PARIS – Conservationists fighting to save coastal coral reefs should think first about combating local deforestation rather than attacking the wider peril of global warming, suggests an unusual study published Tuesday.
Sediment washed downriver by tree-depleted land can cripple near-shore corals, as it clouds the water and diminishes the light on which coral communities depend.
When the sediment sinks to the seabed, it smothers the corals, forcing them to increase energy expenditure to survive, boosting the risk of “bleaching” and die-out.
A team led by Joseph Maina of Macquarie University in Sydney carried out a computer simulation of four river systems in Madagascar whose outflows have an impact on local coral ecosystems.
By 2090, global warming will have a big effect on these watersheds, reducing rainfall and as a result diminishing the deposit of sediment into the sea, they found.
“However, these climate change-driven declines are outweighed by the impact of deforestation,” says their paper.