Threatened Species and threatened ecological communities
Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee (TSSC) on Amendments to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)
Clarissa tasbates (Flightless Sawfly)
Clarissa tasbates (Flightless Sawfly) has only been found within 500 m of Pelion Hut, 860 m above sea level, at a site 3 km south of Mt Oakleigh, western Tasmania. It is found within the Cradle Mountain-Lake St Clair National Park, which is part of the Tasmanian World Heritage Area. The species was discovered in 1996, and nothing is known about the size or variability of the population.
The Flightless Sawfly is not listed under the EPBC Act, nor is it listed as threatened under Tasmanian legislation.
TSSC judges the species not to be eligible for listing under the EPBC Act. The justification against the criteria is as follows:
There is no quantitative data available against this criterion. Therefore, the species is not eligible for listing under this criterion.
The Flightless Sawfly has been found at several sites within 500 m of each other in Cradle Mountain-Lake St Clair National Park, which is part of the Tasmanian World Heritage Area. Although there have been some surveys of other suitable habitat, there is much suitable habitat in upland Tasmania that has not been surveyed for this species. If the Flightless Sawfly is restricted to the one locality, then it is estimated that the extent of occurrence is 0.02-0.04 km2.
However, despite its possibly limited geographic distribution, current knowledge indicates that the Flightless Sawfly is secure where it has been found within the Cradle Mountain-Lake St Clair National Park. There is no evidence that the species has undergone any change in range in the past, and none is predicted in the future. The only known threats to the species are possible human impacts resulting from management of hiking tracks and huts as the location is close to such facilities. But according to the draft Action Plan for Non-Marine Invertebrates, currently such impacts do not appear to be threatening the population. There is also the possibility of random catastrophic events which can have great impacts on a population with a very restricted distribution.
The Flightless Sawfly may have a restricted distribution, but in the location where it has found, it can be considered to be secure as no specific threats have been identified. Therefore, the species is not eligible for listing under this criterion.
There is no quantitative data available against this criterion. Therefore, the species is not eligible for listing under this criterion.
There is no quantitative data available against this criterion. Therefore, the species is not eligible for listing under this criterion.
There is no quantitative data available against this criterion. Therefore, the species is not eligible for listing under this criterion.
The Flightless Sawfly is known currently from one location, indicating it may have a restricted distribution, but more surveys of suitable habitat are needed before the actual distribution is known. Currently, the species is found entirely within a wilderness area of a national park, has no identified threats and can therefore be considered secure. There is no reason to suspect that the species has undergone any change in range in the past, and none is predicted in the future. The only known threats to the species at the location where it has been found are possible human impacts resulting from management of hiking tracks and huts as the location is close to such facilities. According to the draft Action Plan for Non-Marine Invertebrates, such impacts do not appear to be threatening the population.
The species is not eligible for listing under the EPBC Act.
TSSC recommends that the species Clarissa tasbates (Flightless Sawfly) is not eligible for inclusion in the list referred to in section 178 of the EPBC Act.
Clarke, G.M. & F. Spier-Ashcroft. 2001. The Action Plan for Australian Non-Marine Invertebrates - Draft Sept. 2001. Env. Aust., Canberra.