Stellenbosch University (SU) shark geneticists are elated about the news that South Africa will vote in favour of providing greater protection through CITES to thresher sharks, silky sharks and nine mobula ray species

"As concerned members of the academic and shark scientific community, we would like to express our support for inclusion of the thresher shark, silky shark and nine species of mobula ray proposed listings for CITES Appendix II," says Dr Aletta Bester-van der Merwe of the SU Department of Genetics, and Katie Gledhill, a SU research affiliate and PhD student at the University of Technology Sydney. "Inclusion of these species listed on CITES Appendix II will help to ensure that any international trade in these species will be managed sustainably and will be of little detriment to wild populations."

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) convention of the parties (otherwise known as CoP17) is currently being held in Johannesburg, South Africa. CITES is widely recognised as an effective tool to reduce global trade in endangered species.

"The stance taken by South Africa shows that the country is serious about shark conservation and the sustainable management of shark fisheries and trade," says Gledhill, who works as a research scientist for the South African Shark Conservancy. "Getting these species listed on CITES Appendix II will ensure that any international trade in these species will be managed sustainably and will be of no detriment to wild populations."

"This will ensure that future generations will have sustainable shark populations for years to come," she adds.

She added that South Africa has been at the global forefront of shark conservation efforts, including the first country to give white sharks national protection.

"As hosts of the CITES CoP17 event, we would like to see African nations take a united front and vote for inclusion of the proposed listings for sharks and rays on CITES Appendix II," says Gledhill.

Silky and thresher sharks are found in South African waters, but are not species of economic importance to the local fishing industry. Thresher sharks are tourism attractions around smaller island nations such as the Philippines.

According to Gledhill there has been a worrying increase in the trade of gill plates of mobula ray species for use in traditional Chinese medicine.   

Pre-CITES discussions

Gledhill was one of the invited speakers at a pre-CITES CoP17 shark conservation workshop in Cape Town in mid-September hosted by the South African Department of Agriculture, Forestry and Fisheries (DAFF). The workshop was attended by delegates from throughout Southern Africa and the West Indian Ocean region, including South Africa, Mozambique, Seychelles, Maldives and Sri Lanka. Government representatives, fisheries managers, non-government conservation organisations, shark eco-tourism operators and the scientific community attended the event.

Gledhill presented information about the unique biodiversity of Southern African sharks and rays, including aspects of her postgraduate research.

"Sharks have important roles in marine ecosystems and a growing high ecotourism value in South Africa," she says.

History of the shark and ray listings

In 2015, Sri Lanka, the Maldives and Fiji submitted proposals to list silky sharks, three species of thresher sharks and nine mobula ray species on CITES Appendix II. The proposals were put forth in response to scientific evidence of global declines in these species; between 70-99% in some areas.

More than 50 countries have agreed to co-sponsor listing one or more of these shark and rays species, including several African nations.

Research on the genetics of sharks

As part of her PhD work, Gledhill is investigating the population genetics of South Africa's endemic catsharks, and assisting marine scientists to distinguish species based on molecular and taxonomic data.

Her work is supervised by Dr Aletta Bester-van der Merwe of the Molecular Breeding and Biodiversity Group of Stellenbosch University's Department of Genetics. The Group has several ongoing shark genetics projects. Work is among others being done on various exploited shark species including for example the CITES-listed smooth hammerhead shark.

"Our current research at Stellenbosch University on shark species demonstrates the connectivity of shark populations in different regions and highlights the need for a trans-national approach to the conservation and management of threatened shark and ray species," says Bester-Van der Merwe.

• Read here about a recent research project on the population genetics of soupfin or tope sharks, copper or bronze whaler shark and the endemic lesser sandshark found in South African waters.

Caption: A thresher shark, as photographed by Shawn Heinrichs.

For media enquiries

Katie Gledhill
Research affiliate student at Stellenbosch University and a PhD student at the University of Technology Sydney
Research Scientist at the South African Shark Conservancy
katie@sharkconservancy.org
+27 72 143 2599

Dr Aletta Bester Van der Merwe
Department of Genetics
Stellenbosch University
aeb@sun.ac.za
+27 21 808 5835