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Pilbara freshwater ecosystem research supported by Pilbara Corridor

Rangelands NRM, through the Pilbara Corridors Project, is funding studies looking at the function of freshwater systems in the Pilbara region in relation to the terrestrial inputs to these systems from the surrounding catchment.

The Postgraduate Research `Top-up Scholarship’ has been awarded to Jordan Iles who is a current PhD candidate at the University of Western Australia.

Mr Iles thesis, ‘Biogeochemical cycling of phosphorus and organic matter within arid freshwater ecosystem ‘s focused around sites within the Fortescue catchment.

Mr Iles said in the arid sub-tropical Pilbara region of North-West Australia, freshwater ecosystems persist under extremely variable hydrology and strong nutrient limitations, particularly of phosphorus.

Phosphorus supply is likely linked to cycles of flood and drought. However, freshwater ecosystems in the Pilbara are under increasing pressure from mining, municipal water extraction and disturbance associated with pastoral activities.

“The biogeochemical processes that underpin the ecological functioning of the streams and rivers of the northwest remain largely unknown,” Mr Iles said.

My research will investigate how phosphorus is cycled through organic matter and utilised and conserved across a range of freshwater ecosystems across the Hamersley Basin of the Pilbara.

The Pilbara region encompass a diversity of habitat types and hydrology.

A mixture of field surveys and manipulative experimental approaches in both the field and laboratory will be used to develop a mechanistic understanding of interactions between systems and the food webs they maintain.

“Whilst I am still at an early stage in my project development we have completed a catchment wide survey of the Fortescue,” Mr Iles said.

“The survey demonstrated that there is significant variation in sources and concentrations of dissolved organic matter supporting aquatic ecosystems across the catchment,” Mr Iles said.

Interactions between organic matter and phosphorus, which subsequently controls primary production within these streams, will also potentially be governed by different biogeochemical processes.

Ultimately, findings from this research will be useful for strategic planning and decision making around resource management problems in these ecosystems and may be used as benchmarks for assessing ecosystem change and restoration in the future.

The Top-up program encourages the individual to undertake their postgraduate study in an area of relevance to the Pilbara Corridors Project.

Rangelands NRM Program Manager (Pilbara) Dr Bill Cotching said Mr Iles research will provide greater understanding of inter-relationships that underpin ecosystem function in the Pilbara rangelands.

It will add value to existing and planned monitoring site data that is collected as part of the Pilbara Corridors project.

For more information, contact Jordan Iles on 08 6488 7914 or Bill Cotching on 09 9144 2800.