The Mystery of Oregon's 'Dead Zone' 235
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."
No explanation? (Score:4, Informative)
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.
volcanic ridge/rift, most likely (Score:4, Informative)
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! (Score:5, Informative)
Thus the three most populous continents on earth are simply not concerned.
No mystery - Polution (Score:5, Informative)
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:in other news... (Score:1, Informative)
That said, the Monitor is usually not biased toward any fundementalist, creationist-only, everyone-else-bad viewpoint. I deride you for your blatant and closed-minded attack, sir.
Re:No explanation? (Score:4, Informative)
Follow the link, it's a good article.
Re:No explanation? (Score:5, Informative)
Re:CSM or ZDNET - Which is it? (Score:5, Informative)
Re:No mystery - Polution (Score:3, Informative)
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? (Score:2, Informative)
It's just Roland the Plogger screwing up again (Score:5, Informative)
That's just a link to a Roland the Plogger blog, who doesn't understand the problem. Read the New York Times story [nytimes.com], 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 [registerguard.com]. "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.
Re:No explanation? (Score:3, Informative)
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!
dead zones (Score:3, Informative)
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.
FalconThis is nothing new. (Score:1, Informative)
There's nothing new about oceanic dead zone
By Terry Thompson
A so-called "dead zone" off the Oregon Coast is in the news again. According to reports, this is the fifth time in five years such a zone has developed. This year's zone is larger than those of the previous two years, and for the first time, a similar zone has been detected in the waters off of Washington state.
"Dead zone" is a catchy phrase. It brings to mind images of man-caused pollution and ecological disaster. But we should be calling this a "live zone," because it's the beginning of ocean life.
I'm basing my observations on both my undergraduate marine biology studies at Oregon State University and more than 4,000 days of firsthand experience at sea, much of it in and around the area in question. I've had several questions from people about the dead zone, about red tides, about what these two developments mean, and about whether they're related. It has convinced me that more people might be wondering about this.
During a normal year, strong northwest winds cause cold water, rich in nutrients but low in oxygen, to upwell from the deep ocean. That water from below mixes with oxygen-rich water near the surface, causing some phytoplankton growth and providing the basis for a thriving fishery and a healthy marine food chain.
When the wind dies back and currents are disrupted, this process is also disrupted. That causes too much phytoplankton growth and development of a "dead zone."
The "dead zone" is really a case of too much of a good thing, sort of like overindulging in food - your body just can't effectively process it all. The same thing happens in the ocean.
Large masses of plant growth die and decay, and in the process consume even more of the available oxygen near the sea floor. In the short term, there's too little oxygen and too much phytoplankton. The results can be dramatic and appear to be a cause for concern. Dead bottom fish litter the beaches. Crabbers have told me about pulling up hundreds of dead crabs in their gear.
Meanwhile, unusual numbers of large Dungeness crabs are turning up in the bays. They may be trying to escape the "dead zone."
But this is only part of the story.
The scientists claim this phenomenon is just a few years old. But I believe it's been occurring as long as there's been a temperate ocean. The researchers are backing up their conclusions with fishermen's logbooks dating back to the 1950s. But there's a key flaw in this.
Until recent years, crabbers weren't working the offshore waters in the summer. Until fairly recently, the salmon fleet dominated this area in the summer months, and they wouldn't have discovered any signs of these conditions. They would have simply found no fish and moved on.
I have my own memories of the 1950s. I recall seeing whiting floating in Yaquina Bay, gasping for air. This wasn't a rare occurrence. People who lived here will remember the dead fish that littered the beaches.
Another important thing to remember is that while there is loss of marine life in a relatively small area, the upwelling phenomenon is occurring along the entire coastal shelf. I believe it will prove to be healthy in the long run. Without it, we'd lose the building blocks of our nutrient-rich Northwest oceans. This is precisely what happens in El Niño years.
Most of the ocean floor in the primary "dead zone" area immediately south of Newport is a mud plain, with a rocky ridge to the north and west, a formation similar to the edge of a bowl. When these nutrients fall to the bottom, it makes the mud even richer.
In winter, following the development of the "dead zone" area, sandabs and English sole go there to reproduce. The mud is filled with little worms on which the baby fish can feed. I've observed large numbers of juvenile sole in this area in the past, and I fully expect to find abundant marine life in the "dead zone" again next winter.
Red tide is also l
Re:No explanation? (Score:2, Informative)
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.
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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.