Page 57 - University of Pretoria RESEARCH REVIEW 2018

Conservation genetics –
in search of marine evolutionary hotspots
Thierry Hoareau, Department of Biochemistry, Genetics and Microbiology
The world’s oceans play a central role in our lives as they provide oxygen, water, food and cultural services, regulate the global climate and support economic activities.
With the emerging concept
of ‘the Blue Economy’, first introduced at the Rio +20 United Nations Conference on Sustainable Development in 2012, several African coastal countries and islands have planned to exploit the full potential of the oceans’ resources. A major challenge is to preserve the health
of ocean ecosystems while unlocking economic growth to improve livelihoods and create jobs.
The reality is that the oceans are already disturbed by overfishing, destruction of habitats, pollution and sedimentation. Such disturbances are exacerbated by dense populations and high levels of growth and urbanisation in coastal areas. We cannot hope to protect what we overlook and do not understand. Preserving ocean ecosystems and marine biodiversity requires a better evaluation of the current biodiversity and the status of important marine species. This is essential if we wish
to research the sustainability of the oceans economy.
Dr Thierry Hoareau and his collaborators published an earlier
seminal study in the Journal of Biogeography. They had designed
a framework to identify marine evolutionary hotspots based on the use of phylogenetics, DNA barcoding and population genetics approaches. Evolutionary hotspots are regions characterised by large species diversity and evolutionary processes important to maintain and generate genetic biodiversity. Identifying such regions is crucial for conservation and management of ecosystems
as it guarantees maintenance of
the mechanisms at the source of biodiversity.
For the past few years, the research team has applied the same methods to other species, including reef brittle- stars and hydrozoans found in coral reefs in the Western Indian Ocean region. Using these new molecular tools has helped them detect an unexpected diversity of species. In
2018, Hoareau and his co-researchers published these results in the Journal of Biogeography. A total of 32 new species of brittle-stars and 37 new species of hydroids have been discovered, raising the number of surveyed species by 57% and 318%, respectively. Their studies suggest that the Western Indian Ocean should be considered as a marine evolutionary hotspot.
New applications of the framework will help in the search for evolutionary hotspots along the South African coastline, using linefish and invertebrates as targeted species.
Dr Hoareau anticipates that regions that are important for the dynamics of marine biodiversity will be detected, which will provide key information for the management of marine protected areas along the South African coastline, and help towards the goal of the sustainable use of our marine environment.
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