afrol News, 20 September - New research pictures a grim future for the coral reefs of the Indian Ocean if the trends of global warming continue as today. A 1998 mass death of Indian Ocean corals due to high water temperatures provided evidence of a future extinction that could prove fatal for East Africa's coastal population.

Researcher Dr Charles Sheppard of the British University of Warwick has studied the outlooks of the economically and environmentally important coral reefs of the Indian Ocean since the 1998 disaster. His conclusions, published in the renowned journal 'Nature', are causing concern in the mostly poor nations bordering the ocean.

In 1998, over 90 percent of shallow-water corals on Indian Ocean reefs died because of higher than normal sea-surface temperatures, which had been caused by a strong "El Niño" phenomenon. Temperatures within a more normal range during the last five years however have let most of the reefs regenerate by now.

- A similar catastrophe may be 10–15 years away, according to a statement by the University of Warwick, and this is "a lot sooner than previously thought." The major concern is however that generally higher sea temperatures by then will not allow the reefs to regenerate.

Since the 1998 episode, scientists have been anxious to predict the timing of possible repeat events. By combining historical and predictive sea-surface temperature data for 33 Indian Ocean sites that were affected in 1998, Dr Sheppard created a sophisticated model of future coral mortality.

The sites potentially seeing the highest rises in sea-surface temperatures will not necessarily suffer the worst coral destruction, the model suggests. Also, areas predicted to be affected soonest include several of the world's poorest countries - these 'lethal' sea-surface temperatures could be just a decade away, the author says.

- The corals in these areas may not have enough time to recover from the 1998 event before being hit by another wave of mortality, Dr Sheppard suggests. However, the model predicts that should the corals become tolerant to temperatures 2 °C higher, the next lethal sea-surface temperatures rise might be pushed back decades.

Dr Sheppard further found that the area most probable to experience coral extinctions by about 2020 lies within a belt of the Indian Ocean between the Equator to about 15 or so degrees to the south. In Africa, this corresponds to the southern-most coast of Somalia, the entire Kenyan and Tanzanian coast, the northern coasts of Mozambique and Madagascar and the entire island states of Comoros and Seychelles.

- The prediction is particularly alarming because millions of people in the region rely on these reefs for their livelihood, Dr Sheppard says. Coral reefs and their abundant fish and shellfish resources are believed to be the main source of protein for millions of coastal dwellers in the developing world.

More than 100 million people depend on coral reefs for their livelihood in the entire Indian Ocean region. "The rate of recovery of the 'bleached' corals, and the risk of further episodes of ocean-warming in the future, are of vital importance to the populations in the region," Dr Sheppard warns in 'Nature'.

The evidenced trends of a warming planet earth are believed to be caused by man's emission of so-called greenhouse gases, mostly from the burning of fossil fuels. International efforts to halt or slowing up these emissions have been thwarted by several countries, most notably the US, and the oil industry.

By staff writer

© afrol News

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