Dr Betsie Milne was one of the branchiopod taxon leads that conducted the Red List assessment of South African Anostraca (fairy shrimp), an important output of the NRF FBIP Large Grant: REFRESH Project. 

REFRESH, a multi-institutional biodiversity inventory research project, was awarded a National Research Foundation (NRF) – Foundational Biodiversity Information Programme (FBIP) grant for the period 2022 to 2024, to fill urgent knowledge gaps in South Africa’s freshwater systems. Managed by NRF-SAIAB in collaboration with the South African National Biodiversity Institute (SANBI), taxon experts aimed to update and generate comprehensive data on species diversity and distribution of freshwater branchiopods, crabs, dragonflies, fish, fish parasites, frogs and molluscs, to assess changes in their species distributions and ultimately inform freshwater management and decision-making.

Anostraca red listing  

Branchiopods play a crucial role in the ecosystem function of temporary freshwater habitats. As filter feeders, they control algae and bacteria, and they are an important food source to macroinvertebrate nymphs and larvae, as well as migratory waterbirds. The southern African branchiopod fauna is rich, with 64 currently described species in the orders Notostraca (tadpole shrimp), Anostraca (fairy shrimp), Laevicaudata and Spinicaudata (clam shrimp).

Compared with the other large branchiopod orders, Anostraca is the most diverse, and more sensitive to specific habitat conditions. This makes them good candidates for indicating change in the continuously threatened temporary aquatic ecosystems they inhabit. Moreover, they are taxonomically much better defined, while the systematics of tadpole shrimp and clam shrimp are complex.

They were therefore selected as the focus group for the red listing process. Until recently, only 8% (30 species) of global Anostraca species appeared on the IUCN Red List, of which four were from South Africa. Many South African species did not meet the criteria to be evaluated during the last national attempt in 1996.

However, considerable advances have been made in anostracan research in South Africa over the past 30 years, and 36 species were evaluated in the recent assessment. Of these, 23 species are widespread and abundant, which means that 64% of South African anostracan species are not currently at risk of extinction. The remaining 13 species are of conservation concern, of which nine species are threatened with a high risk of extinction.

The key threats that these species are facing, include habitat loss through urban development, agriculture and mining. Sadly, the branchiopods and their unique temporary freshwater habitats are not currently being actively protected. Although 46% of the species of conservation concern occur in protected areas, these protected areas are primarily mandated to protect something else and no specific conservation measures are in place for the Anostraca.

A deception of protected areas for species conservation is well illustrated in the case of the critically endangered Rhinobranchipus martensi, which was discovered, and last collected, in 1989 in the Thomas Baines Nature Reserve in the Eastern Cape. A well-intentioned conservation action to attract birds to the reserve turned the temporary pool into a permanent waterbody, which have now resulted in the possible extinction of Rhinobranchipus martensi.

This recent Red List assessment hopes to strengthen the fight against current threats that Anostraca are facing and assist attempts for better protection of this taxon and its habitats. Results of the assessment were published on the IUCN website in October (version 2025-2) and threatened Anostraca will be included in the Environmental Screening Tool of the Department of Forestry, Fisheries and the Environment (DFFE), which will be updated early 2026.  

Betsie worked closely with the late Musa Mlambo and Daksha Bills from the Albany Museum, as well as Dr Dewidine Van der Colff and Keenan Meissenenheimer from SANBI to compile the assessments, while long-standing experts Prof Jenny Day and Prof Michelle Hamer acted as reviewers.

A Parisian summer congress  

The Crustacean Society (TCS) held their annual congress in Paris, France, in July this year. The congress, hosted by researchers from Sorbonne University and the French National Museum of Natural History, was attended by some 250 delegates from 40 countries. Presentations on research conducted on marine and freshwater crustaceans throughout the world ran over four parallel sessions.

Betsie presented the key findings from the red listing of South African Anostraca during the symposium on Temporary and Hypersaline Habitats, on behalf of her REFRESH Branchiopod team. Throughout the congress, she was able to network with international collaborators and peers, gaining insight into current international research foci and trends in branchiopod research. She also visited the branchiopod collection hosted by the French National Museum of Natural History, courtesy of Professor Nicolas Rabet.

Betsie is immensely grateful to NRF-SAEON for their generous support in funding her attendance.