By Australian Marine Conservation Society
Project: Mardie Salt Project
Location: Pilbara coast, Roebourne Plains & Robe River Delta Mangrove system
Impact: Loss of native vegetation in good to excellent condition, including habitat supporting the vulnerable Pilbara olive python and a Priority 3 ecological community, and significant residual impacts on the intertidal and marine values and species dependent on them.
The Mardie Project is a large-scale industrial salt and sulphate of potash project by Mardie Minerals Pty Ltd, located 80 km southwest of Karratha in the Pilbara region of WA. Spanning more than 28 km of the Pilbara coastline, the project includes seawater intakes, expansive salt ponds, bitterns disposal to the marine environment and an export facility.
The southern end of the project development envelope intersects with the Robe River Delta Mangrove Management Area. This area contains regionally significant mangroves.
The EPA’s 2021 assessment report found the proposal would have “significant residual impacts” on terrestrial flora and fauna, including clearing of critical Pilbara olive python habitat and a Priority 3 ecological community – the Horseflat Land System of the Roebourne Plains.
The EPA also assessed that the project would have significant residual impacts on intertidal and marine values from disturbance of coastal samphire, algal mat and mangrove habitats. These habitats are of high value, providing important ecosystem services that include primary productivity and nutrient cycling; foraging habitat for migratory birds; and breeding, nursery and other habitat for significant marine species.
Allowing habitat destruction to be offset in this way drives ongoing, incremental loss of biodiversity and the erosion of habitat baselines. While the research is important - and should have been conducted to inform the proposal’s assessment - as an offset project it cannot prevent or directly compensate for the certain loss of habitat. Some habitats, particularly those that provide critical habitat for threatened species, are irreplaceable and should not be offset by funding future research or management programs.
Financial offsets allow proponents to fulfil their obligations through payments, with no guarantee that actions to compensate for the environmental damage will be delivered. Moreover, there are major concerns with the Pilbara Environmental Offsets Fund itself. A 2024 review found that after six years, the program had only funded four small projects and was failing to achieve its intended outcomes.
The Australian Marine Conservation Society, Kailis and the WA Fishing Industry Council appealed the EPA’s Mardie assessment report, but, aside from some changes to conditions around transparency and oversight of the offsets, the Appeals Convenor upheld the EPA’s recommendations.
Furthermore, immediately after the approval of the project, Mardie Minerals referred an expanded project to the EPA: the ‘Optimised Mardie Project’, which was subsequently approved. The proposed expansion is significant, including a 25% increase in the Terrestrial Development Envelope, a 30% increase in clearing of vegetation in good-to-excellent condition, and a 53% increase in the discharge of bitterns.
Recommendations
- There should be no option for financial offsets through research projects.
- Ensure that all environmental offsets provide an absolute net increase in habitat and biodiversity outcomes.
- Offsets should be thoroughly monitored by an independent party with environmental credentials to ensure outcomes are met.
- Ensure that offsets are like-for-like and additional, with outcomes that are guaranteed, permanent and measurable.
- The use of offsets should be rare, and not the default.
(See also Recommendation 18 under 'Limit Use of Environmental Offsets')