Coral reefs under threat from humans
source : Many Science
Coral reefs under threat from human
Coral reefs under threat from humanA third of reef corals are threatened with extinction because of climate change and other human activities such as fishing and coastal development, scientists have warned.
A study published in the journal Science assessed 845 tropical reef-building species using the International Union for Conservation of Nature (IUCN) Red List criteria to evaluate their conservation status.
Of the 704 corals for which sufficient information existed to judge the risks they faced, 231 species or 32.8% were found to be threatened with extinction. Some 407 species were considered to be threatened or near threatened.
The Caribbean has the largest proportion of species in high extinction risk categories, the study said.
The authors said the results showed the extinction risks for corals had increased dramatically over the past decade, and now exceeded most terrestrial animal groups apart from amphibians.
The loss of reef corals would have huge impacts for hundreds of millions of people who depend on them for food, livelihoods and coastal protection, the researchers warned.
The scientists said the declines species were suffering were the result of rising carbon dioxide levels associated with climate change, as well as local human impacts.
The raised levels of CO2 increased sea surface temperatures, leading to "bleaching" of corals, and made the oceans more acidic which harms the coral's ability to build its skeleton.
Predictions by the Intergovernmental Panel on Climate Change (IPCC) for the increasing acidification of the oceans by the end of the century present "disastrous scenarios" for corals, one of the study's authors Alex Rogers said.
The research warned destructive fishing, sewage, coastal development and the use of agricultural chemicals were all reducing the ability of corals to withstand the threats caused by climate change and to rebuild reefs.