Growing low-oxygen zones in oceans worry scientists

[babylonsister]

Growing low-oxygen zones in oceans worry scientists

From Piscoweb.org


By Les Blumenthal | McClatchy Newspapers


WASHINGTON — Lower levels of oxygen in the Earth's oceans, particularly off the United States' Pacific Northwest coast, could be another sign of fundamental changes linked to global climate change, scientists say.

They warn that the oceans' complex undersea ecosystems and fragile food chains could be disrupted.

In some spots off Washington state and Oregon, the almost complete absence of oxygen has left piles of Dungeness crab carcasses littering the ocean floor, killed off 25-year-old sea stars, crippled colonies of sea anemones and produced mats of potentially noxious bacteria that thrive in such conditions.

Areas of hypoxia, or low oxygen, have long existed in the deep ocean. These areas — in the Pacific, Atlantic and Indian oceans — appear to be spreading, however, covering more square miles, creeping toward the surface and in some places, such as the Pacific Northwest, encroaching on the continental shelf within sight of the coastline.

"The depletion of oxygen levels in all three oceans is striking," said Gregory Johnson, an oceanographer with the National Oceanic and Atmospheric Administration in Seattle.

In some spots, such as off the Southern California coast, oxygen levels have dropped roughly 20 percent over the past 25 years. Elsewhere, scientists say, oxygen levels might have declined by one-third over 50 years.

"The real surprise is how this has become the new norm," said Jack Barth, an oceanography professor at Oregon State University. "We are seeing it year after year."

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http://www.mcclatchydc.com/2010/03/07/89918/growing-low-oxygen-zones-in-oceans.html

[HillbillyBob]

1. Nope, no climate change here.

This will likely soon start affecting larger areas, then river mouths where salmon have to traverse to get to their spawning areas. One the food chain is broken down it will be like domino, and I don't mean pizza either.