The Mystery of Oregon's 'Dead Zone'

Roland Piquepaille writes "The area off Cape Perpetua on the central Oregon coast is now a gigantic crab and fish graveyard. It was first discovered in 2002, but according to the Christian Science Monitor, researchers at Oregon State University (OSU) have taken a close-up look into this coastal dead zone. And things are getting worse. A few weeks ago, the researchers measured the level of dissolved oxygen in this part of the ocean. They found that levels were 10 to 30 times lower than normal, down to 0.5 milliliters per liter, a characteristic of hypoxia. And because they have no explanations about this phenomenon, they're even envisioning a total absence of oxygen, or anoxia. Read more for additional details and pictures about this mystery."

Comments

No explanation?

[broothal]

" And because they have no explanations about this phenomenon..."

Let me help them out here a bit then. The Oregon zone appears when the wind generates strong currents carrying nutrient-rich but oxygen-poor water from the deep sea to the surface near shore, a process called upwelling. The nutrients encourage the growth of plankton, which eventually dies and falls to the ocean floor. Bacteria there consume the plankton, using up oxygen.

No - I'm not so smart that I knew the answer, but google did - first (and several more) hit.

Re:No explanation?

[tigheig]

Yes. It was discussed. Starting in the fifth paragraph of the linked article.

Follow the link, it's a good article.

Re:No explanation?

[enharmonix]

Hmm, we've been dealing with this in the Gulf for a while. It's recurrant - it goes away, then comes back the next year, and is caused by too much algae, which is basically fed by nitrogen rich runoff from ground water. IIRC, though, wind actually helps by mixing the water, so global warming shouldn't really enter into this picture. Not to say the article didn't quote somebody saying that, or that different climates won't affect things, but that's just what I heard. For anybody interested, there's a pretty scientific assessment of the phenomenon (in the gulf at least) here (I don't think anybody's linked to this yet, apologies if this is a dupe). Anyway, don't panic, Oregonians, you'll survive! Cheers.

Re:No explanation?

[Anonymous Coward]

Y'know, maybe you should just read TFA, where this explaination is given:

To be sure, the jury is still out on that connection, says Jane Lubchenco, a marine zoologist at Oregon State University who is heading up this day-long expedition. But, she adds, what she and her colleagues see is consistent with projections of global warming's effects on coastal winds in the spring and summer, which drive upwelling of nutrient-laden water.

These effects - identified as early as 1990 by researcher Andrew Bakun, then with the National Oceanic and Atmospheric Administration's fisheries lab in Monterey, Calif. - turbocharge the upwelling. This overloads the waters with nutrients and spawns large algae blooms. The algae sink, die, and decompose, in a process that sucks oxygen out of the water and the topmost layer of sediment on the bottom, where many worms and shellfish live.

Hey, that's exactly what the OP said!

Re:No explanation?

[Luminus]

The Atlanta Journal-Constitution had an article (google cache if needed) about georgia's dead zone about two weeks ago,
and claimed that the solution in this case was actually quite obvious:

Verity and other scientists who have researched similar changes worldwide say they can sum up the cause in a single word: people.

As more homes, condominiums, marinas and businesses are built on the coast, pollution increases in tidal creeks and estuaries. Treated sewage discharges and storm water runoff carry fertilizers from lawns, golf courses and farms and oil and other pollutants from pavement and rooftops.

"We need to stop what we're doing now and either mitigate or reduce [the impacts] because we're going downhill in a hurry," Verity said.

---------------
Other bits of the article follow....

For 20 years, a scientist near Savannah has taken weekly water samples from the same dock, giving him a composite snapshot of the estuary's health.
Pieced together, the view goes from good to fair and getting worse. Peter Verity's data tells him the estuary --- where rivers wrestle with the sea --- is in trouble.
Dissolved oxygen, the breath of life for shrimp, blue crabs, oysters and fish, is declining at an alarming rate. Within 10 years, Verity, a professor at the Skidaway Institute of Oceanography, predicts there won't be enough left for the sea life we love to eat. Those creatures will be replaced by jellyfish, which don't need as much dissolved oxygen and feed on the type of organisms that grow in a polluted estuary, he says.

Verity's already witnessed change. Between 1987 and 2000, his sampling showed a 70 percent increase in jellyfish.

Verity and other scientists who have researched similar changes worldwide say they can sum up the cause in a single word: people.

As more homes, condominiums, marinas and businesses are built on the coast, pollution increases in tidal creeks and estuaries. Treated sewage discharges and storm water runoff carry fertilizers from lawns, golf courses and farms and oil and other pollutants from pavement and rooftops.

"We need to stop what we're doing now and either mitigate or reduce [the impacts] because we're going downhill in a hurry," Verity said.

Verity presented his dissolved oxygen research in June at an international conference of his peers and published it this month in an academic journal, Estuaries and Coasts. His bottom line: Georgia's bays and inlets, lined with tidal marshes now teeming with infant and juvenile sea life, is headed toward hypoxia, a dead zone incapable of supporting shellfish and fish.

Hypoxia is already severe at times in the Gulf of Mexico off the Louisiana coast and in the Chesapeake Bay near Washington. An associated problem, harmful algae blooms that release fish-killing toxins, has affected virtually every coastal state, threatening human health and dealing economic blows to seafood industries worldwide.

volcanic ridge/rift, most likely

[nido]

I guess it's called the Juan de Fuca Ridge.

This dead zone is "most likely caused by underwater volcanism along the Juan De Fuca Ridge, which is about 20% volcanic along its 500 mile length. Occassional volcanic eruptions occur along the Ridge (Rift) which can create gigantic megaplumes of hot mineral water. Could be there is very little oxygen in the plumes, it most likely would have reacted with the minerals, leaving dissolved oxygen at nil."

Re:USA IS IGNORANT!

[DrSkwid]

Lets not forget that China & India are also not signees.

Thus the three most populous continents on earth are simply not concerned.

No mystery - Polution

[PietjeJantje]

From the article:

"This overloads the waters with nutrients and spawns large algae blooms. The algae sink, die, and decompose, in a process that sucks oxygen out of the water and the topmost layer of sediment on the bottom, where many worms and shellfish live."

Fosfate/nitrate (among others) --> Nutritions for algae --> No oxygen

The "mystery" is where the polution is coming from.

Re:No mystery - Polution

[canuck57]

The "mystery" is where the polution is coming from.

It is also possible the whales, or lack of them play a part. Would say 500 missing whales eat a lot of plankton and algae? This would mean there would not be as much to fall and rot.

Maybe oil from Alaska leaking from old rusty tankers.

Maybe someone saved some disposal costs and dropped in 50 barrels of toxic waste.

I have seen this on interior freshwater lakes where in 1968 the water was clear, fresh and loaded with large and small fish. In 1998 I was back to the same lake in the same place, the loads of algae made it like a slime bog and the fish were scrawny, few and small. The mine shut down in 1996 and some heavy fine laws on human waste going into the lake was enforced and the lake appears to be slowly coming back.

Probably a combination of factors, but mankind is behind most.

Re:CSM or ZDNET - Which is it?

[Anonymous Coward]

This is nothing new. Roland Piquepaille has been submitting stories which invariably link to his own blog (which carries a pale imitaiton of the original article) for ages. There have been accusations that he is paying the slashdot editors for the service of publishing his stories. See http://www.google.com/search?q=roland.piquepaille+ site:Slashdot.org.

Re:CSM or ZDNET - Which is it?

[dublain]

Both. The first link is to CSM. The next link is to ZD providing additional information, as the link says. Mebbe lay off the coffee/stimulants and try to be a bit less indignant and accusatory. Bitching isn't commenting. And someone modded it 5 - insightful?

It's just Roland the Plogger screwing up again

[Animats]

That's just a link to a Roland the Plogger blog, who doesn't understand the problem. Read the New York Times story, which has important facts the Plogger missed, like the fact that this has been happening for the past five years. The local paper, the Register-Guard, has a good story. "On the way down, the camera lens illuminates a nighttime blizzard, a flurry of broken chunks of plankton called "marine snow." This is evidence of what caused this year's hypoxia - an onslaught of nutrients brought to shallow coastal waters by wind-driven currents, whose decomposing structures suck up available oxygen."

This is no mysterious dramatic event. It happens every year, but this year, it's worse than usual, possibly because ocean currents have shifted due to weather.

dead zones

[falconwolf]

Hmm, we've been dealing with this in the Gulf for a while. It's recurrant - it goes away, then comes back the next year, and is caused by too much algae, which is basically fed by nitrogen rich runoff from ground water.

The same thing happens between Cape Cod and Cape Hatteras and it's believed runoff from the factory farming of pigs may be responsible. Something I've been wondering about is runoff is responsible for the dead zone in the Gulf and it's harming fishermen out of New Orleans and other towns why don't they get together and sue the farmers upstream.

Falcon