Coal mining and biodiversity

The Fitzroy Basin Association is working in partnership with coal mining companies BHP Billiton Mitsubishi Alliance, Xstrata Coal, Anglo Coal, and Rio Tinto Coal Australia and the Queensland Resources Council to examine ways in which the industry can contribute to biodiversity gains in the Bowen Basin. Four sub-regions of the Brigalow Belt Bioregion host more than 30 coal mines and another four subregions are being explored to find more coal. The project is looking at how best to address the cumulative impacts of many coal mines over time and across the ten million hectares that make up the eight biogeographical subregions.

Our aim is to ensure the future survival of threatened species and communities that live in central Queensland's coal mining areas. Like many landholders, mining companies are very concerned about their impacts on biodiversity. Already companies contribute to endangered species recovery efforts and have sought Nature Refuge protection on some ecologically important sites. The project hopes to build on these actions across the Bowen Basin so that native biodiversity can be maintained on a regional scale.

In January 2006 the project produced a report into the statutory framework that the Queensland and Commonwealth Governments use to assess and refuse or approve coal mines and set requirements in respect of biodiversity. More recently, selected biodiversity values of the coal mining areas in the Bowen Basin have been mapped with the aim of delineating areas whose vegetation, size and condition can contribute to the long term survival of listed ecological communities and species.

A biodiversity assessment of the Bowen Basin

The Fitzroy Basin Association’s Mining and Biodiversity Project has achieved another milestone with the forthcoming publication of a biodiversity assessment of the Bowen Basin. Mapping of ecological communities and identification of highest conservation value areas is a technical contribution that together with the review of the statutory regulation of mining identifies opportunities for improving biodiversity outcomes.

The project’s review of the legislative framework for the assessment and approval of coal mining in the Bowen Basin found that [1] cumulative impacts are not addressed, and [2] the Commonwealth DEH is the principal regulator where biodiversity is involved with Queensland’s EPA taking a lesser but still significant role. When the Environment Protection and Biodiversity Conservation Act 1999 ( EPBC Act ) is triggered a bilateral agreement between the Commonwealth and State accredits environmental impact assessment by Queensland as suitable for the Commonwealth’s purposes, but inevitably approval and conditions are separate. Queensland however has jurisdiction over land tenure and so often provides the administrative avenues for Commonwealth conditions such as offsets.

Offsets involve compensation for loss of an area of valuable bushland (a listed community) by 'giving back' or protecting an equivalent or greater area of the same community. If the offset site includes regrowth capable of recovering to 'remnant' status the trade can achieve 'no net loss' of the particular biodiversity at issue.

The Commonwealth role and interests in biodiversity means that the project has focussed on those elements of biodiversity that can stop a coal mine from going ahead or require mitigation for relevant impacts on Commonwealth listed species and communities.

The biodiversity assessment of coal mining areas in the Bowen Basin is now in final edit. Some findings can be summarised …

Biodiversity planning is most appropriately done on a bioregional basis. Eight subregions of the Brigalow Belt Bioregion correspond remarkably well with the geological Bowen Basin. The Bowen Basin study area covers about 10 million hectares. Vegetation communities in this area are fairly diverse with 119 regional ecosystems identified and mapped by the Queensland Herbarium.

Some of these ecosystems are very small in extent in the area. Most are substantial in extent and most are poorly conserved in protected areas. A small number are restricted in extent and completely protected; such as 11.8.10 (kangaroo grass ( Themeda triandra ) grassland on Cainozoic igneous rocks) which only occurs on Peak Range National Park.

Strictly speaking, biological diversity includes all native biota from microbes to macropods. But we only have reasonable knowledge of higher plants and vertebrates. There are 2,900 plant species in the Bowen Basin with 33 listed as endangered or vulnerable (EV). More than fifty mammals (8 listed EV), around 400 bird species (9 listed EV), 160 reptiles (8 EV) and an at least 35 amphibians (all frogs) have their home in the Bowen Basin. Few have enough records for distribution to be comprehensively mapped.

Regional ecosystems (REs) were adopted at the best available surrogates for biodiversity. Individual occurrences of REs are mapped as polygons at 1:100,000 which is reasonably accurate AT THIS SCALE. These vegetation communities are precisely defined with soils and geology and dominant plant species and community structure (e.g. grassland, woodland or forest) used in formal descriptions.

They are so finely divided that the Commonwealth groups several Queensland defined REs on the basis of dominant floristics into three ecological communities listed under the EPBC Act : Brigalow, Bluegrass and Semi Evergreen Vine Thicket (SEVT). Brigalow communities once covered around 2 million hectares of the Bowen Basin but have now been reduced by clearing, chiefly for agriculture, to 250,000ha. The presence of any of these communities triggers the Commonwealth’s jurisdiction.

Of the 119 REs present, 39 were assessed polygon by polygon. The 39 include Brigalow (10 REs), Bluegrass (4 REs), SEVT (9 REs) and some REs endemic to the Bowen Basin or considered endangered by Queensland (EPA biodiversity status) (15REs).

The assessment sought out those patches of the selected REs considered most likely to survive into the future. The best predictor of persistence is area. Larger patches are more likely to survive than small ones. The largest ranked polygons were then checked for other biodiversity values including habitat for endangered or vulnerable species, condition where known, ecosystem diversity (many different REs in close proximity) context and connection (how much of the polygon is contiguous with intact native bush v cleared land), and whether or not the polygon falls into an EPA determined wildlife corridor. Final scores were used to identify highest conservation value areas that should be accorded high value. These areas can be targeted as ideal offset locations for the offsite mitigation of losses of the same communities to coal mining.

Predicted losses, based on 20,500ha of Brigalow REs mapped on Mining Leases and Mineral Development Licenses: are 10,000ha at full development (but could be more). Less than 1% of the Bluegrass grassland is threatened by mining. SEVT is rare and patchily distributed. Almost none is under threat from mining. Fire is the main threat to this community.

Other common or unlisted communities exist on mining company ground. They are assumed to be sufficiently abundant and not subject to threatening processes. However these communities support wildlife, often buffer threatened REs and constitute ‘biodiversity’. Miners generally take good care of this other bush growing on peripheral land despite the lack of Commonwealth interest.

Where to from here?

Consultation has commenced on solutions for biodiversity problems revealed in the values assessment and especially options appropriate for mining companies. Firstly a draft of ideas as brief dot-points is being discussed with Brisbane based environment managers, who will eliminate unworkable ideas and flesh out practical options. Secondly, a brief discussion paper will be circulated to individual mines and environment officers based on a preliminary collation of ideas agreed by the Mining and Biodiversity steering committee. When a range of practical ‘solutions’ gains support the discussion paper will be further developed in consultation with regulators to ensure that positive voluntary actions achieve real gains while (as a minimum) meet mandatory conditions.

Finally, operational aspects will be incorporated into a Biodiversity Strategy for the coal mining industry in the Bowen Basin… with a major outcome (hopefully) being simplified compliance with statutory requirements. In any case, the profile of biodiversity conservation will be raised and many practical improvements in the survival prospects of threatened communities and species achieved.