Dead Zones Everywhere - Environment and Energy Since global warming hogs the environmental limelight, the fact that our oceans are also a mess often gets overlooked. But here's an eye-opener: According to a new study co-authored by the Virginia Institute of Marine Science's Robert Diaz, the number of "dead zones" in the ocean has roughly doubled every decade since the 1960s: Many coastal areas of the worlds oceans are being starved of oxygen at an alarming rate, with vast stretches along the seafloor depleted of it to the point that they can barely sustain marine life, researchers are reporting. The main culprit, scientists say, is nitrogen-rich nutrients from crop fertilizers that spill into coastal waters by way of rivers and streams. A study to be published Friday in the journal Science says the number of these marine dead zones around the world has doubled about every 10 years since the 1960s. About 400 coastal areas now have periodically or perpetually oxygen-starved bottom waters, many of them growing in size and intensity. Combined, the zones are larger than Oregon.... The trend portends nothing good for many fisheries, said Dr. Diaz, a professor at the Virginia Institute of Marine Science at the College of William and Mary. Dead zones, he said, "tend to occur in areas that are historically prime fishing grounds."