How mangrove forest conversion is killing Earth

You may want to stop creating those man-made ponds or pastures as a recent study has revealed that clear-cutting of tropical mangrove forests contributes significantly to the greenhouse gas, like carbon, one of the leading causes of global warming.

The researchers concluded that mangrove conversion to agricultural uses resulted in a land-use carbon footprint of 1,440 pounds of carbon dioxide released into the atmosphere for the production of every pound of beef; and 1,603 pounds of released carbon dioxide for every pound of shrimp.

"On a personal scale, this means a typical steak and shrimp cocktail dinner produced through mangrove conversion would burden the atmosphere with 1,795 pounds of carbon dioxide," said lead study author J. Boone Kauffman from Oregon State University.

"This is approximately the same amount of greenhouse gases produced by driving a fuel-efficient automobile from Los Angeles to New York City," Kauffman added.

The findings, published in the journal Frontiers in Ecology and the Environment.

The results were derived by the researchers through development of a new measurement - the land-use carbon footprint - by measuring the amount of carbon stored in the intact mangrove forest, the greenhouse gas emissions rising from conversion, and the quantity of the shrimp or beef produced over the life of the land use.

Mangroves are a group of trees and shrubs that live in tropical coastal intertidal zones.

All of these trees grow in areas of waterlogged soils, where slow-moving waters allow fine sediments to accumulate.

The study was conducted on 30 relatively undisturbed mangrove forests and 21 adjacent shrimp ponds or cattle pastures.

The sites were in Costa Rica, the Dominican Republic, Honduras, Indonesia and Mexico.

Shrimp ponds were sampled in all countries except Mexico, where the predominant land use was conversion to cattle pastures.

The decline in carbon storage from mangrove conversion to shrimp ponds or cattle pastures exceeded the research group's previous estimates.

"These forests have been absorbing carbon for the last 4,000 or 5,000 years and now through deforestation they have become significant sources of greenhouse gas emissions," Kauffman explained.

"Because they store so much carbon that is released as greenhouse gases when deforested they are important sites for protection in order to mitigate or slow climate change," he noted.