, fish and cherabin, the aquatic food web, the water chemistry of pools and hydrological connectivity. The most direct flow-biota relationship generated by this project is the link between the duration of floodplain inundation and the probability of occurrence of different riparian tree species. The relevance of this research to water policy decision-making was maximised by using this flow-biota relationship to predict tree occupancy for the different water-take scenarios that were used in a discussion paper by state government water managers. Spatial mapping across the lower Fitzroy River highlighted areas most vulnerable to water extraction. The species most vulnerable to wet-season water harvesting are Melaleuca argentea (silver-leaved paperbark), M. leucadendra (weeping paperbark), Nauclea orientalis (Leichhardt tree) and Barringtonia acutangula (freshwater mangrove), which may make them good candidates for monitoring to assess environmental impacts.
Other flow-biota relationships generated by this project can also inform and support water management decisions. For instance, the positive link between years with high wet-season flows and the energy stores of fork-tailed catfish in dry-season pools reinforces the importance of flow/water availability as a critical force shaping the ecology of riverine biota. Protecting wet-season flows during years with low river discharge will be particularly important for fork-tailed catfish so that they can accumulate the energy stores needed to survive during the subsequent dry season.
Habitat-biota relationships are also useful for water planning because they can reveal the changes likely to arise if the availability and quality of habitats change due to water extraction. For instance, knowledge generated by this project about the importance of the floodplain for fish recruitment and growth indicates the importance of protecting within-bank flows that fill flood-runner channels and replenish flood-runner pools. Similarly, flood flows are important for maintaining wetlands in the floodplain, which are important habitats for the recruitment of riparian plant species.
Researchers Leah Beesley, Chris Keogh and PhD student Thiaggo de Castro Tayer sampling fish and algae in collaboration with Yimardoo-Warra Rangers Jeremiah Green and Shaquille Millindee. Photo: Michael Douglas.
Although it wasn’t a key objective of the research, our research findings highlight the need for an effective monitoring program to protect the ecological assets of the Fitzroy River and support water allocation decisions. A monitoring program must:
For monitoring to successfully assess the impacts of water extraction, a baseline dataset must be amassed that accurately describes natural range of conditions experienced by plants and animals. The data set collected by this project helps to identify critical features to monitor, but it is relatively short-term and is insufficient as a baseline dataset.
This project has markedly increased the ecological knowledge related to flow and riverine habitats in the Fitzroy River. It has also identified key knowledge gaps that should be the target of further research, including:
Canham, C. A., Beesley, L. S., Gwinnn, D. C., Douglas, M. M., Setterfield, S. A., Freestone, F. L., Pusey, B. J., & Loomes, R. C. (2021). Predicting the occurrence of riparian woody species to inform environmental water policies in an Australian tropical river. Freshw Biol., 00, 1– 13. https://doi.org/10.1111/fwb.13829
The Northern Australia Environmental Resources Hub addressed key research questions to come up with practical, on-ground solutions to some of the north’s most complex environmental challenges. A transdisciplinary research approach has been at the heart of the hub. Integrating key research users – policy-makers and land managers including Traditional Owners and ranger groups – into the co-design of research projects has led to rapid uptake of research outcomes into land management practices and decision-making. The hub has produced this wrap-up video outlining these impacts from the perspectives of research users.
Canham, C.A., Duvert, C., Beesley, L.S., Douglas, M.M., Setterfield, S.A., Freestone, F.L., Clohessy, S. and Loomes, R.C. (2021), The use of regional and alluvial groundwater by riparian trees in the wet‐dry tropics of northern Australia.. Hydrological Processes. Accepted Author Manuscript. https://doi.org/10.1002/hyp.14180
Beesley, LS, Pusey, BJ, Douglas, MM, Keogh, CS, Kennard, MJ, Canham, CA, Close, PG, Dobbs, RJ, & Setterfield SA. When and where are catfish fat fish? Hydro‐ecological determinants of energy reserves in the fork‐tailed catfish, Neoarius graeffei, in an intermittent tropical river. Freshwater Biology. 2021; 00: 1– 14. https://doi.org/10.1111/fwb.13711
Beesley, L.S., Pusey, B.J., Douglas, M.M. et al. New insights into the food web of an Australian tropical river to inform water resource management. Sci Rep 10, 14294 (2020). https://doi.org/10.1038/s41598-020-71331-0
Burrows, R.M., Beesley, L., Douglas, M.M. et al. 2020. Water velocity and groundwater upwelling influence benthic algal biomass in a sandy tropical river: implications for water-resource development. Hydrobiologia doi:10.1007/s10750-020-04176-3
Douglas, M.M., Jackson, S., Canham, C.A., Laborde, S., Beesley, L., Kennard, M.J., Pusey, B.J., Loomes, R. & Setterfield, S.A. (2019). Conceptualizing Hydro-socio-ecological Relationships to Enable More Integrated and Inclusive Water Allocation Planning, One Earth, Volume 1, Issue 3, 361-373, ISSN 2590-3322. https://doi.org/10.1016/j.oneear.2019.10.021.
David Crook discusses how otolith chemistry can help explain and document fish life history.
The project was led by Professor Michael Douglas from The University of Western Australia (UWA). Professor Douglas was assisted by researchers from UWA, Charles Darwin University, Griffith University and the Western Australia Department of Water and Environmental Regulation.
Gooniyandi Aboriginal Corporation PBC, Walalakoo Aboriginal Corporation PBC, Wilinggin Aboriginal Corporation and Yi-Martuwarra/Yanunijarra Aboriginal Corporation PBC were collaborators in this research.
This project was completed in June 2021.
Professor Michael Douglas, UWA