I have friends who deny that global climate change is happening, and others who concede that it seems to be happening, but say that it is part of natural cycles and deny that human activity is responsible. I can see either view as stemming from a natural emotion: inability or disinclination to run with the sheep in whichever direction the shepherds (or is it the wolves?) are indicating. There’s something to be said for that point of view. Most likely to me, though, is that human activity is interacting with natural cycles, sometimes to augment, sometimes to damp, what would be happening otherwise. If such is the case — and I strongly imagine that it is — surely it makes sense to reduce the levels of our impact when possible. (And surely it is no coincidence that spokesmen for those who are making the most money from the existing situation are among the loudest voices saying that nothing can/could/should be done to reduce the impact of human activity.)
The problem is, time may be short. Is it sensible to hold off reform pending greater certainty? And, on the opposite side of the coin, is it sensible to make moves when we don’t understand the situation? Prudence lies somewhere in between the extremes, it seems to me.
From the Seattle Post-Intelligencer: http://seattlepi.nwsource.com/local/351374_oceans15.html?source=mypi
Last updated February 14, 2008 10:21 p.m. PT
Scientists fear ‘tipping point’ in Pacific Ocean
Coast has seen deadly drop-off in oxygen levels for sea life
By ROBERT McCLURE
P-I REPORTER
Where scientists previously found a sea bottom abounding with life, two years ago they discovered the rotting carcasses of crabs, starfish and sea worms, swooshing from side to side in the current. Most fish had fled — and those that didn’t or couldn’t joined the deathfest on the sea floor.
Extraordinarily low oxygen levels were to blame — swept up from the deep ocean into normally productive waters just off the Pacific Northwest coast by uncharacteristically strong winds.
On Thursday scientists announced they had documented that low oxygen levels that killed the sea life in 2006 were the lowest in a half-century — and that for the first time, parts of the ocean off our coast were measured with zero oxygen in the water; 2007 looked only a bit better.
Strong winds and low oxygen levels have persisted for eight summers now, leading scientists to conclude that the ocean may be “poised for significant reorganization”– their way of saying an ecosystem gone awry.
It looks like the Pacific has reached a “tipping point,” a threshold where low-oxygen levels are becoming the rule, researchers said. And while scientists can’t prove it’s caused by a changing climate, that’s consistent with what is predicted by computer projections built to anticipate global warming.
“The real thing in the back of our minds is: Is this the first signs of what global warming might be like?” said Bill Peterson, a federal scientist and co-author of the research published in the journal Science. But because it’s not conclusive proof, he said, “We tried not to go there too much.”
Whatever the cause, it’s worrisome, researchers said, because shallow, productive ocean areas like those off the Northwest coast occupy just 1 percent of the globe’s oceans — yet produce 20 percent of the fish we eat.
“People keep asking us, ‘Is this situation really all that different or not?’ ” said Jane Lubchenco, a co-author and prominent ocean researcher, in a news release about the research.
“Now we have the answer to that question, and it’s an unequivocal ‘yes.’ The low oxygen levels we’ve measured in the last six years are abnormally low for our system. We haven’t seen conditions like this in many, many decades.”
Only once during the past seven years did the strong northerly winds of spring and summer go away — and that time, in spring and early summer of 2005, the pendulum swung wildly the other way, with little wind at all until partway through summer.
That set off a chain of events that scientists concluded were responsible for a startlingly widespread wave of seabird deaths — from the Farallon Islands off San Francisco to Vancouver Island.
After that, researchers from Oregon State University, the National Oceanic and Atmospheric Administration and the Oregon Department of Fish and Wildlife looked intensely at waters off the Oregon coast for the research announced Thursday. And the same thing is happening off Washington’s coast.
Mary Sue Brancato and her colleagues first noticed it on a visit to the coast in 2000 or 2001.
“We were out there for another (research) project and we were like, ‘What is it with these thousands of dead crabs?’ ” said Brancato, a marine biologist who works at the Olympic Coast National Marine Sanctuary.
Those were Dungeness crabs. Later other species were affected, Brancato said, leading scientists to surmise it was some widespread cause. By 2004 they were taking measurements to document low levels of dissolved oxygen, the kind of oxygen sea creatures can use.
By the time the biggest oxygen drop-off happened in 2006, it lasted for two weeks and researchers noted species of rockfish, eels and crabs normally found in deep water were along the coast instead, she said.
“It could be climate change, but we don’t have definitive proof of that,” Brancato said
She said the findings mirror a Canadian study that has been going on for 50 years that also detected declining dissolved oxygen levels.
Brancato was not on the team of researchers whose work is being published this week.
Those researchers had realized for years that they were seeing “really low” oxygen levels, said lead author Francis Chan.
“But the key is, what is the norm?” Chan said.
To ascertain that, Chan conducted a painstaking search for recordings of oxygen off the Northwest coast. He was able to find reliable records extending back into the 1950s.
“Now we know exactly what the norm looks like and we see that the kinds of values we’ve gotten (in 2000-2006) are really unprecedented for our system,” Chan said.
Oxygen levels in the spring and summer of 2007 also were depressed, but not as much as 2006.
The way the strong spring and summer winds reduce oxygen levels is complex. When these winds blow from the north as the Earth is turning toward the east, the water in the shallows along the coast is forced farther out to sea.
This allows water from deeper in the ocean — colder water with little oxygen but lots of nutrients — to seep up near the coast. It’s filled with nutrients because it contains dead plankton, fish excrement and more.
Once in the shallow water, these nutrients feed an explosion of one-celled plants. They die, falling to the bottom — only to fuel a massive buildup in bacteria that gobble up the oxygen while they eat the dead microscopic plants.
It’s possible that such low-oxygen periods occurred before reliable measurements were made starting in the ’50s, Chan said. But 50 years is enough time to have covered many oscillations between the El Niño and La Niña phases of ocean activity.
“If this was because of El Niño or La Niña cycles, we should have seen it in the past,” Chan said.
Researchers would like to find out now how much oxygen levels have varied over the course of tens of thousands of years around here. But already, Chan said, “if we look at the deeper past, it gives us an idea that changes in climate do lead to changes in the intensity of low-oxygen zones.
“Oxygen is such a basic, critical (need) for the ecological processes for marine life that changing that number in a rapid and dramatic way, is likely to have some big ecological consequences,” Chan said.
P-I reporter Robert McClure can be reached at 206-448-8092 or robertmcclure@seattlepi.com. Read his blog on the environment at datelineearth.com.
February 21st, 2008 at 6:45 pm
This isn’t helping:
http://www.truthout.org/issues_06/020608EB.shtml
The World’s Rubbish Dump: A Garbage Tip That Stretches From Hawaii to Japan
By Kathy Marks and Daniel Howden
The Independent UK
Tuesday 05 February 2008
A “plastic soup” of waste floating in the Pacific Ocean is growing at an alarming rate and now covers an area twice the size of the continental United States, scientists have said.
The vast expanse of debris - in effect the world’s largest rubbish dump - is held in place by swirling underwater currents. This drifting “soup” stretches from about 500 nautical miles off the Californian coast, across the northern Pacific, past Hawaii and almost as far as Japan.
Charles Moore, an American oceanographer who discovered the “Great Pacific Garbage Patch” or “trash vortex”, believes that about 100 million tons of flotsam are circulating in the region. Marcus Eriksen, a research director of the US-based Algalita Marine Research Foundation, which Mr Moore founded, said yesterday: “The original idea that people had was that it was an island of plastic garbage that you could almost walk on. It is not quite like that. It is almost like a plastic soup. It is endless for an area that is maybe twice the size as continental United States.”
Curtis Ebbesmeyer, an oceanographer and leading authority on flotsam, has tracked the build-up of plastics in the seas for more than 15 years and compares the trash vortex to a living entity: “It moves around like a big animal without a leash.” When that animal comes close to land, as it does at the Hawaiian archipelago, the results are dramatic. “The garbage patch barfs, and you get a beach covered with this confetti of plastic,” he added.
The “soup” is actually two linked areas, either side of the islands of Hawaii, known as the Western and Eastern Pacific Garbage Patches. About one-fifth of the junk - which includes everything from footballs and kayaks to Lego blocks and carrier bags - is thrown off ships or oil platforms. The rest comes from land.
Mr Moore, a former sailor, came across the sea of waste by chance in 1997, while taking a short cut home from a Los Angeles to Hawaii yacht race. He had steered his craft into the “North Pacific gyre” - a vortex where the ocean circulates slowly because of little wind and extreme high pressure systems. Usually sailors avoid it.
He was astonished to find himself surrounded by rubbish, day after day, thousands of miles from land. “Every time I came on deck, there was trash floating by,” he said in an interview. “How could we have fouled such a huge area? How could this go on for a week?”
Mr Moore, the heir to a family fortune from the oil industry, subsequently sold his business interests and became an environmental activist. He warned yesterday that unless consumers cut back on their use of disposable plastics, the plastic stew would double in size over the next decade.
Professor David Karl, an oceanographer at the University of Hawaii, said more research was needed to establish the size and nature of the plastic soup but that there was “no reason to doubt” Algalita’s findings.
“After all, the plastic trash is going somewhere and it is about time we get a full accounting of the distribution of plastic in the marine ecosystem and especially its fate and impact on marine ecosystems.”
Professor Karl is co-ordinating an expedition with Algalita in search of the garbage patch later this year and believes the expanse of junk actually represents a new habitat. Historically, rubbish that ends up in oceanic gyres has biodegraded. But modern plastics are so durable that objects half-a-century old have been found in the north Pacific dump. “Every little piece of plastic manufactured in the past 50 years that made it into the ocean is still out there somewhere,” said Tony Andrady, a chemist with the US-based Research Triangle Institute.
Mr Moore said that because the sea of rubbish is translucent and lies just below the water’s surface, it is not detectable in satellite photographs. “You only see it from the bows of ships,” he said.
According to the UN Environment Programme, plastic debris causes the deaths of more than a million seabirds every year, as well as more than 100,000 marine mammals. Syringes, cigarette lighters and toothbrushes have been found inside the stomachs of dead seabirds, which mistake them for food.
Plastic is believed to constitute 90 per cent of all rubbish floating in the oceans. The UN Environment Programme estimated in 2006 that every square mile of ocean contains 46,000 pieces of floating plastic,
Dr Eriksen said the slowly rotating mass of rubbish-laden water poses a risk to human health, too. Hundreds of millions of tiny plastic pellets, or nurdles - the raw materials for the plastic industry - are lost or spilled every year, working their way into the sea. These pollutants act as chemical sponges attracting man-made chemicals such as hydrocarbons and the pesticide DDT. They then enter the food chain. “What goes into the ocean goes into these animals and onto your dinner plate. It’s that simple,” said Dr Eriksen.
February 23rd, 2008 at 10:54 am
What isn’t helping? Posting it? The content itself? Don’t understand your comment.