Ocean deserts

Anybody who has ever been scuba diving in the open waters of the Gulf of Mexico know that the bottom topography more closely resembles a desert than a forest. But a new study by scientists at the National Oceanic and Atmospheric Administration and the University of Hawaii show that the least biologically productive areas of the ocean may be expanding due to increased sea surface temperatures.

Between 1998 and 2007, the areas of low surface plant life in the Pacific and Atlantic Oceans grew by 15 percent or by an additional 6.6 million square kilometers. This expansion is occurring at the same time that sea surface temperatures are increasing about one percent each year.

These barren areas are now found in roughly 20 percent of the world's oceans and are typically withing subtropical gyres - vast, swirling areas of water on either side of the equator.

In the Pacific, the least productive areas are expanding from the center toward Hawaii. In the Atlantic, the "desert zone" is expanding from the Caribbean toward Africa.

Is this a natural cycle? Can humans do something to stop this warming trend? Nobody knows for sure, but following a few simple green rules that every first grader knows (reduce, re-use, recycle) surely can't hurt.