Coral reef ecosystems 'in danger'
Climate change experts have warned that acidifying oceans will severely hit coral reefs by the end of the century. According to the scientists, rising greenhouse gas emissions are threatening the existence of coral reef ecosystems around the world. The report is based on new findings from volcanic seeps; fissures that leak gases and minerals into the ocean. The study highlighted the effects on coral reefs of three natural carbon dioxide (CO2) seeps in Papua New Guinea. The water is turning more acidic due to the seeps, the effects of which are similar to that of carbon dioxide caused by human activities. The experts pointed out that pH values dropped from 8.1 to 7.8, indicating an increase in acidity levels. At values below 7.7, reef development ceased altogether. Climate change experts estimate that by the end of the century, ocean acidity worldwide will change in a similar way because of CO2 emissions. Authors of the new research, writing in the journal Nature, said the effect of a pH drop below 7.8 would be "catastrophic" for the coral. Chris Langdon - from the University of Miami in the US, who led the seep reef research - said: "These 'champagne reefs' are natural analogues of how coral reefs may look in 100 years if ocean acidification conditions continue to get worse. "The seeps are probably the closest we can come to simulating the effect of man-made CO2 emissions on a coral reef. They allow us to see the end result of the complex interactions between species under acidic ocean conditions."