23 Jul 2010:
Map Illustrates Extent
of the Planet’s Marine Dead Zones
A new NASA map illustrates the significant expansion of the world’s marine dead zones
regions where dissolved oxygen is so low marine species cannot survive. Many of these dead zones occur off densely populated coastlines, particularly along the eastern United States and in Northern Europe. Scientists produced the map using data from satellites that can detect high concentrations of particulate matter, an indicator of overly fertile waters that can create dead zones. The zones arise when fertilizers applied to crops wash into streams and rivers, eventually reaching coastal waters, where the excess nutrients trigger massive algae blooms. When the algae die, they sink to the ocean’s depths, where they essentially become fertilizer for microbes that decompose the organic matter and consume oxygen, suffocating marine life. In 2008, a study found that dead zones had spread exponentially
since the 1960s, affecting more than 400 ecosystems and a total area of more than 152,000 square miles (245,000 square kilometers).
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A three-part series Tainted Harvest
looks at the soil pollution crisis in China, the threat it poses to the food supply, and the complexity of any cleanup. Read the series.
is now available for mobile devices at e360.yale.edu/mobile
The Warriors of Qiugang
, a Yale Environment 360
video, chronicles a Chinese village’s fight against a polluting chemical plant. It was nominated for a 2011 Academy Award for Best Documentary Short.
Watch the video.
Top Image: aerial view of Iceland
. © Google & TerraMetrics.
, winner of the Yale Environment 360 Video Contest, documents the work of African researchers monitoring wildlife in Uganda's remote Bwindi Impenetrable National Park. Watch the video.