The Caribbean gets Dusted: Spores and Nutrients from Africa's Sahel may be Killing Coral Reefs an Ocean Away

Ryan, John

African dust is nothing new to the Caribbean. Residents have long suffered through the occasional sinus-dogging haze or risen some mornings to find their islands coated in a thin layer of fine red powder. Dust carried by trade winds across the Atlantic from Africa's Sahel occasionally reduces visibility and reddens skies from Miami to Caracas, sometimes even forcing airports to close. Pre-Columbian natives in the eastern Bahamas crafted pottery from windborne deposits of African clay; agriculture in the Bahamas today depends largely on the red soils known as pineapple loam, composed of African dust deposited millennia ago. Though mariners and researchers ever since Darwin (see the box on page 335) have observed African particulates carried aloft hundreds of miles into the Atlantic, studies of atmospheric dust have focused mostly on its impacts on global heat budgets and carbon cycles. Only recently have researchers begun exploring the possibility that the hundreds of millions of tons of African aerosols landing annually in the Caribbean might have major, direct impacts on the region's marine ecosystems-and even on public health. With all the other forces working to unravel the Caribbean's ecosystems from global climate change to local water quality-some reef scientists and reef managers have seen the red dust as a red herring. But an increasing body of evidence, along with increasing loads of airborne pathogens and nutrients, is making it harder to ignore these transatlantic inputs to the troubled marine ecosystems of the Caribbean.

The Caribbean gets Dusted: Spores and Nutrients from Africa's Sahel may be Killing Coral Reefs an Ocean Away

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