Background/Aims:
The Pilbara region of Western Australia is renowned for its rugged, ancient landscapes and harsh climate. Many river systems are intermittent, with seasonal flows following cyclonic rainfall events, but permanent pools and springs also exist where groundwater intersects the surface or gorges limit evaporation. These unique and isolated aquatic habitats support at least 15 freshwater fish species, of which a high proportion are endemic to the region. Against this backdrop sits a booming iron ore industry. In the 2023-2024 financial year, the Pilbara’s iron ore output was 885 million tonnes, and new major iron ore mines are planned to be developed every year to 2030. Under the State’s environmental impact assessment (EIA) framework, proponents are required to assess the potential impacts of proposed mines or mine expansions, backed by evidence from ecological surveys. Technical guidance for sampling terrestrial vertebrate and invertebrate fauna, flora and subterranean fauna is provided by the Western Australian Environmental Protection Authority, however, no specific guidance exists for freshwater fish.
Methods:
In this presentation, we review the current ‘state of play’ for freshwater fish sampling for EIA in the Pilbara, in the absence of prescriptive technical guidance. This will include a description of the best practice methods used by all major aquatic ecology consultants, as well as new and innovative techniques currently being trialed.
Results:
The types of data produced by consultants will be discussed, and how these results are applied in EIA. Several case studies will be examined to show how consultant survey results have enhanced the knowledge of the Pilbara’s fish fauna, and how they assist in targeting areas required for further and more specific research. In some cases, consultant surveys have the benefit of providing long-term (10+ year) datasets that provide valuable information on fish population dynamics in river systems affected by iron ore mining.
Conclusions:
We will conclude by discussing some of the challenges faced as consulting ecologists employed by the mining industry, and open the conversation about what is needed to drive improvement in the sector to ensure protection of the Pilbara’s unique freshwater fish.