"A plague of oxygen-deprived waters from the deep ocean is creeping up over the continental shelves off the Pacific Northwest and forcing marine species there to relocate or die. Since 2002 tongues of hypoxic, or low-oxygen, waters from deeper areas offshore have slipped into shallower near-shore environments off the Oregon coast, although not close enough to be oxygenated by the waves. The problem stems from oxygen reduction in deep water, a phenomenon that some scientists are observing in oceans worldwide, and that may be related to climate change. "
"Deep-Ocean Low-Oxygen Zones Spreading to Shallower Coastal Waters"
Source: Scientific American, 02/24/2010