Another Inconvenient Truth - Human Destroying Sea Life

Peering into the murky depths, Jane Lubchenco searched for sea life, but all she saw were signs of death.

Video images scanned from the seafloor revealed a boneyard of crab skeletons, dead fish and other marine life smothered under a white mat of bacteria. At times, the camera's unblinking eye revealed nothing - a barren undersea desert in waters renowned for their bounty of Dungeness crabs and fat rockfish.

"We couldn't believe our eyes," Lubchenco said, recalling her initial impression of the carnage brought about by oxygen-starved waters. "It was so overwhelming and depressing. It appeared that everything that couldn't swim or scuttle away had died."

Upon further study, Lubchenco and other marine ecologists at Oregon State University concluded that that the undersea plague appears to be a symptom of global warming. In a study published in the journal Science, the researchers note how these low-oxygen waters have expanded north into Washington and crept south as far as the California state line. And, they appear to be as regular as the tides, a cycle that has repeated itself every summer and fall since 2002.

The median nesting date for loggerhead turtles on Florida’s east coast, for example, has advanced 10 days in only 15 years; likewise, far up the Atlantic coast in Maine, the median date of capture of Atlantic salmon and alewife in two rivers has advanced more than a day per year in just 15 years. For both the turtles and the fishes, these advances in timing may create poorer matches to food sources — one more potential stress for species already in sharp decline.

A poster species for the seriousness of these invasions is the freshwater zebra mussel in North America. In its native Eurasian range it exists in balance with other aquatic creatures. But in New York's Hudson River these mussels went from zero to an estimated 550 billion individuals in only two years. Zebra mussels now reduce the river's phytoplankton by more than eighty percent, an ecological insult that echoes through its food chain, including reducing available food for newly hatched shad and striped bass.

Rising sea temperatures have disrupted the animals' home habitat in the waters between Alaska and Russia, said Wayne Perryman, a researcher at the Southwest Fisheries Science Centre in La Jolla, California. Because of these changes, the whales are spending more time in the north before they start their yearly swim south

"This isn't trivial," Perryman said. "It's a significant change."
Richard Ternullo, a boat captain for Monterey Bay Whale Watch in Monterey, California, said the whales' yearly arrival in the bay fluctuates, but he has noticed on average it has drifted about 10 days later into the year.