Vanvoorstia bennettiana (Bennetts Seaweed), a marine red alga

Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee (TSSC) on a public nomination for a species listing on the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)

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

Vanvoorstia bennettiana (Bennetts Seaweed), a marine red alga.

2. National Context

The species is known to have existed at two locations only, both within Sydney Harbour, NSW.

3. How judged by TSSC in relation to the EPBC Act criteria.

TSSC judges the species to be eligible for listing as extinct under the EPBC Act. The justification against the criteria is as follows:

Criterion - no reasonable doubt that the last member of the species has died.

In 1913, a scientific paper was published indicating the species was unable to be collected despite attempts by the curator of the algal collection at the Royal Botanic Gardens, Sydney to do so. Subsequent curators have also failed to locate the species despite being active collectors.

Since 1980, it has been a State government research priority to document the entire marine algal flora of NSW. In excess of 540 dives have been undertaken without locating this species. Within Sydney Harbour, 50 dives at 12 different locations, considered suitable habitat for the species, have failed to locate the species. The dives have been conducted through each different season. During this period, university researchers, research groups and dive shop operators have been encouraged to watch for unusual specimens and briefed on the identification of this and other rare marine alga species.

The genus Vanvoorstia is characterised by similar morphology during different life cycle stages. There is no resting stage in the life cycle that could facilitate an extended period of dormancy until more favourable environmental conditions develop.

The inability of professional marine botanists to locate or collect this species from the known or other suitable localities; the significant amount of time (115 years) that has elapsed since the last collection; the extensive searching conducted during the last 20 years; and the lack of dormancy stages in the life cycle of other species in the genus, means there is minimal doubt that the last member of the species has died.

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

4. Conclusion

The inability of professional marine botanists to locate or collect this species from the known or other suitable localities; the significant amount of time (115 years) that has elapsed since the last collection; the extensive searching conducted during the last 20 years; and the lack of dormancy stages in the life cycle of other species in the genus, means there is minimal doubt that the last member of the species has died. The species is therefore eligible for listing as extinct.

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 extinct category:

Vanvoorstia bennettiana (Bennetts Seaweed)