Clearing and degradation due to sugar cane farming
Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee on a public nomination of a Key Threatening Process Environment Protection and Biodiversity Conservation Act 1999
1. Name and description of the key threatening process
'Clearing and degradation of lowland forest, feather palm swamps, freshwater wetlands, grassland ecosystems, littoral rainforest and other ecosystems, along the eastern seaboard (coastal lowlands) bioregions of Queensland due to sugar cane farming and expansion'.
This nomination examines past and predicted losses to sugar cane production of riparian habitats, littoral rainforest and other ecosystems along the eastern seaboard of Queensland. The nominator recognises that other land uses will have also encroached and degraded habitat for threatened and other species but maintains that references cited in the nomination attribute sugar cane expansion to be the major cause.
The nomination asserts that the amount of land under sugar cane production has expanded at a rapid rate in recent years utilising increasingly marginal land, including habitats of high conservation value. The nominator believes this rate of expansion will continue. The nomination addresses the 'inadequacy and ineffectiveness' of current environmental controls and guidelines governing cane expansion. The nomination also covers the issue of habitat degradation caused by the process of cane growing, and includes issues such as soil erosion, stream sedimentation, diffuse source pollution, acid sulphate soil pollution and the use of rodenticide which are spreading with the expansion of cane farming.
Cane expansion occurs between the Great Barrier Reef and the Wet Tropics, and the nominator believes it is impacting on the values of both these World Heritage areas.
2. How judged by TSSC in relation to the Environment Protection and Biodiversity Conservation Act 1999 criteria
- Could the threatening process cause a native species or an ecological community to become eligible for listing as Extinct, Extinct in the Wild, Critically Endangered, Endangered or Vulnerable?
- Could the threatening process cause a native species or an ecological community to become eligible to be listed in another category representing a higher degree of endangerment?
- Does the threatening process adversely affect 2 or more listed threatened species (other than conservation dependent species) or 2 or more listed threatened ecological communities?
Thirty unlisted species and twenty nine unlisted communities are included in the nomination as likely to become listed due to this process. The nomination notes that for some species it may be regional populations at threat.
The threatened species listed in the nomination as being threatened by the process are:
- Mahogany glider Petaurus gracilis (Endangered)
- Southern Cassowary Casuarius casuarius johnsonii (Endangered)
- Proserpine Rock Wallaby Petrogale persephone (Endangered)
- Mary River Tortoise Elusor macrurus Endangered
- Mary River Cod Maccullochella peelii mariensis (Endangered)
- False Water Rat (Xeromys myoides) (Vulnerable)
For the majority of species and communities the threat described relates to clearing and fragmentation of habitat. There is little information on the nature or degree of threat due to sugar cane growing. Expert opinion indicates there is little evidence directly linking sugar cane growing and expansion to any threat on these species, except in the case of owls. There is reasonable evidence of the secondary poisoning of owls from the rodenticide Klerat. Expert advice indicates this rodenticide is no longer used in cane growing.
The nomination recognises that the sugar cane industry in Queensland is already regulated, with mechanisms controlling the number of cane growers, the areas of cane planted, the location of planting and the quantity of sugar produced. The nomination also recognises that the greatest limitation with environment controls on cane assignment is the stage at which it occurs in the development process. Cane assignment is often for land that has already been purchased and cleared and just determines whether cane can be cultivated on it.
Land clearance in the coastal lowlands of Queensland occurs for a range of purposes, including sugar cane growing, urban expansion, fruit plantations, and grazing activities. Expert opinion on the nomination indicates that clearing in this region is not sugarcane-specific (ie. it is difficult to define clearing of land for sugar cane as a threat, since the land utilised by cane growers is usually already cleared). Therefore, further restrictions on cane assignment will not necessarily prevent land being cleared for other purposes, and the complete elimination of the cane industry would not remove the threat of clearance.
Based on expert opinion regarding the measures utilised by the industry to mitigate landscape degradation, the lack of evidence of sugarcane farming as a threat, and the recognised non-specific nature of land clearing with regard to the sugar cane industry, the TSSC considers that the threatening process:
- is not likely to cause a native species or an ecological community to become eligible for listing in any category, other than conservation dependant;
- is not likely to cause a listed threatened species or a listed threatened ecological community to become eligible to be listed in another category representing a higher degree of endangerment; and
- does not adversely affect 2 or more listed threatened species (other than conservation dependant) or 2 or more listed threatened ecological communities.
The threatening process does not meet s188(4)(a), s188(4)(b), or s188(4)(c) of the EPBC Act.
While recognising the broader issue of land clearing as a threatening process, TSSC recommend that Clearing and degradation of lowland forest, feather palm swamps, freshwater wetlands, grassland ecosystems, littoral rainforest and other ecosystems, along the eastern seaboard (coastal lowlands) bioregions of Queensland due to sugar cane farming and expansion is not eligible for listing as a Key Threatening Process under the EPBC Act.