U.S. scientists say the longest, largest and most devastating hypoxic event ever observed in marine waters off the Oregon Coast has finally ended.
Oregon State University researchers say the event -- the fifth "dead zone" in five years -- was one for the record books, stretching farther north and reaching closer to shore than ever before.
More importantly, the scientists said, oxygen levels were by far the lowest ever recorded on the near shore of Oregon, approaching "anoxic" conditions in some places -- or the complete lack of oxygen.
"Given what's happened, it would not be surprising if hypoxic conditions developed next year as well, but we can't say that for sure," said Jack Barth, OSU professor of oceanic and atmospheric sciences.
When the system operates normally, upwelling off Oregon is usually a process that brings deep, cold, nutrient rich waters to the surface near the coast, resulting in one of the nation's more productive fisheries. When that process breaks down due to unusual winds, phytoplankton blooms that are healthy in moderation become too extreme, leading to concentrations of low-oxygen water near the sea floor.
Copyright 2006 by United Press International
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