Madagascar's major reefs among most at risk from climate change

Posted on 04 December 2009
Coral reefs in the Coral Triangle
Tuléar, Madagascar – An unprecedented combination of climate change and increasing human pressures could have a devastating effect on coral reefs in the near shore areas of Southern Madagascar.

A study commissioned by WWF modeled current threats to the coral reef system to determine its future vulnerability to climate change.

The Tuléar reef is the third largest in the world, and one of only five large continuous reef systems in the world.

The reef ecosystem houses an extreme abundance of different marine species including nearly 400 fish species and over 300 coral species. Whales and dolphins pass through the reef system and marine turtles graze on the reefs and nest on the surrounding beaches. The blue spotted bamboo shark, which is endemic to Madagascar, is another species that might suffer when temperatures rise and fish stock dwindles.

People who depend on fishery on their livelihood, the majority of the region’s population, would also suffer severely.

“A destruction of the reef would leave tens of thousands of people in jeopardy, with severe impact on their main source of income or adequate food supplies,” said Gaëtan Tovondrainy, head of the marine project with WWF Tuléar.

“With increasing global temperatures, the corals within Tuléar reef could succumb to massive bleaching events and become infested with green algae. The latter would smother the coral and therefore reduce feeding opportunities for fish. “

According to the study the Tuléar reef ecosystem is one of the most vulnerable sites in the western Indian Ocean. While some of the reefs around the smaller islands are in good conditions, others near estuaries are degraded from the sediments caused by deforestation upstream. These human pressures act to make the reefs more vulnerable to the threats of climate change.

The global phenomenon of coral bleaching in 1998 primarily affected the reefs in the northern part of the region such as the Seychelles and Comoros. But nowadays climate change affects other reefs as well.

“Increased bleaching of corals and green algae invasions are two direct effects of climate change on these important ecosystems and they can be seen clearly around Tuléar” Tovondrainy said.

The reef system is vital for the community’s survival. This region is home to people from the group who traditionally migrate up and down the coast in line with seasonal changes. Nearly 20,000 traditional fishermen and 15,000 canoes operate on the Tulear reef system.

This traditional form of resource use is being threatened and migrants from inland areas affected by drought and deforestation increase competition for resources.

“It is poor countries like Madagascar that have contributed the least to the problem but will suffer the worst consequences. If we can’t stop climate change, the collapse of the Tuléar reef system is just one of many severe consequences for the local population” says Tiana Ramahaleo, head of the WWF Conservation Science and Species Programme in Madagascar. “That’s why we desperately hope for a good deal in Copenhagen”

Coral reefs in the Coral Triangle
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