Past climate events provide informative case studies for understanding what is currently happening to the modern climate system. For this research, marine sediment core records across the Pacific Ocean were used to reconstruct the subsurface “footprint” of dissolved oxygen loss during abrupt global climate warming.
Like most of the life on the planet, the large majority of marine organisms need oxygen to live. Most marine life, from salmon, crabs, to shellfish, respires oxygen and many forms are intolerant of low oxygen seawater. Low oxygen zones have been incorrectly referred to as “dead zones.” In reality, they are host to bizarre ecosystems of extremophiles: worms, bacteria, and specialized urchins and bivalves colonize these harsh environments.
But, importantly, few commercially significant species of fish or shellfish can live within the low oxygen zones. So, if you are a microbial biologist you might be very excited to find a low oxygen zone, but if you are a commercial fisher person, that low oxygen zone represents a no-go environment for fishing.
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The new research ... found that entire ocean basins can abruptly lose dissolved oxygen in sync with other global-scale climate change indicators: temperature rise, atmospheric carbon concentration increases, and sea level rise.
From the Subarctic Pacific to the Chilean margin in the Southern Hemisphere, we found evidence of extreme oxygen loss stretching from the shallow upper ocean to about 3,000 meters deep in some regions. The transition from the last ice age to today’s warmer climate substantially reduced the oxygenated habitat of the global ocean and reorganized the distribution of marine life.
Read more at New Research Reveals Extreme Oxygen Loss in Oceans During Past Climate Change
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