Growing Pains

Many corals will be hit hard by climate change and acidifying oceans. But a new study has identified yet another factor that can slow down coral growth: air pollution.

The growth rate of corals can be influenced by the ocean’s temperature and the amount of sunlight that reaches them. And scientists believe that aerosols, a form of air pollution, affect the surface temperature of the North Atlantic Ocean.

The study authors examined coral growth data sets from Belize and Panama, each spanning roughly a century. As expected, growth rates appeared to be linked to sea surface temperature and sunlight. Aerosols may reduce the amount of sunshine that reaches corals by scattering light and making clouds “more reflective and longer-lasting,” the team writes.

At both locations, coral growth rates were partly driven by levels of human-generated aerosols, the authors report in Nature Geoscience. Aerosols had a stronger effect on sunshine in Belize than in Panama, perhaps because Belize is closer to the heavily-polluting US East Coast. Roberta Kwok | 9 April 2013

Source: Kwiatkowski, L. et al. 2013. Caribbean coral growth influenced by anthropogenic aerosol emissions. Nature Geoscience doi: 10.1038/ngeo1780.

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