This article was written before the triple tragedy in Japan, March, 2011. Now with a large radioactive plume moving farther out in the North Pacific currents every day, the issues examined here mean even more. -Editor
The ice and snow that has persisted all week here in the hills is thawing at last. The air is still. The profound quiet tells me that the easterly air flow has weakened. When the wind is in the east, we hear the hum of the distant freeway and the pleasanter sounds of train whistles. Perhaps it will rain in a day or two. I’ll miss the pretty patterns of thin ice stretched across puddles, the ice sculptures and tiny castles rising out of the mud, and the glistening frosty mushrooms which I know will dissolve into black slime once they thaw. But rain will be welcome. Even though the soil is saturated and the creeks and rivers are running full, our land wants more. West of the Cascades the Pacific Northwest is a water world. Its trees and all the green things in the forest want lots of water for as many months as possible. The summer is almost a dormant season. In the Valley, those sodden lawns and squishy paths are telling you; “We are wetlands. Once we were swamps and the river swallowed us many winters. We want to touch the water before it flows to the sea.”
The sea. In all my life I have never lived farther from the sea than I do now. I crave it to be near it, to wade and swim in it, to smell the brine and scents of life, to stare at the endlessly changing wave patterns and colors. It is the source of such incredible life. It seems eternal, a comfort, though not comfortable. Home to the first life, teaming with countless plankton, photosynthesizing plants and their predators, producing oxygen, storing carbon. What a perfect balance. It is inconceivable that we could ruin the ocean, that anything could fundamentally change it.
Of course we know that we are changing the ocean. The water that flows from the land is filled with chemicals and toxic minerals which we produce, and which are to be found in the tissues of creatures in the remotest seas. Rivers which once flowed to the sea like the Colorado, flow no more, and the Sea of Cortez is more saline and stagnant because of the dams and irrigation projects that rob a river dry. Closer to home, imagine the huge delta that passes San Francisco as it enters the sea. Imagine it without dikes, salt evaporation ponds, elaborate patchwork quilts of housing and farming projects. Imagine it clean, teaming with birds and fish, its waters edged with beautiful grasses and trees. Imagine it the color of real water. We know what we have done. We know that human induced global warming is causing sea levels to rise and coastal estuaries to flood. We know that the huge increase in atmospheric carbon dioxide in this century is acidifying the ocean waters to such an extent that mollusks grow thin and fragile shells. Species like cod that once fed the world are now close to extinction. But what most of us do not know is far worse.
We assume that the oceans of the earth have always been as they are now, oxygenated from surface to bottom, suitable for life as we know it, dependent on oxygen, if of the animal kingdom, or if of the plant kingdom, using carbon and sunlight to photosynthesize, producing oxygen as the byproduct of this metabolism. The Black Sea is not quite like this. Its deep waters are anoxic. Like the dead zones we have created off our Gulf Coast, no species dependent on oxygen can live at its depths. There, species of bacteria metabolizing sulfur and producing hydrogen sulfide thrive. Imagine what would happen if the Black Sea became entirely anoxic. The sulfur-dependent bacteria would multiply faster in the surface sun and warmth. They would send out clouds of hydrogen sulfide gasses, poisonous to sea and land creatures alike. Imagine if the depths of all the oceans became anoxic. Or if all of all the oceans became anoxic. It could happen. It has happened, according to many paleontologists.
Peter Ward specializes in extinctions. He has published on the Permian extinction with Greg Retallack, and has done much to refute the notion that asteroid impacts can explain all mass extinctions. Under A Green Sky, Smithsonian Books, 2007 is a splendid but chilling analysis of our planet’s slide towards another mass extinction. Ward recalls that though the world’s oceans were thoroughly anoxic in the earliest days of life on earth, fossil sedimentary rocks contain chemical markers indicating the dominance of sulfur metabolizing life forms in later times. Oceans experienced periods of anoxia during the Permian extinction and the Jurassic-Triassic boundary extinction. Other lesser periods of extinction such as that ending the Paleocene epoch, also show indications of ocean anoxia. Should the surface waters of the oceans cease to be oxygenated, the results are mass extinctions. Clouds of hydrogen sulfide gasses rising from the sea destroy the earth’s ozone layer, and the sun’s un-filtered rays kill the photosynthesizing plankton and land plants alike. On land and sea, animals starve or succumb to the difficulties of living in a very low oxygen atmosphere.
How could this happen to us? We take for granted our wonderfully oxygenated oceans but this is perhaps their less common state over the history of the planet. Today’s ocean currents carry cooler fresher water down from the icy north, mixing it with equatorial currents bringing warm water to the surface. But what if there were no cold icy waters, if all the glaciers were gone? Then warm oxygen-poor saline water would settle to the bottom. The currents would slow, the winds would die. And sulfur loving bacteria would become dominant. But what could cause the glaciers to melt? We can all answer that question; rapid increases of greenhouse gasses like carbon dioxide and methane. Volcanoes spew forth gasses. So do the activities of six, seven, ten billion humans. We cannot explain away the possible near future mass extinction phenomena on eruptions of lava over thousands of square miles, such as formed the Siberian Traps at the end of the Permian. But rapid though the changes to our planet may be, we will not live to see the end of life as we know it. And we can do a lot to slow the rise of greenhouse gasses, to mitigate our destructive practices on land and sea, to help others get closer to nature and to feel as passionate as we do about saving species. And when it all just feels too depressing, go to the beach. Take deep breaths and check out the pelicans. They used to be so rare. Now they are everywhere. See, we can do good things, sometimes.
Reida Kimmel gardens and raises animals on the Fox Hollow side of Spencer Creek Valley. Many of her articles first debut in <a href=”http://biology.uoregon.edu/enhs/frame.html”>The Eugene Natural History Society</a> Newsletter. See some of her article listed under Writers.
First published March, 2011.