Changing Climate: Deep Oceans Off Alaska Face Existential Threat

08/14/2011 05:22 pm ET | Updated Oct 14, 2011

If deep oceans covered an area only the size of the state of Alaska, then humans have so far explored in detail only about 2,400 square feet -- enough space to park seven or eight cars, according to details contained in a new report about the threats facing the Earth's watery abyss.

It may be a cliché, but people truly know less about the deep ocean floor than we do about the dark side of the moon. And little wonder.

With an average depth more than 3.8 kilometers, the global ocean could swallow 14 North Americas or 211 Alaskas whole. Of the deep areas, covering about 326 million square kilometers, almost nothing has been touched by human eyes or their robot arms. (Check out this story on deep sea exploration.)

The vast dark region below the waves is the largest and least visited environment on the home planet. It may be the least viewed habitat in the solar system.

"Of this great expanse, only the area equivalent to a few football fields has been sampled biologically," according to the team conducting the deep sea project for the Census of Marine Life. "The main problem is that we still know very little of what we call the deep sea, making it difficult to evaluate accurately the real impact of industrial activities, litter accumulation and climate change in the deep sea habitats."

But a new report in the journal PLOS one -- Man and the Last Great Wilderness: Human Impact on the Deep Sea -- warns that humans have begun to change the unknown abyss on a scale never seen before. And without protection and active management, it's going to grow worse.

Centuries of dumping waste -- sewage, garbage, chemicals, plastics, drugs -- has now morphed into industrial-scale fishing and accelerating resource extraction. Humans have introduced invasive species from one hemisphere to another, and global climate change has begun to alter the basic chemistry of marine life with dramatic increases in the concentrations of dissolved CO2 and overall world temperatures.

"As prospectors increase their efforts to exploit the resources locked up at the bottom of the oceans, scientists and legislators continue to lag behind, a panel of experts has warned," says a Nature news blog about the report. "From simply throwing waste over the side of ships, humanity has advanced to actively exploiting the deep sea." ...

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