Jellyfish are taking over the oceans: Population surge as rising acidity of world’s seas kills predators
By David Derbyshire
3 December 2010 Britain’s beaches could soon be inundated with records numbers of jellyfish, marine experts warned today. Scientists say the number of jellyfish are on the rise thanks to the increasing acidity of the world’s oceans. The warning comes in a new report into ocean acidification – an often overlooked side effect of burning fossil fuel. Studies have shown that higher levels of carbon dioxide in the atmosphere doesn’t just trigger climate change but can make the oceans more acidic. Since the start of the industrial revolution, acidity levels of the oceans have gone up 30 per cent, marine biologists say. The new report, published by the UN Environment Programme during the Climate Change talks in Cancun, Mexico, warns that the acidification of oceans makes it harder for coral reefs and shellfish to form skeletons – threatening larger creatures that depend on them for food. The decline in creatures with shells could trigger an explosion in jellyfish populations. The report, written by Dr Carol Turley of Plymouth University, said: ‘Ocean acidification has also been tentatively linked to increased jellyfish numbers and changes in fish abundance.’ Jellyfish are immune to the effects of acidification. As other species decline, jellyfish will move in to fill the ecological niche. Populations have boomed in the Mediterranean in recent years. Some marine scientists say the changing chemistry of the sea is to blame. … The report says acidification may push overstressed oceans into disaster with far reaching consequences the billions of people who rely on fish as their main protein source. … ‘The basic chemistry of sea water is being altered on a scale unseen within fossil records over at least 20 million years,’ the report said. Oceans are naturally alkaline – and had a pH level of about 8.2 in 1750. Since the industrial revolution, the acidity has increased by 30 per cent. As more carbon dioxide enters the oceans it produces carbonic acid. As the acid breaks down it makes sea water less alkaline and more acidic. ‘If we continue at this rate, the ocean pH will decline by a further 0.3 by the end of this century, an unprecedented 150 per cent increase in ocean acidity,’ the report states. ‘This rate of change has not been experienced for around 65 million years, since the dinosaurs became extinct.’ …
