Black areas in the Atlantic and Pacific oceans are unproductive "deserts."© NOAA
Scientists from the federal National Oceanic and Atmospheric Administration (NOAA) and the University of Hawaii unveiled new research last week showing that steadily warming sea surface waters are causing the least biologically productive swaths of the world’s oceans—so-called "ocean deserts"—to expand at an unprecedented rate (some 15 percent on average) over a nine-year period ending in 2007.
"The warming increases stratification of the ocean waters, preventing deep ocean nutrients from rising to the surface and creating plant life," the researchers said in a statement released by NOAA. The study was published last week in the peer-reviewed scientific journal Geophysical Research Letters. "These barren areas are found in roughly 20 percent of the world’s oceans and are within subtropical gyres—the swirling expanses of water on either side of the equator."
The scientists behind the new study think that the change is likely tied to human-induced global warming, although they acknowledge that a shorter as-yet undetected natural cycle could in theory also be to blame. Whatever the cause or causes, though, the expansion of ocean deserts—defined as expanses of salt water with low surface plant life—stands to further decimate populations of marine wildlife already on the ropes from decades of overfishing, pollution and other environmental trauma.
Source: NOAA News