Engaeus martigener (Furneaux Burrowing Crayfish)

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)

1. Scientific name, common name (where appropriate), major taxon group

Engaeus martigener (Furneaux Burrowing Crayfish)

2. International/National Context

The species is endemic to Flinders and Cape Barren Islands in Bass Strait, Tasmania.

3. How judged by TSSC in relation to the Environment Protection and Biodiversity Conservation Act 1999 criteria.

The Furneaux Burrowing Crayfish has been nominated as vulnerable, but the nominator has indicated that the species meets the criteria for endangered. The nominator, who is the acknowledged expert, indicates that on the basis of the work conducted to date this species meets the criteria for listing as endangered, however further field research would likely confirm listing the species as vulnerable, hence the nomination as vulnerable rather than endangered. However, TSSC judges the nomination to be eligible for listing as endangered under the EPBC Act. The justification against the criteria is as follows:

Criterion 1 - It has undergone, is suspected to have undergone or is likely to undergo in the immediate future a substantial reduction in numbers.

The habitat for this species is considered to be susceptible to potentially severe wildfire and subsequent habitat loss. In such an event, the potential habitat loss is likely to result in a significant decrease in numbers. Whilst the likelihood of fire has not been quantified, the nomination indicates that key habitat is identified as the most fire sensitive, there are high fuel levels, existing drought conditions, that some gully areas outside of the National Parks are subject to burning by landholders and that similar habitat on Deal Is has been completely lost due to fire and drought. The risk, within the next ten years, of fire and subsequent habitat loss and population decline can be considered high.

Therefore, the species is eligible for listing as vulnerable under this criterion.

Criterion 2 - Its geographic distribution is precarious for the survival of the species and is restricted.

The extent of occurrence is indicated to be 109km2 and area of occupancy 0.18km2. The species is known from only five sites and as indicated above, the habitat is susceptible to potentially severe wildfire with such disturbance likely to have a significant adverse impact on the species, resulting in a decrease in extent of occurrence, area of occupancy, quality of habitat and number of individuals.

Therefore, the species is eligible for listing as endangered under this criterion.

Criterion 3 - The estimated total number of mature individuals is limited and (a) evidence suggests that the number will continue to decline at a substantial rate, or (b) the number is likely to continue to decline and its geographic distribution is precarious for its survival.

The estimated number of individuals is between 22,000 and 142,000.

Therefore, the species is not eligible for listing under this criterion.

Criterion 4 - The estimated total number of mature individuals is low.

The estimated number of individuals is between 22,000 and 142,000.

Therefore, the species is not eligible for listing under this criterion.

Criterion 5 - The probability of its extinction in the wild is at least 10% in the medium-term future.

There is no quantitative evidence available against this criterion.

4. Conclusion

The Furneaux Burrowing Crayfish meets Criteria 1 and 2 for listing as vulnerable as nominated. However, the data available at this time also indicates the species is eligible for listing as endangered under Criterion 2. On the basis of the data presented it is appropriate to list this species as endangered. Should future research provide data that excludes the species from meeting the Criteria for endangered, the conservation status of the species should be reviewed at that time and amended appropriately.

5. Recommendation

TSSC recommends that the list referred to in section 178 of the EPBC Act be amended by,

including in the list in the Endangered category:

Engaeus martigener (Furneaux Burrowing Crayfish)