Scientific American: Hypoxic seawater from the deep ocean is moving into shallower near-shore environments off the Oregon coast, threatening or killing marine species that make their home there. 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 …