![]() You might still find some species there but they won’t be able to construct a reef any more. “The collapse of a reef means it becomes functionally extinct as a reef system. So, it’s really a 10-year horizon that we have to be concerned about,” he said. But while we estimate 50 years into the future, whether we can meet the 1.5C future or not depends on what we do in the next 10 years. “The most urgent threat is from climate change up to 50 years from now. Reefs in north Seychelles and along the entire east African coast were classified as vulnerable to collapse due to overfishing – especially of top predators – which is altering their ecology and promoting a build-up of different algae that can smother coral.ĭavid Obura, chair of the IUCN corals group, who led the study, said that while the global decline of coral reefs has been established for some time, region-specific assessments of specific regions provided greater clarity about the causes and the extent of the damage. Reefs in eastern and southern Madagascar, the Comoros and Mascarene Islands were all classified as critically endangered. The assessment found reefs in island nations in particular were highly threatened due to rising water temperatures driven by global heating, which is making bleaching events – when corals expel algae living in their tissue, causing them to turn completely white – more common. It analysed the health of 11 sub-regions using the International Union for the Conservation of Nature’s (IUCN) red list of ecosystems framework, akin to the method used to examine a plant or animal’s risk of extinction. Much of the interest in the past fortnight in the experience of South Africa, where Omicron was first identified, has been driven by reports from public and private hospitals and health providers that has suggested lower levels of hospitalisation, admission to ICUs and use of oxygen for patients.Īgainst the more optimistic claims that the fourth wave of Covid in South Africa might be less severe, in the past week there has been an uptick, so far small, in hospitalisations and deaths in South Africa’s hospitals.The study, published today in the journal Nature Sustainability, examined coral reefs in 10 countries around the western Indian ocean. While evidence from South Africa about the virulence of the Omicron variant is being studied around the world – including in the UK – the NICD’s Michelle Groome warned that the South African data could not necessarily be extrapolated to other countries with different population profiles. The question of immunity from vaccination or prior infection was flagged as a potential contributory factor last week by researchers at the University of Cape Town in a symposium of the World Health Organization after work that suggested that some of the body’s defences against Omicron – in particular so-called killer T-cells – may remain robust. “But we need more studies to be able to unpack these things,” she said. “The lower risk or lower proportions of severe disease we’re seeing in the fourth wave could be due to a number of factors including the level of prior immunity from people who’ve already gotten vaccinated or had natural infection, or it could also be due to the intrinsic virulence of Omicron,” said Dr Waasila Jassat, of the NICD.
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