Caribbean coral reef has 'flattened' since the 1970s A new study by researchers in the UK and Canada has shown that coral reefs throughout the Caribbean have been 'flattened' over the past 40 years. Their findings are published in the journal Proceedings of the Royal Society B. Healthy coral reefs contain millions of organism... A new study by researchers in the UK and Canada has shown that coral reefs throughout the Caribbean have been 'flattened' over the past 40 years. Their findings are published in the journal Proceedings of the Royal Society B. Healthy coral reefs contain millions of organisms that all play a part in the ocean's complex biodiversity. Their destruction has serious implications both for ocean biodiversity and coastal defences. Corals play a pivotal role in the life of the oceans by providing shelter, food and breeding grounds for a quarter of all the ocean's fish species and by helping to maintain coastal structures. Scientists have known about coral reef destruction for a long time, but the new study is the first large-scale and comprehensive overview of the phenomenon and its effects both on biodiversity and ocean and coastal defences. The research reveals that most reefs in the Caribbean region have lost their structure and formation in the past few decades and have become flatter, and that more complex reefs have almost been destroyed. The team, from the University of East Anglia in the UK and Canada's Simon Fraser University, analysed changes in 200 coral reef structures in the Caribbean using 500 surveys taken between 1969 and 2008. They found that 75% of the reefs are now mostly flat compared with the 1970s. 'The architectural complexity of Caribbean reefs has declined nonlinearly with the near disappearance of the most complex reefs over the past 40 years,' the study reads. 'The flattening of Caribbean reefs was apparent by the early 1980s, followed by a period of stasis between 1985 and 1998, and then a resumption of the decline in complexity to the present.' The surveys revealed that corals are affected at similar rates in shallow, mid-depth and deep waters. According to the researchers, two major events contributed substantially to the decline of the Caribbean coral reef. The first was a disease in the 1970s that spread through the waters between Florida and the Caribbean, in which 90% of Elkhorn and Staghorn corals were destroyed. The second event is climate change, which has led to increasing ocean temperatures and, accordingly, increased coral bleaching. This was particularly severe in 1998, which saw a worldwide 'bleaching event'. The main culprit in coral reef destruction is human activity. Overfishing, particularly the destructive practice of bottom trawling, has had devastating effects on coral reefs, often tearing off huge chunks of reef that will take thousands of years to grow back. Pollution from industrial and agricultural activities is also contributing to ocean acidification, which is highly destructive to corals. Even sunbathers are playing their part. Wearing sunscreen in the sea can damage coral, as the effect of the thousands of tonnes of sunscreen chemicals released into the ocean each year builds up. Lead researcher Lorenzo Alvarez-Filip of the University of East Anglia warned, 'This drastic loss of architectural complexity is clearly driving substantial declines in biodiversity, which will in turn affect coastal fishing communities. The loss of structure also vastly reduces the Caribbean's natural coastal defences, significantly increasing the risk of coastal erosion and flooding.' Countries Canada, United Kingdom
