Rather alarming signs of ecosystem stress on the Northwest’s coasts, reported in today’s Seattle Times. Temperatures are 2 to 5 degrees higher than normal, probably the result of the lack of "upwelling" that usually occurs in the spring and summer. (Those temperatures are normal readings for an El Nino year, but there’s no El Nino this year.) In normal years, cold water from the ocean’s depths rises to the surface carrying algae, krill, and other bottom-of-the-food-chain sustenance for small fish that in turn feed salmon and seabirds. This year: nothing.
The result is not pretty:
This spring, scientists reported a record number of dead seabirds washed up on beaches along the Pacific Coast, from central California to British Columbia… "This is somewhere between five and 10 times the highest number of bird deaths we’ve seen before," said Julia Parrish, an associate professor in the School of Aquatic Fisheries and Sciences at the University of Washington.
Some seabirds, like murres, are breeding very late or giving up. The dearth of food sources may also be partly responsible for the anemic salmon returns this year. But what’s causing the problem?
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Upwelling is caused by cold winds from the north. But this spring was warm and wet and the winds came from the southwest.
"In 50 years, this has never happened," said Bill Peterson, an oceanographer with the National Oceanic and Atmospheric Administration (NOAA) in Newport, Ore. "If this continues, we will have a food chain that is basically impoverished from the very lowest levels."
It may be tempting to blame global climate change for the disturbance—and, indeed, some scientists suspect that it is in play here. But ocean cycles and seasonal weather variations are so complex and variable that it is difficult to be certain that the alarming events on the coast are the fault of global warming. (And it is even tougher to say that they result from human-induced global warming.)
It seems to me, we’re in a frustrating dilemma. There’s little doubt that climate change will have a serious impact on ecosystems, yet we can never say for certain that any particular impact is the result of climate change.
In a similar vein, E magazine and CNNreport onscientific research from the UK’s Royal Society that carbon-dioxide emissions are not only warming the atmosphere, they are also increasing the acidity of the world’s oceans. Greater acidity makes life tough for coral, shellfish, and squid.
"The rising acidity of our oceans is yet another reason for us to be concerned about the carbon dioxide we are pumping into the atmosphere," said Professor John Raven, chair of the Royal Society working group on ocean acidification. "Failure to [cut emissions] may mean that there is no place in the oceans of the future for many of the species and ecosystems that we know today."