Scientists have expressed concern that global climate change may
be accelerating low oxygen zones in oceans with disastrous consequences for sea life in the three oceans. Sounds really depressing:
be accelerating low oxygen zones in oceans with disastrous consequences for sea life in the three oceans. Sounds really depressing:
YahooNews!"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."
Barth and others say the changes are consistent with current climate-change models. Previous studies have found that the oceans are becoming more acidic as they absorb more carbon dioxide and other greenhouse gases.
"If the Earth continues to warm, the expectation is we will have lower and lower oxygen levels," said Francis Chan , a marine researcher at Oregon State .