Dead Zone map of the world - 1969, 1989 and 2009

http://www.vims.edu/newsandevents/topstories/archives/2010/diaz_dead_zone_report.php

Global Hypoxia 1969: Global pattern of coastal hypoxia in 1989. Each red dot represents a documented case related to human activities. Use scroll arrows to compare with similar data from 2009 and 1969.

Diaz contributes to White House "dead zone" report

by David Malmquist |  September 3, 2010

Research by Professor Bob Diaz of the Virginia Institute of Marine Science lies at the heart of a new White House report on the growing problem of low-oxygen marine "dead zones." The report, released today to Congress and the public by the President's Office of Science and Technology Policy, notes that low oxygen dead zones now affect nearly half of the 647 U.S. waterways assessed for the report, up from 38 percent reported in the 1980s.

 Diaz was lead author for the report's chapters on the science, economics, and societal impacts of marine dead zones.  He was one of  only 3 academic researchers involved in the report's development.

The report is the final of 5 reports mandated by Congress in the Harmful Algal Bloom and Hypoxia Amendments Act of 2004 and isavailable online through the White House Office of Ocean Science & Technology.

Biologists find 'dead zones' around BP oil spill in Gulf

http://www.guardian.co.uk/environment/2010/jun/30/biologists-find-oil-spill-deadzones

Methane at 100,000 times normal levels have been creating oxygen-depleted areas devoid of life near BP's Deepwater Horizon spill, according to two independent scientists.

Scientists are confronting growing evidence that BP's ruptured well in the Gulf of Mexico is creating oxygen-depleted "dead zones" where fish and other marine life cannot survive.

In two separate research voyages, independent scientists have detected what were described as "astonishingly high" levels of methane, or natural gas, bubbling from the well site, setting off a chain of reactions that suck the oxygen out of the water. In some cases, methane concentrations are 100,000 times normal levels.

--------------------------------------------

Diatoms can provide the oxygen required by bacteria.

Gulf oil spill could widen, worsen 'dead zone'

Gulf oil spill could widen, worsen 'dead zone' (w/ Video)

June 7, 2010

Enlarge

A NASA satellite image recorded May 24 showing areas of oil approaching the Mississippi River delta, shown in false color to improve contrast.

(PhysOrg.com) -- While an out-of-control gusher deep in the Gulf of Mexico fouls beaches and chokes marshland habitat, another threat could be growing below the oil-slicked surface.

Ads by Google

Production Equipment - We maintain, refurbish, prepare and test your subsea equipment - www.AGR.com

The nation’s worst oil spill could worsen and expand the oxygen-starved region of the Gulf labeled “the dead zone” for its inhospitability to marine life, suggests Michigan State University professor Nathaniel Ostrom. It could already be feeding microbes that thrive around natural undersea oil seeps, he says, tiny critters that break down the oil but also consume precious oxygen.

“At the moment, we are seeing some indication that the oil spill is enhancing hypoxia,” or oxygen depletion, Ostrom said. “It’s a good hint that we’re on the right track, and it’s just another insult to the ecosystem - people have been worried about the size of the hypoxic zone for many years.”

The dead zone is believed to stem from urban runoff and nitrogen-based fertilizers from farmland swept into the Gulf by the Mississippi River. Higher springtime flows carry a heavier surge each year, nourishing algae bloomsthat soon die and sink. Those decay and are eaten by bacteria that consume more oxygen, driving out marine life and killing that which can’t move, such as coral. The dead zone can grow to the size of a small state.

With the spill overlapping a section of the dead zone, the impact on that region is unknown. As it happened, Ostrom earlier had tapped zoology major Ben Kamphuis to be on the Gulf in late May for a research cruise focused on nitrogen cycling. When the British Petroleum Deepwater Horizon offshore drilling rig blew out and sank April 20, Ostrom and collaborator Zhanfei Liu from the University of Texas at Austin quickly landed federal support to expand their inquiry.

Animals not requiring Oxygen

http://www.treehugger.com/files/2010/04/first-oxygen-free-animal-discovered-marine-dead-zone.php

First-Ever Animals Found Living Without Oxygen in Marine Dead Zone
by Brian Merchant, Brooklyn, New York on 04. 8.10
SCIENCE & TECHNOLOGY

Life Will Find a Way . . .

You're likely familiar with the ever-growing marine dead zones, areas in the ocean where no life was believed possible due to depleting oxygen levels. But in a truly startling discovery, scientists have stumbled upon the first animal that can survive without oxygen--a feat that until now was only possible in bacteria. This has a number of implications: both regarding the possibility that life may yet adapt to more severe conditions on earth, and on whether life is possible on other oxygen-free planets--and may be more abundant than we thought.

It looks like a tiny jellyfish in a protective shell. It measures around a single millimeter. And it can survive and reproduce without any oxygen at all. The new species of Loriciferan, named already named Spinoloricus Cinzia after the wife of the scientist who discovered it, and it could be the biggest biological discovery in recent times.

The BBC reports that scientists from the Marche Polytechnic University in Italy found the creature in the Mediterranean Sea's L'Atalante basin--which is "about 3.5km (2.2m) deep and is almost entirely depleted of oxygen, or anoxic." They collected some specimens, which they incubated in an oxygen-free environment--and the eggs hatched successfully in the complete absence of oxygen.



The Oxygen-Free Animal
From the BBC:

"It is a real mystery how these creatures are able to live without oxygen because until now we thought only bacteria could do this," said Professor Danovaro, who heads Italy's Association of Limnology (the study of inland waters). "We did not think we could find any animal living there. We are talking about extreme conditions - full of salt, with no oxygen." The discovery of the new Loriciferans represents, he said, a "tremendous adaptation for animals which evolved in oxygenated conditions".
This discovery is especially important when paired with the facts that these marine dead zones are doubling in size around the world every 10 years. This is happening largely because of human activity (of course); it's the result of nitrogen-rich sewage spewing into the coastlines across the globe.

A partial map of marine dead zones--where oxygen-free creatures may yet flourish. Via NASA

Marine Dead Zones
The New York Times has a good explanation of what happens:

Nitrogen from agricultural runoff and sewage stimulates the growth of photosynthetic plankton on the surface of coastal waters. As the organisms decay and sink to the bottom, they are decomposed by microbes that consume large amounts of dissolved oxygen. Most animals that live at the bottom of the coastal ocean cannot survive as oxygen levels drop.
And this is happening all around the world (global warming has been found to play a major role, too). With oxygen-deprived areas expanding, it therefore becomes imperative for sea life to adapt to survive without it--which may be what has happened with this Loriciferan. We'll have to see what details emerge about the creature's life cycle, but needless to say, this could be big. The scientists say that it could additionally help them better understand the possibilities of life existing on other planets with radically different atmospheres. In other words, this probably helps the case that it's out there.

Environmental groups seek fix for Gulf dead zone

http://www.houmatoday.com/article/20100331/ARTICLES/100339834/1211/NEWS01?Title=Environmental-groups-seek-fix-for-Gulf-dead-zone

Environmental groups seek fix for Gulf dead zone

By Nikki Buskey
Staff Writer

Published: Wednesday, March 31, 2010 at 12:05 p.m.

HOUMA — Farmland runoff is creating an “environmental disaster” in the Gulf of Mexico, and state and federal agencies should strengthen agricultural-pollution regulations to rectify that, environmental groups say.

The Environmental Law and Policy Center and the Mississippi River Collaborative released a joint report this week called “Cultivating Clean Water.” The report examines the effectiveness of state regulatory programs that control agricultural pollution and recommends policies the groups say will result in cleaner water.

The dead zone, an annual phenomenon in which oxygen is sucked from a swath of Gulf waters, is blamed on fertilizer and other farming-related chemicals that find their way into the Mississippi River. The runoff drains into the Gulf of Mexico where, once combined with warm water and summer temperatures, it creates an area of low-to-no-oxygen incapable of sustaining plant and marine life. Creatures are forced to flee the dead zone or die.

“We live at the mouth of the Mississippi and Atchafalaya rivers, so we’re getting pollution from 42 percent of the nation flowing past us,” said Matt Rota, water-resources director with the Gulf Restoration Network.

The report focuses on nitrogen and phosphorus pollution because the Environmental Protection Agency considers those the most harmful. The two also trigger massive algal blooms in the Gulf. Those blooms eventually die, sucking oxygen from the water as they decompose.

“Louisiana could do a better job of making an outcry, saying that we have this major environmental disaster on our hands,” Rota said.

The report points out the country has a fragmented and poorly implemented state-based agricultural-pollution regulations. Currently, most programs attempting to curb runoff are voluntary. Farmers typically get an incentive if they take part, but participation isn’t mandated.

Environmental officials said targeted, money-backed programs could play an important role in reducing water pollution.

“It is clear that voluntary programs alone will not get the job done and funding for voluntary programs continues to fall under the budget knife,” said Craig Cox, of the Environmental Working Group.

The report examines existing state programs and suggests five commonsense practices:

n Vegetative buffers between farmland and water.

n Buffers between fertilizer and manure applications and waterways.

n Restrictions on winter applications of manure.

n Keeping livestock out of water bodies.

n Restrictions on applying fertilizer in fall.

The report says several states have regulations to control agricultural pollution, though all fall short on enforcement and monitoring due to small budgets, limited staff and political resistance.

“We need to make cleaning up these watersheds a priority,” Rota said.

Whitney Broussard, a researcher at The University of Louisiana at Lafayette, said the solution is a multi-agency and multi-state cooperation.

“A watershed problem, like the dead zone in the Gulf of Mexico, requires a watershed approach, and watersheds pay no attention to political lines,” Broussard said.

Nikki Buskey can be reached at 857-2205 or nicole.buskey@houmatoday.com.

Role of Increased Marine Silica Input on Paleo-pCO2 Levels

http://www.agu.org/journals/pa/v015/i003/1999PA000427/

PALEOCEANOGRAPHY, VOL. 15, NO. 3, PAGES 292–298, 2000

Role of Increased Marine Silica Input on Paleo-pCO2 Levels

Kevin G. Harrison
Geology and Geophysics Department, Boston College, Chestnut Hill, Massachusetts

Abstract

Changing the supply of silica to the ocean may alter pCO2 levels. The increase in dust delivered to the ocean during glacial times increased the availability of silica for biological uptake. The increased silica levels shifted species composition: Diatom populations increased and coccolith populations decreased. Decreasing the population of coccoliths decreased the flux of calcite to the sediments, which, in turn, lowered pCO2 levels enough to explain the glacial-interglacial pCO2 transition. Furthermore, the contemporary increase in dust delivered to the ocean’s mixed layer may be removing significant amounts of carbon dioxide from the atmosphere at present. To set the stage, this silica hypothesis is compared with the iron fertilization and nitrogen fixation hypotheses.

---------------

Silica flow into oceans has decreased in 20th Century and has not increased, this is one of the causes of Dead Zones in estuaries and coastal waters and for fish kills and harmful algal blooms in lakes and rivers.

The reduction is silica is both actual and in proportion to N and P flow.
Dams reduce the amount of silt flowing down rivers and higher agricultural activity results in higher N and P flow down rivers.

Its well documented that in River Mississippi Si : N ratio was 3 : 1 fifty years ago and not its < 1 : 1. This has resulted in the Gulf of Mexico Dead Zone.

World's Largest Dead Zone Suffocating Sea

http://news.nationalgeographic.com/news/2010/02/100305-baltic-sea-algae-dead-zones-water/



James Owen in Stockholm
for National Geographic News
Published March 5, 2010

This story is part of a special series that explores the global water crisis. For more clean water news, photos, and information, visit National Geographic's Freshwater Web site.

"Eagle!" The shout goes up as a great shadow sweeps over our boat. The white-tailed eagle makes its descent to one of the 24,000 islands that make up Sweden's pine-covered, rocky Stockholm Archipelago.

The tourists on board for this nature tour in August 2009 mostly miss the photo opp. But local wildlife expert Peter Westman, of the conservation group WWF Sweden, assures the group that there will be others.

Numbers of this once-threatened predator have soared from 1,000 to more than 23,000 in the Baltic Sea (map) since pollutants including DDT, an eggshell-thinning pesticide, and PCBs, chemical compounds used in electrical equipment, were banned in the 1970s, Westman said.

But there is a new danger to the eagle and many other marine species: An explosion of microscopic algae called phytoplankton has inundated the Baltic's sensitive waters, sucking up oxygen and choking aquatic life.

Though a natural phenomenon at a smaller scale, these blooms have recently mushroomed at an alarming rate, fed by nutrients such as phosphorous and nitrogen from agricultural fertilizers and sewage. When it rains, farm fertilizers are washed into the sea. Sewage-treatment facilities also discharge waste into the Baltic ecosystem.

As a result, the Baltic is now home to seven of the of the world's ten largest marine "dead zones"—areas where the sea's oxygen has been used up by seabed bacteria that decompose the raining mass of dead algae.

"We’ve had enormous algal blooms here the last few years which have affected the whole ecosystem," Westman said.

Overfishing Adding to Algal Blooms

Overfishing of Baltic cod has greatly intensified the problem, Westman said. Cod eat sprats, a small, herring-like species that eat microscopic marine creatures called zooplankton that in turn eat the algae.

(Related: "Overfishing is Emptying World's Rivers, Lakes, Experts Warn.")

So, fewer cod and an explosion of zooplankton-eating sprats means more algae and less oxygen.

This vicious cycle gets worse as the spreading dead zones engulf the cod’s deep-water breeding grounds, he added.

The algal blooms, which can be toxic to animals and human swimmers, leave behind an ugly layer of green scum that fouls tourist beaches and starves seaweeds of light.

"Other species have taken the place [of cod], which don’t provide as good habitats for fish," especially juveniles, Westman said. "In the past couple of years common fishes like pike and perch have had virtually no reproduction in the inner part of the archipelago."

This vicious circle gets worse as the spreading algal blooms engulf the cod’s breeding grounds.

Too Late to Save the Baltic Sea?

Back in Stockholm, it's World Water Week, the annual global meeting on water issues organized by the Stockholm International Water Institute. On a conference room wall is a satellite image of the Baltic Sea, its deep blue edges giving way to a swirling, milky center that shows the algal blooms.

World Water Week attendees are pushing a new action plan called the Baltic Sea Strategy. The European Union-led initiative will attempt to coordinate the efforts of the eight EU members within the nine Baltic states—not including Russia—to revitalize their shared sea.

While the speakers all agree "it’s time for action," they don’t sound optimistic.

"It might well be too late," said Søren Nors Nielsen of the University of Copenhagen.

The planet’s youngest sea at less than 10,000 years old, the Baltic is unique in that it formed after the last ice age. It's also one of the world’s largest bodies of brackish water.

"Experience tells us such a system is almost impossible to predict," Nielsen said.

The Baltic Sea's unusual mix of fresh water and marine species means it's also especially vulnerable to environmental changes. "Evolution didn’t have time to develop an ecosystem able to tolerate flux," Nielsen explained.

(Related: "Viking Shipwrecks Face Ruin as Odd 'Worms' Invade.")

"Sea of Laws"

Water-law attorney Megan Walline of the Stockholm International Water Institute, who spoke at the Baltic Sea presentation, said there's already "a sea of laws" for dealing with human activities that threaten the Baltic.

Too numerous to list, they include existing EU directives that cover nutrient pollution and illegal fishing. The laws are there, they just need to be implemented, she said.

For his part, WWF’s Westman hopes the new EU strategy will at least turn the Baltic into "a kind of test area for enforcing and implementing the directives." For instance, the plan calls for phasing out phosphates in laundry and kitchen detergents, and putting in place more sustainable fishing regulations.

Even so, "There are no quick fixes, unfortunately," Westman concludes, reaching for his binoculars.

Seems it’s back to the eagles for now.

Dead Zones Doubling Every Decade

http://www.livescience.com/environment/etc/091008-dead-zones-doubling-every-decade.html


Dead Zones Doubling Every Decade
Submitted by LiveScience Staff
posted: 08 October 2009 03:04 pm ET

Global distribution of the more than 400 marine systems with dead zones caused by increased nutrient runoff. Their distribution matches the current human "footprint" in the northern hemisphere. In the southern hemisphere, dead zones have only been reported recently.

Earth's oceans currently have more than 400 dead zones, oxygen-starved areas that are hundreds or thousands of square miles and virtually devoid of life during summer months.

The tally is doubling every decade, according to the National Science Foundation.

Most dead zones, including one in the Gulf of Mexico, are caused by pollution that is dumped into oceans by rivers. It works like this:

Each year, spring runoff washes nitrogen-rich fertilizers from farms in the Mississippi River basin and carries them into the river and the streams that feed it. The nitrogen eventually empties out of the mouth of the Mississippi and into the Gulf of Mexico, where tiny phytoplankton feed off of it and spread into an enormous bloom.

When these creatures die, they sink to the ocean floor, and their decomposition strips the water of oxygen. This condition, called hypoxia, prevents animals that depend on oxygen, such as fish or shrimp, from living in those waters. In recent years, this so-called "dead zone" has grown to the size of New Jersey—about 20,000 square kilometers (7,700 square miles)—each summer.

But there's another emerging culprit, the NSF explains in a new special report. Every summer since 2002, the Pacific Northwest's coastal waters -- one of the U.S.'s most important fisheries -- has seen massive dead zones believed to be caused by an entirely different and surprising phenomena: changes in oceanic and atmospheric circulation that may, in turn, be caused by climate change.

Dead Zones contribute to Nitrous Oxide

'Dead-zone' microbe measures ocean health

http://www.cbc.ca/technology/story/2009/10/22/tech-climate-ocean-dead-zone-microbe.html

"Specifically, SUP05 removes toxic sulphides from the water and fixes carbon dioxide, but we also think it's producing nitrous oxide, which is a more potent greenhouse gas than either carbon dioxide or methane," Hallam said.

------------------------------------
there are over 400 dead zones in all the oceans of the world.

SOS: Is Climate Change Suffocating Our Seas?

http://www.redorbit.com/news/science/1767833/sos_is_climate_change_suffocating_our_seas/

SOS: Is Climate Change Suffocating Our Seas?

Posted on: Saturday, 10 October 2009, 08:36 CDT

Scientists work to explain why massive "dead zones" have been invading the Pacific Northwest's near-shore waters since 2002

Yet another ecological scourge may earn a place on the ever-lengthening list of problems potentially caused by climate change: the formation of some so-called "dead zones"—huge expanses of ocean that lose virtually all of their marine life at depth during the summer.

Possible connections between climate change and the relatively recent formation of dead zones in the Pacific Northwest's coastal waters are currently being studied by a research team that is funded by the National Science Foundation and co-led by Jack Barth of Oregon State University (OSU) and Francis Chan of OSU. (Jane Lubchenco, who is currently on leave from OSU while serving as the Administrator of the National Oceanic and Atmospheric Administration, also previously co-led the team.)

WORLDWIDE DEAD ZONES

The Earth currently has more than 400 oceanic dead zones, with the count doubling every decade. A single dead zone may cover tens of thousands of square miles.

Dead zones form where microscopic plants, known as phytoplankton, are fertilized by excess nutrients, such as fertilizers and sewage, that are generated by human activities and dumped into the ocean by rivers, or more rarely, where they are fertilized by naturally occurring nutrients. The result: blooms of organic matter that ultimately decompose through processes that rob the ocean of life-sustaining oxygen. Animals that fail to flee dead zones either suffocate or suffer severe stress.

--------------------------
The reference to Phytoplankton is not entirely correct - Cyanobacteria and Dinoflagalletes may lead to fall in DO level, but Diatom Algae leads to increase in DO level. They do not die and decompose, they are consumed by zooplankton or fall to the ocean floor.

This distinction is not being made by most people.
The solution is to get the right type of Phytoplankton to bloom - Diatom Algae.

Pacific Ocean 'dead zone' in Northwest may be irreversible

http://www.latimes.com/news/nationworld/nation/la-na-oregon-ocean9-2009oct09,0,4615320.story

Pacific Ocean 'dead zone' in Northwest may be irreversible
Oxygen depletion that is killing sea life off Oregon and Washington is probably caused by evolving wind conditions from climate change, rather than pollution, one oceanographer warns.

By Kim Murphy
October 9, 2009

Reporting from Corvallis, Ore. - An oxygen-depleted "dead zone" the size of New Jersey is starving sea life off the coast of Oregon and Washington and will probably appear there each summer as a result of climate change, an Oregon State University researcher said Thursday.

The huge area is one of 400 dead zones around the world, most of them caused by fertilizer and sewage dumped into the oceans in river runoff.

But the dead zone off the Northwest is one of the few in the world -- and possibly the only one in North America -- that could be impossible to reverse. That is because evolving wind conditions likely brought on by a changing climate, rather than pollution, are responsible, said Jack Barth, professor of physical oceanography at OSU.

"I really think we're in a new pattern, a new rhythm, offshore now. And I would expect [the low-oxygen zone] to show up every year now," Barth said at a news conference.

Thursday's briefing coincided with the release of a National Science Foundation multimedia report that said the number of dead zones worldwide was doubling every decade.

In the Pacific Northwest, the report said, the areas of hypoxic, or low-oxygen, water that long have existed far offshore began to appear closer to land in 2002, a phenomenon that may mean they are even deadlier to sea life that exists near the ocean floor.

Low-oxygen zones are created when large blooms of plankton form on the surface of the ocean, then decay and fall to the sea floor, where further decay eats up the oxygen in the water.

"When oxygen gets too low in the ocean, it has a deleterious effect on organisms," Barth said. "They either have to flee the area, or they get stressed or even die off. Those die-off [areas] are dead zones."

The affected waters of the continental shelf in Oregon and Washington for the most part are not inundated with polluted river runoff; the nutrients that feed the plankton blooms here come from natural sources, Barth said. And researchers believe a change in the flushing movement of water along the coastline may be responsible.

The gradual warming of surface waters across the north Pacific, the report funded by the National Science Foundation said, has tended to isolate deep waters far below the surface -- allowing less oxygen penetration.

There also has been a change in wind patterns, encouraging the upwelling of that low-oxygen water and inhibiting the natural flushing action of water.

"What we're seeing is changes in the oxygen content of the water and the winds that drive the ocean and cause that flushing," Barth said, calling it a "double whammy."

Although it is possible that the phenomenon could be related to cyclical ocean currents and temperatures, Barth said that he was more inclined to believe it was a long-term result of climate change. He said that researchers had scanned records going back to the 1950s and had seen nothing similar to what has appeared every year off the Oregon coast since 2002.

The worst year on record was 2006, when the Pacific Northwest zone saw an area of "anoxia," or virtually no oxygen at all.

kim.murphy@latimes.com

Mississippi State gets D+ for Protecting Water Quality

http://www.jacksonfreepress.com/index.php/site/comments/state_gets_d_for_protecting_water_quality_090309/

State gets D+ for Protecting Water Quality

The multi-million dollar shrimp and fishing industries have been severely affected by state's lack of protection for waters emptying into the Gulf.

by Adam Lynch

September 3, 2009

Mississippi rates a lowly D+ for protecting the quality of natural water sources, according to the Gulf Restoration Network. The organization, an alliance of local individuals and national and regional groups, issued a report card grading how committed (or non-committed) state officials are at incorporating the standards of the Clean Water Act of 1977. The Clean Water Act established goals of reducing national water pollution and eliminating the release of water fouled with high amounts of toxic waste.

Source of nutrients in Gulf of Mexico

http://water.usgs.gov/nawqa/sparrow/gulf_findings/primary_sources.html

Source of Nitrogen and Phosphorus in the Gulf of Mexico

Source Nitrogen (%) Phosphorus (%)

Corn and Soyabean crops 52 25
Other Crop 14 18
Pasture and range 5 37
Urban and population-related sources 9 12
Atmospheric deposition 16 -
Natural Land 4 8

Farmers use fertilzers to grow more crops and part of this is used to feed fish.
The fertilizer run off causes harmful algal bloom and this reduces fish population.

Instead if Nualgi is used the excesss fertilizer in water can be converted into fish feed via Diatom Algae and fisheries use of corn or soya meal as fish feed will reduce.

Diatoms are also source of biodiesel.

Thus many problems can be solved at one go.

Blue Legacy - Louisiana: Downstream dead zone

Blue Legacy - Louisiana: Downstream dead zone

Dead Zones

Virginia Institute of Marine Sciences

http://www.vims.edu/newsandevents/topstories/2008-dead-zones-spread.php

Diaz and Rosenberg write “There’s no other variable of such ecological importance to coastal marine ecosystems that has changed so drastically over such a short time as dissolved oxygen.”

-------------
We can only reply.
There is no solution that increases Dissolved Oxygen as dramatically as Nualgi and Diatom Algae.

The Diatom Story - Video

A 20 minute video about Diatoms and Nualgi is available on youtube in two parts.

The links are -

http://www.youtube.com/watch?v=r8M6eV9-7OA
http://www.youtube.com/watch?v=xp7KV310slI

Earth's Biogeochemical Cycles

http://www.earth-stream.com/outpage.php?s=18&id=188819

Earth's Biogeochemical Cycles, Once In Concert, Falling Out Of Sync

ScienceDaily (Aug. 4, 2009) — What do the Gulf of Mexico's "dead zone," global climate change, and acid rain have in common? They're all a result of human impacts to Earth's biology, chemistry and geology, and the natural cycles that involve all three.

On August 4-5, 2009, scientists who study such cycles--biogeochemists--will convene at a special series of sessions at the Ecological Society of America (ESA)'s 94th annual meeting in Albuquerque, N.M.

They will present results of research supported through various National Science Foundation (NSF) efforts, including coupled biogeochemical cycles (CBC) funding. CBC is an emerging scientific discipline that looks at how Earth's biogeochemical cycles interact.

"Advancing our understanding of Earth's systems increasingly depends on collaborations between bioscientists and geoscientists," said James Collins, NSF assistant director for biological sciences. "The interdisciplinary science of biogeochemistry is a way of connecting processes happening in local ecosystems with phenomena occurring on a global scale, like climate change."

A biogeochemical cycle is a pathway by which a chemical element, such as carbon, or compound, like water, moves through Earth's biosphere, atmosphere, hydrosphere and lithosphere.

In effect, the element is "recycled," although in some cycles the element is accumulated or held for long periods of time.

Chemical compounds are passed from one organism to another, and from one part of the biosphere to another, through biogeochemical cycles.

Water, for example, can go through three phases (liquid, solid, gas) as it cycles through the Earth system. It evaporates from plants as well as land and ocean surfaces into the atmosphere and, after condensing in clouds, returns to Earth as rain and snow.

Researchers are discovering that biogeochemical cycles--whether the water cycle, the nitrogen cycle, the carbon cycle, or others--happen in concert with one another. Biogeochemical cycles are "coupled" to each other and to Earth's physical features.

"Historically, biogeochemists have focused on specific cycles, such as the carbon cycle or the nitrogen cycle," said Tim Killeen, NSF assistant director for geosciences. "Biogeochemical cycles don't exist in isolation, however. There is no nitrogen cycle without a carbon cycle, a hydrogen cycle, an oxygen cycle, and even cycles of trace metals such as iron."

Now, with global warming and other planet-wide impacts, biogeochemical cycles are being drastically altered. Like broken gears in machinery that was once finely-tuned, these cycles are falling out of sync.

Knowledge about coupled biogeochemical cycles is "essential to addressing a range of human impacts," said Jon Cole, a biogeochemist at the Cary Institute of Ecosystem Studies in Millbrook, N.Y., and co-organizer of the CBC symposium at ESA.

"It will shed light on questions such as the success of wetland restoration and the status of aquatic food webs. The special CBC conference sessions at ESA will explore future research needs in environmental chemistry, with a focus on how global climate change may impact various habitats."

Earth's habitats have different chemical compositions. Oceans are wet and salty; forest soils are rich in organic forms of nitrogen and carbon that retain moisture.

The atmosphere has a fairly constant chemical composition--roughly 79 percent nitrogen, 20 percent oxygen, and a 1 percent mix of other gases like water, carbon dioxide, and methane.

"Seemingly subtle chemical changes may have large effects," said Cole.

"Consider that global climate change is caused by increases in carbon dioxide and methane, gases which occupy less than ½ of one percent of the atmosphere. Now more than ever, we need a comprehensive view of Earth's biogeochemical cycles."

The study of coupled biogeochemical cycles has direct management applications.

The "dead zone" in the Gulf of Mexico is one example. Nitrogen-based fertilizers make their way from Iowa cornfields to the Mississippi River, where they are transported to the Gulf of Mexico. Once deposited in the Gulf, nitrogen stimulates algal blooms.

When the algae die, their decomposition consumes oxygen, creating an area of water roughly the size of New Jersey that is inhospitable to aquatic life. Protecting the Gulf's fisheries--with an estimated annual value of half-a-billion dollars--relies on understanding how coupled biogeochemical cycles interact.

A better understanding of the relationship between nitrogen and oxygen cycles may help determine how best to use nitrogen fertilizers, for example, to avoid dead zones.

Gulf of Mexico Dead Zone - A Video

Gulf of Mexico and Chesapeake Bay Dead Zones 2009

Revised estimates of Gulf and Chesapeake Bay Dead Zones

http://www.nytimes.com/2009/07/28/science/earth/28zone.html?_r=1

Dead Zone in Gulf Is Smaller Than Forecast but More Concentrated in Parts

By HENRY FOUNTAIN
Published: July 27, 2009

Scientists said Monday that the region of oxygen-starved water in the northern Gulf of Mexico this summer was smaller than forecast, which means less disruption of shrimp, crabs and other marine species, and of the fisheries that depend on them.

But researchers found that although the so-called dead zone along the Texas and Louisiana coasts was smaller — about 3,000 square miles compared with a prediction of about 8,000 square miles — the actual volume of low-oxygen, or hypoxic, water may be higher, as the layer is deeper and thicker in some parts of the gulf than normal. And the five-year average size of the dead zone is still considered far too big, about three times a target of 2,000 square miles set for 2015 by an intergovernmental task force.
...........

http://weblogs.baltimoresun.com/features/green/2009/07/bay_dead_zone_bigger_than_pred.html

Bay 'dead zone' bigger than predicted
The fish-stressing "dead zone" in the Chesapeake Bay is bigger than predicted this summer, scientists say.

Just about a month ago, University of Michigan scientists had forecast that the amount of oxygen-starved water in the Chesapeake should be much lower than average for the troubled estuary. University of Maryland scientists had followed with similar predictions that the bay's ''dead zone'' -- where dissolved oxygen levels in the water are too low for fish to breathe comfortably, if at all -- was likely to be one of the smallest ever measured.

The scientists had based their predictions on below-normal flows in late spring of the Susquehanna River, which supplies half of the fresh water entering the bay. Though it rained a lot in Maryland and Virginia in May and June, it had been relatively dry in the Susquehanna's drainage basin in New York and Pennsylvania.

But based on water sampling conducted every two weeks since May, University of Maryland scientists hve found that the volume of water with little or no oxygen in it has exceeded the forecast -- increasing from below-average in late May to above normal for June and remaining about average for this month, even as rains locally subsided.
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Gulf of Mexico Dead Zone

News about the Gulf of Mexico Dead Zone

http://www.sciencedaily.com/releases/2009/06/090618124956.htm

Large 2009 Gulf Of Mexico 'Dead Zone' Predicted

ScienceDaily (June 18, 2009) — University of Michigan aquatic ecologist Donald Scavia and his colleagues say this year's Gulf of Mexico "dead zone" could be one of the largest on record, continuing a decades-long trend that threatens the health of a half-billion-dollar fishery.
The scientists' latest forecast, released June 18, calls for a Gulf dead zone of between 7,450 and 8,456 square miles—an area about the size of New Jersey.
Most likely, this summer's Gulf dead zone will blanket about 7,980 square miles, roughly the same size as last year's zone, Scavia said. That would put the years 2009, 2008 and 2001 in a virtual tie for second place on the list of the largest Gulf dead zones.
It would also mean that the five largest Gulf dead zones on record have occurred since 2001. The biggest of these oxygen-starved, or hypoxic, regions developed in 2002 and measured 8,484 square miles.
"The growth of these dead zones is an ecological time bomb," said Scavia, a professor at the U-M School of Natural Resources and Environment and director of the U-M Graham Environmental Sustainability Institute.
"Without determined local, regional and national efforts to control them, we are putting major fisheries at risk," said Scavia, who also produces annual dead-zone forecasts for the Chesapeake Bay.
The Gulf dead zone forms each spring and summer off the Louisiana and Texas coast when oxygen levels drop too low to support most life in bottom and near-bottom waters.
The Gulf hypoxia research team is supported by the U.S. National Oceanic and Atmospheric Administration's Center for Sponsored Coastal Ocean Research and includes scientists from Louisiana State University and the Louisiana Universities Marine Consortium.
The forecast for a large 2009 Gulf hypoxic zone is based on above-normal flows in the Mississippi and Atchafalaya rivers this spring, which delivered large amounts of the nutrient nitrogen. In April and May, flows in the two rivers were 11 percent above average.
Additional flooding of the Mississippi since May could result in a dead zone that exceeds the upper limit of the forecast, the scientists said.
"The high water-volume flows, coupled with nearly triple the nitrogen concentrations in these rivers over the past 50 years from human activities, has led to a dramatic increase in the size of the dead zone," said Gene Turner, a lead forecast modeler at Louisiana State University.
Northeast of the Gulf, low water flows into the Chesapeake Bay shaped Scavia's 2009 forecast for that hypoxia zone.
The Bay's oxygen-starved zone is expected to shrink to between 0.7 and 1.8 cubic miles, with a "most likely" volume of 1.2 cubic miles—the lowest level since 2001 and third-lowest on record. The drop is largely due to a regional dry spell that lasted from January through April, Scavia said. Continued high flows in June, beyond the period used for the forecasts, suggest the actual size may be near the higher end of the forecast range.
"While it's encouraging to see that this year's Chesapeake Bay forecast calls for a significant drop in the extent of the dead zone, we must keep in mind that the anticipated reduction is due mainly to decreased precipitation and water runoff into the Bay," he said.
"The predicted 2009 dead-zone decline does not result from cutbacks in the use of nitrogen, which remains one of the key drivers of hypoxia in the Bay."
Farmland runoff containing fertilizers and livestock waste—some of it from as far away as the Corn Belt—is the main source of the nitrogen and phosphorus that cause the Gulf of Mexico dead zone.
Each year in late spring and summer, these nutrients make their way down the Mississippi River and into the Gulf, fueling explosive algae blooms there. When the algae die and sink, bottom-dwelling bacteria decompose the organic matter, consuming oxygen in the process. The result is an oxygen-starved region in bottom and near-bottom waters: the dead zone.
The same process occurs in the Chesapeake Bay, where nutrients in the Susquehanna River trigger the event. In both the Gulf and the Bay, fish, shrimp and crabs are forced to leave the hypoxic zone. Animals that cannot move perish.
The annual hypoxia forecasts helps coastal managers, policy makers, and the public better understand what causes dead zones. The models that generate the forecasts have been used to determine the nutrient-reduction targets required to reduce the size of the dead zone.
"As with weather forecasts, the Gulf forecast uses multiple models to predict the range of the expected size of the dead zone. The strong track record of these models reinforces our confidence in the link between excess nutrients from the Mississippi River and the dead zone," said Robert Magnien, director of NOAA's Center for Sponsored Coastal Ocean Research.
U.S. Geological Survey data on spring river flow and nutrient concentrations inform the computer models that produce the hypoxia forecasts.
The official size of the 2009 hypoxic zone will be announced following a NOAA-supported monitoring survey led by the Louisiana Universities Marine Consortium on July 18-26. In addition, NOAA's Southeast Area Monitoring and Assessment Program's (SEAMAP) is currently providing near real-time data on the hypoxic zone during a five-week summer fish survey in the northern Gulf of Mexico.