Management & Monitoring of Cave Fauna in Tasmania
In Tasmania, cave management plans and monitoring programs have recognised the significance of cave fauna, which is amongst the richest and most spectacular in the temperate zone of Australia. Conservation management of cave fauna has involved: (i) legislative protection of rare and threatened species; (ii) protection of sensitive habitats within caves by marking routes or no-go (sanctuary) areas; (iii) educating cave users, including minimum impact caving techniques. Monitoring of cave fauna has been undertaken for the purposes of: (i) gathering baseline ecological information for research, visitor management, and interpretation; (ii) measuring the ecological impacts of limestone quarrying and subsequent recovery during rehabilitation efforts.
In Kubla Khan Cave at Mole Creek, habitat degradation caused by cave visitors has been halted by installing a steel stairway. In Exit Cave at Ida Bay, certain representative or key habitat areas have been protected with string-line pathways, or else designated as no-go fauna sanctuary areas. The fauna sanctuaries include, inter alia, optimum habitat of the extremely rare blind cave beetle Goedetrechus mendumae. Although currently listed as vulnerable this species is not considered threatened by trampling. A number of Tasmanian cave species are listed as rare or vulnerable, whilst others are wholly protected. The integrity of cave ecosystems at Mole Creek is most under threat from farm development on the karst, which affects the surface vegetation, water quality, flow regimes, nutrient and sediment inputs. Public awareness of cave fauna has been addressed by producing illustrated fact sheets, which describe Tasmanian cave species, their vulnerable habitats, and minimum impact caving techniques.
The Little Trimmer Cave monitoring program was established by the Forestry Commission in 1991, to gather baseline environmental data. The biological monitoring, which has been continued by the University of Tasmania, has provided very useful life history and behavioral information on cave spiders, crickets, and amphipods. Monitoring the abundance of stream-dwelling snails, as a potential indicator of quarrying impacts, commenced in Exit Cave in 1992. This monitoring is being continued in an attempt to gauge the effectiveness of rehabilitation efforts. The same quarrying operation caused extinction of the aquatic fauna in Bradley Chesterman Cave, but recovery of the fauna occurred within five years of quarry closure, after intensive rehabilitation measures.
Monitoring of glowworms, cave crickets and cave spiders has been initiated in Exit Cave and Mystery Creek Cave to: (i) expand knowledge of the caves biological resources; (ii) to identify environmental seasons, cycles, changes and trends; (iii) to provide a baseline upon which to assess the impact of human activity in the caves. However, obtaining statistical validity may be difficult when attempting to detect human impacts to cave fauna.
Selected references
Eberhard, S.M. (1995), Impact of a limestone quarry on aquatic cave fauna at Ida Bay in Tasmania. Proceedings of the 11th Australasian Cave and Karst Management Association Conference, Tasmania, May 1995, pp. 125-135.
Eberhard, S.M. (1999), Cave fauna management and monitoring at Ida Bay, Tasmania. Tasmania Parks & Wildlife Service Nature Conservation Report No. 99/1.
Eberhard, S.M. (1999,) Reconnaissance survey of cave fauna and management issues in the Mole creek Karst National Park, Tasmania Parks & Wildlife Service Nature Conservation Report No. 99/2.