Sessional Committee on Environment and Sustainable Development Written Submissions Received Volume 2 Issues associated with the progressive entry into the Northern Territory of Cane Toads October 2003
Tabled Paper 1123
Tabled Papers for 9th Assembly 2001 - 2005; Tabled Papers; ParliamentNT
2003-10-16
Tabled by Delia Lawrie
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https://www.legislation.gov.au/Details/C2019C00042
https://hdl.handle.net/10070/307061
https://hdl.handle.net/10070/346011
Dr Freeland Written Submissions Cane Toad Inquiry Report Volume 2 154 from a search of the literature it was found that snake species (including frog eating specialists) on islands of the Queensland coast survived on islands with or without cane toads (Attachment 5). Although not contributing to a model of cane toad tadpole habitats under the environmental conditions of the Gulf of Carpentaria lowlands, there is a factor that may become more important in Kakadu and similar habitats. In the Gulf country cane toad tadpoles were found in habitats that averaged 2.6% (n =60) cover by macrophytes whereas the native species average was 9.9% (n = 56). There was very little macrophytic vegetation in the habitats examined in the Gulf Country whereas they are more abundant further north on the floodplain environments. Following the above research the CSIRO initiated its faunal study (Catling et al., 1999), population and pathology studies in South America, and pursued a mechanism for biological control. CSIRO responsibility is appropriate given that the cane toad is a national problem not simply a Territory problem, and that biological control using microbes is beyond the Territory's budgetary capabilities and facilities. Meanwhile the Territory began to develop and implement monitoring on parks (including regular surveys of freshwater crocodiles) and collaborated with Land Councils to develop signage to assist in preventing introduction of cane toads to off-shore islands. It was sometime in 1998-2000 when I made two related but different proposals to the Cobourg Peninsula Sanctuary and Marine Park Board. The first was for a much needed wash-down facility for all vehicles entering the Park so as to minimise the probability of introducing weeds, especially Gamba Grass. While the Board approved the concept, the issues of uncertainty about a suitable location for the facility and the Board's refusal to have Traditional Owners subject to the requirement for vehicle washdown resulted in the proposal being costed but not pursued. The second proposal was to examine the possibility of a cane toad exclusion fence across the neck of the peninsula. This would require a facility for inspection of vehicles for toads, which could not be resolved until there was resolution of the location of the weed wash-down facility (one such location would provide for happier users and efficiency). Various aspects of design (e.g. the fence, entry etc) were examined. This included the conduct of trials to determine whether cattle grids were capable of preventing cane toad access. A double grid with an appropriate system of culverts would provide for simplified vehicle access and prevent toad access, but further trials are advisable. To my knowledge the feasibility of the concept has not been examined further. Assessment of the feasibility of any such fence requires a detailed examination of possible alignments and the likely frequency of tree-fall across fences on those alignments, determination of the most suitable material for the fence (it would need to be a significant depth below ground as well as having a sun-exposed, above-ground component) and resolution of the difficult problem of what to do about the tidal parts of the fence. To minimise damage from pigs, banteng, water buffalo and possibly horses and macropods, the toad fence would need to be co-located with a fence meeting BTEC requirements (i.e. similar to the existing fence). It would also require resolution of the problem of location of the wash-down/toad search facility and the agreement of Traditional Owners to use the facility just like everyone else.