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Smaller Than Expected, But Severe, Dead Zone in Gulf of Mexico

July 27, 2009

Deadzone on July 27, 2009.

Deadzone on July 27, 2009.

High resolution (Credit: LUMCON)

NOAA-supported scientists, led by Nancy Rabalais, Ph.D. from the Louisiana Universities Marine Consortium, found the size of this year’s Gulf of Mexico dead zone to be smaller than forecasted, measuring 3,000 square miles. However the dead zone, which is usually limited to water just above the sea floor, was severe where it did occur, extending closer to the water surface than in most years.

Earlier this summer, NOAA-sponsored forecast models developed by R. Eugene Turner, Ph. D. of Louisiana State University and Donald Scavia, Ph.D. of the University of Michigan, predicted a larger than normal dead zone area of between 7,450 – 8,456 square miles. The forecast was driven primarily by the high nitrate loads and high freshwater flows from the Mississippi and Atchafalaya rivers in spring 2009 as measured by the U.S. Geological Survey.

Rabalais believes the smaller than expected dead zone is due to unusual weather patterns that re-oxygenated the waters, among other factors.

“The winds and waves were high in the area to the west of the Atchafalaya River delta and likely mixed oxygen into these shallower waters prior to the cruise, thus reducing the area of the zone in that region,” said Rabalais. “The variability we see within each summer highlights the continuing need for multiple surveys to measure the size of the dead zone in a more systematic fashion.”

“The results of the 2009 cruise at first glance are hopeful, but the smaller than expected area of hypoxia appears to be related to short-term weather patterns before measurements were taken, not a reduction in the underlying cause, excessive nutrient runoff,” said Robert Magnien, Ph.D., director of NOAA’s Center for Sponsored Coastal Ocean Research. “The smaller area measured by this one cruise, therefore, does not represent a trend and in no way diminishes the need for a harder look at efforts to reduce nutrient runoff.”

The average size of the dead zone over the past five years, including this cruise, is now 6,000 square miles. The interagency Gulf of Mexico/Mississippi River Watershed Nutrient Task Force has a goal to reduce or make significant progress toward reducing this dead zone average to 2,000 square miles or less by 2015. The Task Force uses a five year average due to relatively high interannual variability.

The dead zone is fueled by nutrient runoff, principally from agricultural activity, which stimulates an overgrowth of algae that sinks, decomposes, and consumes most of the life-giving oxygen supply in the water. The Gulf of Mexico dead zone is of particular concern because it threatens valuable commercial and recreational Gulf fisheries that generate about $2.8 billion annually.

The models used to forecast the area of the dead zone are constructed for understanding the important underlying causes to inform long-term management decisions, but they do not include short-term variability due to weather patterns.

Prior to the Louisiana consortium cruise, NOAA’s Southeast Monitoring and Assessment Program found a similar sized dead zone during its annual five-week summer fish survey.

NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.

http://www.noaanews.noaa.gov/stories2009/20090727_deadzone.html

***

**

The size of dead zones fluctuates throughout any
given year with the largest dead zones appearing in
summer months. The hypoxic area in the Gulf of
Mexico has more than doubled in size since the late
1980s. Initial forecasts for the size of the 2009 dead
zone in the Gulf estimated it to be around 7,500 -
8,500 square miles, however scientists found the dead
zone to be 3,000 square miles.
The result appears hopeful as on average the size
of the dead zone is estimated to be 6,000 square
miles. However this smaller than expected result is
believed to be related to short-term weather patterns
before measurements were taken and not a reduction
in excessive nutrient runoff. The largest dead zone on
record occurred in 2002, measuring 8,484 square miles.

http://www.noaanews.noaa.gov/stories2009/pdfs/new%20fact%20sheet%20dead%20zones_final.pdf

***

LUMCON Hypoxia Site

What is hypoxia?

Hypoxia, or low oxygen, is an environmental phenomenon where the concentration of dissolved oxygen in the water column decreases to a level that can no longer support living aquatic organisms. Hypoxic areas, or “Dead Zones,” have increased in duration and frequency across our planet’s oceans since first being noted in the 1970s.

The largest hypoxic zone currently affecting the United States, and the second largest hypoxic zone worldwide, is the northern Gulf of Mexico adjacent to the Mississippi River.

http://www.gulfhypoxia.net/

What is the Gulf of Mexico dead zone?
Tue, Jul 28 2009 at 9:30 AM EST
From red tides in the Atlantic to a furry blob in Alaska, seaweed seems to be invading the U.S. from all sides. But the country’s worst algae onslaught, even after a quiet summer, still lingers at the mouth of the Mississippi.

**

[from recent press releases on the above site -]

Low oxygen levels have returned to the Gulf of Mexico along the coast of Texas

By Patrique Ludan, The BATALLION ONLINE, College Station, Texas
7/16/09
Low oxygen levels have returned to the Gulf of Mexico along the coast of Texas, indicating the return of a dead zone, according to Texas A&M researchers.
Steve Dimarco, associate professor of oceanography, said that a dead zone is an area in an ocean, lake, bay or estuary, where hypoxia, or an oxygen concentration of less than 2 milligrams per liter, is found.

In 2007, a research group, including Dimarco, found a dead zone off the coast of Freeport, Texas.

The newly detected dead zone is off the coast of south Galveston. The hypoxia contained within the water is already below levels that are considered harmful to marine life.

The researchers used a water-quality monitoring system to detect the dead zone. The system provides hourly updates on water salinity, temperature, oxygen and other data.

The current research is funded by the National Oceanic and Atmospheric Administration, NOAA, Center for Sponsored Coastal Ocean Research, CSCOR, Dimarco said.

There are an estimated 200 dead zones located throughout the world as of 2006, according to a 2008 UN Environmental Program report entitled “In Dead Water.”

One of the largest dead zones predicted this year is off the coast of Louisiana, separate from the Texas dead zone, according to NOAA-CSCOR. The Louisiana dead zone is predicted to measure around 7,450 to 8,456 square miles, or an area roughly the size of New Jersey.

The largest dead zone recorded in the Gulf occurred in 2002 off the coast of Louisiana. Currently NOAA has not estimated the size of the dead zone near the coast of Texas.

The first observations of a dead zone near the Texas coast were made in 1970 by Don Harper, a professor at Texas A&M University-Galveston.

“Those observations did not allow us to determine how long it lasted, how big of an area it covered, or what definitively caused it,” Dimarco said.

The observations made currently are designed to show how frequently hypoxia occurs near coastal Galveston.

“This is important because it will provide valuable information for coastal managers to make decisions concerning coastal fisheries and other living resources,” Dimarco said. “In a broader sense, it will also provide extremely valuable data to determine the causes of coastal hypoxia and potentially to model its effects on marine organisms.”

Dead zones are caused by nutrient runoff, which comes from different types of agricultural activity. This stimulates an overgrowth of algae, which then sinks, decomposes and finally consumes most of the life-giving oxygen supply in the water.

Other causes of these dead zones come from climate change, or in other words global warming, according to a United Nations report.

“There is general consensus that different climate change scenarios could affect the dead zone of the northern Gulf of Mexico (which includes both Texas and Louisiana),” Dimarco said. “More rainfall could make it worse, changing wind patterns could make it worse or better depending on the character of the change; a warming climate could make it occur more frequently.”

Researchers are not certain how to reverse the process of dead zones.

“There is likely a human component, but there is good evidence that this is a natural condition which has been going on for a long time (more than
1,000 years off of Louisiana),” said Dimarco.

Right now the Texas Sea Grant College Program is reviewing a proposal by Dimarco and his team for additional funding, said Texas Sea Grant College Program director Robert Stickney.

“His work is extremely important and we are very supportive of it,” Stickney said.

The Texas Sea Grant College Program partially funded Dimarco’s research in 2007.

http://media.www.thebatt.com/media/storage/paper657/news/2009/07/16/News/Dead-Zone.Returns.To.Gulf.Of.Mexico-3751912-page2.shtml

http://www.gulfhypoxia.net/News/default.asp?XMLFilename=200907172335.xml

***

******

http://www.sciencedaily.com/releases/2008/08/080814154325.htm

A dead zone also underlies much of the main-stem of Chesapeake Bay, each summer occupying about 40% of its area and up to 5% of its volume. The above map shows measurements of hypoxia in the bay in 2003.

Study Shows Continued Spread Of ‘Dead Zones’; Lack Of Oxygen Now A Key Stressor On Marine Ecosystems

ScienceDaily (Aug. 15, 2008) — A global study led by Professor Robert Diaz of the Virginia Institute of Marine Science, College of William and Mary, shows that the number of “dead zones”—areas of seafloor with too little oxygen for most marine life—has increased by a third between 1995 and 2007.

Diaz and collaborator Rutger Rosenberg of the University of Gothenburg in Sweden say that dead zones are now “the key stressor on marine ecosystems” and “rank with over-fishing, habitat loss, and harmful algal blooms as global environmental problems.”

[etc.]

The study, which appears in the August 15 issue of the journal Science, tallies 405 dead zones in coastal waters worldwide, affecting an area of 95,000 square miles, about the size of New Zealand. The largest dead zone in the U.S., at the mouth of the Mississippi, covers more than 8,500 square miles, roughly the size of New Jersey.

Diaz began studying dead zones in the mid-1980s after seeing their effect on bottom life in a tributary of Chesapeake Bay near Baltimore. His first review of dead zones in 1995 counted 305 worldwide. That was up from his count of 162 in the 1980s, 87 in the 1970s, and 49 in the 1960s. He first found scientific reports of dead zones in the 1910s, when there were 4. Worldwide, the number of dead zones has approximately doubled each decade since the 1960s.

[ . . . ]

Adapted from materials provided by Virginia Institute of Marine Science.

http://www.sciencedaily.com/releases/2008/08/080814154325.htm

Virginia Institute of Marine Science (2008, August 15). Study Shows Continued Spread Of ‘Dead Zones’; Lack Of Oxygen Now A Key Stressor On Marine Ecosystems. ScienceDaily. Retrieved August 7, 2009, from http://www.sciencedaily.com­ /releases/2008/08/080814154325.htm

***

09.13.08

Oceans dying fast

Posted in Daily life, Environment, Food, Science tagged at 1:46 pm by LeisureGuy

Ocean dead zones

Ocean dead zones

Maybe we’ll kill off ALL the fish. The above image is from this article, which has more information.

[from -]

***

Ocean Dead Zones Likely To Expand: Increasing Carbon Dioxide And Decreasing Oxygen Make It Harder For Deep-sea Animals To Breath (Apr. 18, 2009) — Low-oxygen “dead zones” in the ocean could expand significantly over the next century, according to marine chemists. These predictions are based on the fact that, as more and more carbon dioxide …  > read more

Nutrient Pollution Chokes Marine And Freshwater Ecosystems (Mar. 5, 2009) — Protecting drinking water and preventing harmful coastal “dead zones,” as well as eutrophication in many lakes, will require reducing both nitrogen and phosphorus …  > read more
Baltic States Failing To Protect Most Damaged Sea (Sep. 3, 2008) — Nine Baltic sea states all scored failing grades in an annual WWF evaluation of their performance in protecting and restoring the world’s most damaged …  > read more
***

http://www.sciencedaily.com/releases/2008/08/080814154325.htm

[also - ]

Scientists study huge plastic patch in Pacific

***

“Dead Zone”

Posted by The College of Science at OSU on May 2, 2008

From Smithsonian Magazine, April 2008:

Gasping for Breath
An ocean “dead zone” has been discovered off the Pacific Northwest. The water has so little oxygen that it “kills any marine animals that cannot swim or scuttle away,” says Jane Lubchenco of Oregon State University. She and her colleagues analyzed 60 years of data and found that oxygen levels dropped in 2002. Most of the hundreds of dead zones worldwide are caused by pollution. But this one was caused by winds and currents that disrupted the ecosystem and fueled oxygen-depleting bacteria.

Visit Jane’s webpage here: http://lucile.science.oregonstate.edu/lubchenco/

http://sciencebreakthroughsatosu.wordpress.com/2008/05/02/dead-zone/

  • Welcome to Breakthroughs

    Hello! Welcome to Breakthroughs, a site devoted to sharing with you the latest, greatest advancements from the College of Science at Oregon State University. From breakthroughs in research to transformational philanthropy to interesting tidbits from the daily life of the College, we’ll post frequently to keep you up-to-date. Please visit often and absolutely let us know what you might like to learn more about. Enjoy, and of course, GO BEAVS!

***

SCIENCE FOCUS: DEAD ZONES

Creeping Dead Zones

Sediment laden water meets blue ocean

This is not the title of a sequel to a Stephen King novel. “Dead zones” in this context are areas where the bottom water (the water at the sea floor) is anoxic — meaning that it has very low (or completely zero) concentrations of dissolved oxygen. These dead zones are occurring in many areas along the coasts of major continents, and they are spreading over larger areas of the sea floor. Because very few organisms can tolerate the lack of oxygen in these areas, they can destroy the habitat in which numerous organisms make their home.

The cause of anoxic bottom waters is fairly simple: the organic matter produced by phytoplankton at the surface of the ocean (in the euphotic zone) sinks to the bottom (the benthic zone),where it is subject to breakdown by the action of bacteria, a process known as bacterial respiration. The problem is, while phytoplankton use carbon dioxide and produce oxygen during photosynthesis, bacteria use oxygen and give off carbon dioxide during respiration. The oxygen used by bacteria is the oxygen dissolved in the water, and that’s the same oxygen that all of the other oxygen-respiring animals on the bottom (crabs, clams, shrimp, and a host of mud-loving creatures) and swimming in the water (zooplankton, fish) require for life to continue.

The “creeping dead zones” are areas in the ocean where it appears that phytoplankton productivity has been enhanced, or natural water flow has been restricted, leading to increasing bottom water anoxia. If phytoplankton productivity is enhanced, more organic matter is produced, more organic matter sinks to the bottom and is respired by bacteria, and thus more oxygen is consumed. If water flow is restricted, the natural refreshing flow of oxic waters (water with normal dissolved oxygen concentrations) is reduced, so that the remaining oxygen is depleted faster.

Many of the areas where increasing bottom water anoxia has recently been observed are near the mouths of major river systems. While the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) can’t see the bottom of the ocean, it can see the surface, where sediments from rivers mix with ocean waters. The images shown here are SeaWiFS observations of the Mississippi River delta, the Yangtze River mouth in China (The Yangtze River mouth is not currently identified as an area with an associated dead zone, but such conditions could develop there in the future), and the Pearl River mouth in China, near Hong Kong.

River Deltas

SeaWiFS can also observe areas where water flow is restricted, such as the Baltic Sea in Europe. The image on the left features Denmark after strong storms caused flooding and increased sediment suspension in the Baltic. On the right is an overview of the Baltic Sea, including a plankton bloom in the Skagerrak just north of Denmark.

Baltic Sea

The apparent cause of the creeping dead zones is agriculture, specifically fertilizer. While fertilizer is necessary to foster bumper agricultural crops, it also runs off the fields into the streams and rivers of a watershed. When the fertilizer reaches the ocean, it just becomes more nutrients for the phytoplankton, so they do what they do best: they grow and multiply. Which leads to more organic matter reaching the bottom, more bacterial respiration, and more anoxic bottom water.

These effects can be magnified by catastrophe. When the heavy rains of Hurricane Floyd caused extensive flooding in North Carolina in September 1999, the heavy load of nutrients (from dead animals, flooded animal waste ponds, and numerous other sources) reached the sounds that lie between the coast and the Outer Banks, oxygen levels in the water plummeted. The picture at the top of the page shows the heavy load of sediments flowing into Pamlico Sound. SeaWiFS captured a remarkable image on September 23, 1999, when the sediment-laden water was carried into the Gulf Stream. In this image, note the turbidity in the sounds and the deep brown color at the river mouths. In some areas of the Neuse River, the water actually turned red.

In Europe, the flow of water into and out of the Baltic Sea is naturally restricted by the islands and narrow channels around Denmark. Thus, any increase in nutrients which augments biological productivity can be a problem — and that’s what is being observed in the Baltic. The situation at the mouths of major rivers is similar: the area covered by anoxic bottom water appears to be increasing every year.

Dr. Robert Diaz of the Virginia Institute of Marine Science (VIMS) has created a map of dead zones throughout the world (a version of this map also appeared in the March 2000 issue of Discover magazine). Diaz estimates that the number of such sites will double within a decade.

Dead Zones Map

There is another interesting aspect to zones of anoxia—not all areas with anoxic bottom water are caused by pollution. The largest “dead zone” on the planet is the entire Black Sea below a depth of about 150 meters. Due to the fact that the exchange of water in the Black Sea with the Mediterranean Sea is limited to the flow through the narrow Bosporus, all of the mixing of freshwater and seawater takes place in the upper 150 meters, because the freshwater entering from rivers is less dense than seawater.

Black Sea Diagram
Graphic adapted from Black Sea Sediments by Holger Lueschen.

Below the pycnocline (a density boundary where the water density increases abruptly), the Black Sea water column is entirely anoxic, down to the bottom 2000 meters below. SeaWiFS can’t see that deep, either, but it can get a good image of the Black Sea on a clear day. Note the Bosporus in the lower-left corner of the image, and the delta of the Danube River on the western coast of the sea.

Black Sea

Recently, geologists Walter Pitman and William Ryan suggested that the Black Sea had been a freshwater lake at one time, and it became an anoxic marine basin fairly recently. Around 5600 B.C., as sea levels rose due to glacial melting, a flood of seawater broke through the Bosporus and inundated the Black Sea basin. The influx of Mediterranean seawater raised the level of the lake about 150 meters, and created the density difference that prevented mixing. Once the Black Sea was filled, the development of anoxia would have happened relatively quickly. One indication of the event is the age of freshwater mussels that died as oxygen concentrations fell. The anoxic bottom waters also hold the promise of preserving ancient wooden vessels, and even buildings in coastal communities that existed before the flood.

(NOTE, November 2003: As scientific examination of this hypothesis has progressed since it was first proposed by Ryan and Pitman, the dramatic rapid infilling scenario can no longer be supported. See the Black Sea section of the “Associated URLs” below for a recent report on the status of understanding the paleohistory of the Black Sea and surrounding regions. There may have been a much more powerful flood earlier in time, approximately 15-16,000 years ago, resulting from the overflow of the Caspian Sea into the ancient Black Sea basin. The Ryan and Pitman event, while still appearing to have occurred, did not involve as much water or as large a rise in the level of the Black Sea as first proposed.)

Dr. Robert Ballard, famed as the discoverer of the wreck of the Titanic , searched the Black Sea in 1999 and found indications of the ancient shoreline of the freshwater lake. In 2000, Ballard found evidence of ancient settlements on the underwater shore of this ancient lake, well-preserved due to the anoxic conditions, which preserve organic matter well. (Ryan and Pitman proposed that the sudden filling of the Black Sea was the basis for the Noah’s Flood story in the Bible, but we won’t get into that debate here.)

Another naturally occurring anoxic basin is the Cariaco Basin, near the coast of Venezuela. Because the sediments in anoxic basins are also without oxygen, they preserve organic matter which is normally consumed by bacteria. Thus, the Cariaco Trench is a natural sediment trap, recording how much organic matter is produced in the overlying waters year after year. Researchers are using SeaWiFS data to observe the productivity cycles in the surface water and then correlating these observations with the record preserved in the organic-rich botto sediments.

SeaWiFS image of Vancouver Island, featuring Saanich InletFinally, one other anoxic zone. The Saanich Inlet on Vancouver Island, Canada, has a “sill” near the mouth of the inlet, about 70 meters deep, which restricts the exchange of water from the Pacific Ocean and the bottom of the inlet. For the same reasons given above, the bottom waters of the Saanich below 100 meters are also anoxic, and sediments from the Saanich have been studied to provide information about changing environmental conditions on the western coast of Canada. The Saanich sediments are particularly valuable because the have annual layers (varves). The study of the Saanich sediments can be compared to tree rings from trees over 12,000 years old that were found in a nearby lake.

Associated URLs

SeaWiFS

Mississippi River Dead Zone

Saanich Inlet

Cariaco Basin

National Oceanic and Atmospheric Administration

Black Sea

[ From - ]

http://disc.sci.gsfc.nasa.gov/oceancolor/additional/science-focus/ocean-color/dead_zones.shtml

***

Dead zone (ecology)

From Wikipedia, the free encyclopedia

Dead zones are often caused by the decay of algae during algal blooms, like this one off the coast of La Jolla, San Diego, California.

Dead zones are hypoxic (low-oxygen) areas in the world’s oceans, the observed incidences of which have been increasing since oceanographers began noting them in the 1970s. These occur near inhabited coastlines, where aquatic life is most concentrated. (The vast middle portions of the oceans which naturally have little life are not considered “dead zones”.) The term can also be applied to the identical phenomenon in large lakes.

In March 2004, when the recently-established UN Environment Programme published its first Global Environment Outlook Year Book (GEO Year Book 2003) it reported 146 dead zones in the world oceans where marine life could not be supported due to depleted oxygen levels. Some of these were as small as a square kilometre (0.4 mi²), but the largest dead zone covered 70,000 square kilometres (27,000 mi²). A 2008 study counted 405 dead zones worldwide.[1][2]

Contents

// <![CDATA[
//

Causes of dead zones

Aquatic and marine dead zones can be caused by an increase in chemical nutrients in the water, known as eutrophication. Eutrophication leads to harmful algal blooms (HABs). When algal blooms die off, oxygen is used to decompose the algae which creates hypoxic conditions. Chemical fertilizer is considered the prime cause of dead zones around the world. Runoff from sewage, urban land use, and fertilizers can also contribute to eutrophication. [3]

The Pacific Coast of the United States has a 1120 square mile (2900 km²) dead zone caused by stronger winds that many associate with global warming. [4]. This dead zone has recurred between June and September every year since 2002. [4]

Additionally, natural oceanographic phenomena can cause deoxygenation of parts of the water column. For example, enclosed bodies of water such as fjords or the Black Sea have shallow sills at their entrances causing water to be stagnant there for a long time. The eastern tropical Pacific Ocean and Northern Indian Ocean have lowered oxygen concentrations which are thought to be in regions where there is minimal circulation to replace the oxygen that is consumed (e.g. Pickard & Emery 1982, p 47).[5]

Remains of organisms found within sediment layers near the mouth of the Mississippi River indicate four hypoxic events before the advent of artificial fertilizer. In these sediment layers, anoxia-tolerant species are the most prevalent remains found. The periods indicated by the sediment record correspond to historic records of high river flow recorded by instruments at Vicksburg, Mississippi.

Effects of dead zones

Underwater video frame of the sea floor in the Western Baltic covered with dead or dying crabs, fish and clams killed by oxygen depletion

Low oxygen levels recorded along the Gulf Coast of North America have led to reproductive problems in fish involving decreased size of reproductive organs, low egg counts and lack of spawning.

In a study of the Gulf killifish by the Southeastern Louisiana University done in three bays along the Gulf Coast, fish living in bays where the oxygen levels in the water dropped to 1 to 2 parts per million (ppm) for 3 or more hours per day were found to have smaller reproductive organs. The male gonads were 34% to 50% as large as males of similar size in bays where the oxygen levels were normal (6 to 8 ppm). Females were found to have ovaries that were half as large as those in normal oxygen levels. The number of eggs in females living in hypoxic waters were only one-seventh the number of eggs in fish living in normal oxygen levels. (Landry, et al., 2004)

Fish raised in laboratory-created hypoxic conditions showed extremely low sex-hormone concentrations and increased elevation of activity in two genes triggered by the hypoxia-inductile factor (HIF) protein. Under hypoxic conditions, HIF pairs with another protein, ARNT. The two then bind to DNA in cells, activating genes in those cells.

Under normal oxygen conditions, ARNT combines with estrogen to activate genes. Hypoxic cells in a test tube didn’t react to estrogen placed in the tube. HIF appears to render ARNT unavailable to interact with estrogen, providing a mechanism by which hypoxic conditions alter reproduction in fish. (Johanning, et al., 2004)

It might be expected that fish would flee this potential suffocation, but they are often quickly rendered unconscious and doomed. Slow moving bottom-dwelling creatures like clams, lobsters and oysters are unable to escape. All colonial animals are extinguished. The normal re-mineralization and recycling that occurs among benthic life-forms is stifled.

Locations of dead zones

In the 1970s, marine dead zones were first noted in areas where intensive economic use stimulated “first-world” scientific scrutiny: in the U.S. East Coast’s Chesapeake Bay, in Scandinavia’s strait called the Kattegat, which is the mouth of the Baltic Sea and in other important Baltic Sea fishing grounds, in the Black Sea, (which may have been anoxic in its deepest levels for millennia, however) and in the northern Adriatic.

Other marine dead zones have apparently appeared in coastal waters of South America, China, Japan, and southeast Australia. A 2008 study counted 405 dead zones worldwide.[1][2][6]

Oregon

Sediment from the Mississippi River carries fertilizer to the Gulf of Mexico

Off the coast of Cape Perpetua, Oregon, there is also a dead zone with a 2006 reported size of 300 square miles (780 km²).[7] This dead zone only exists during the summer, perhaps due to wind patterns.

Gulf of Mexico

Currently the most notorious dead zone is a 22,126 square kilometre (8,543 mi²) region in the Gulf of Mexico, where the Mississippi River dumps high-nutrient runoff from its vast drainage basin, which includes the heart of U.S. agribusiness, the Midwest. The drainage of these nutrients are affecting important shrimp fishing grounds. This is equivalent to a dead zone the size of New Jersey. A dead zone off the coast of Texas where the Brazos River empties into the Gulf was also discovered in July 2007.[8]

Reversal of dead zones -

Dead zones are reversible.

The Black Sea dead zone, previously the largest dead zone in the world, largely disappeared between 1991 and 2001 after fertilizers became too costly to use following the collapse of the Soviet Union and the demise of centrally planned economies in Eastern and Central Europe. Fishing has again become a major economic activity in the region.[9]

While the Black Sea “cleanup” was largely unintentional and involved a drop in hard-to-control fertilizer usage, the U.N. has advocated other cleanups by reducing large industrial emissions.[9] From 1985 to 2000, the North Sea dead zone had nitrogen reduced by 37% when policy efforts by countries on the Rhine River reduced sewage and industrial emissions of nitrogen into the water. Other cleanups have taken place along the Hudson River[10] and San Francisco Bay.[1]

The chemical Aluminium sulfate can be used to reduce phosphates in water.[1]

Notes

  1. ^ a b c http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/08/15/MNLD12ADSN.DTL
  2. ^ a b http://dx.doi.org/10.1126/science.1156401
  3. ^ http://www.msnbc.msn.com/id/22301669 Corn boom could expand ‘dead zone’ in Gulf
  4. ^ a b http://www.latimes.com/news/local/la-me-deadzone15feb15,0,3979313.story Dead zones off Oregon and Washington likely tied to global warming, study says
  5. ^ http://www.nodc.noaa.gov/OC5/WOA01F/oxsearch.html
  6. ^ http://www.epa.gov/msbasin/pdf/diaz_data.pdf
  7. ^ Wired News – AP News
  8. ^ Bloomberg.com: Exclusive
  9. ^ a b Mee, Laurence (November 2006). “Reviving Dead Zones”. Scientific American.
  10. ^ ‘Dead Zones’ Multiplying In World’s Oceans by John Nielsen. 15 Aug 2008, Morning Edition, NPR.

References

  • Diaz, R.J., and Rosenberg, R. 2008. Spreading dead zones and consequences for marine ecosystems. Science 321(5891): 926-929. Abstract
  • Osterman, L.E., et al. 2004. Reconstructing an 180-yr record of natural and anthropogenic induced hypoxia from the sediments of the Louisiana Continental Shelf. Geological Society of America meeting. Nov. 7-10. Denver. http://gsa.confex.com/gsa/2004AM/finalprogram/abstract_75830.htm Abstract.
  • Pickard, G.L. and Emery, W.J. 1982. Description Physical Oceanography: An Introduction. Pergamon Press, Oxford, 249 pp.
  • Landry, C.A., S. Manning, and A.O. Cheek. 2004. Hypoxia suppresses reproduction in Gulf killifish, Fundulus grandis. e.hormone 2004 conference. Oct. 27-30. New Orleans.
  • Johanning, K., et al. 2004. Assessment of molecular interaction between low oxygen and estrogen in fish cell culture. Fourth SETAC World Congress, 25th Annual Meeting in North America. Nov. 14-18. Portland, Ore. Abstract.
  • Taylor, F.J., N.J. Taylor, J.R. Walsby 1985. A bloom of planktonic diatom Ceratulina pelagica off the coastal northeastern New Zealand in 1983, and its contribution to an associated mortality of fish and benthic fauna. Intertional Revue ges. Hydrobiol. 70: 773-795.
  • Morrisey, D.J. 2000. Predicting impacts and recovery of marine farm sites in Stewart Island New Zealand, from the Findlay-Watling model. Aquaculture 185: 257-271.

Further reading

External links

[From Wikipedia Entry]

http://en.wikipedia.org/wiki/Dead_zone_(ecology)

***

Flotsametrics and the Floating World

From Wikipedia, the free encyclopedia

Jump to: navigation, search

Flotsametrics and the Floating World: How One Man’s Obsession with Runaway Sneakers and Rubber Ducks Revolutionized Ocean Science is a 2009 book by Curtis Ebbesmeyer and Eric Scigliano. Ebbesmeyer and his team of volunteers used flotsam to study oceanic currents.

External links

http://en.wikipedia.org/wiki/Flotsametrics_and_the_Floating_World

***

Toxics Release Inventory

From Wikipedia, the free encyclopedia

Jump to: navigation, search

TRI-ME, the TRI computer reporting program

The Toxics Release Inventory (TRI) is a publicly available database from the EPA that contains information on toxic chemical releases and other waste management activities reported annually by certain covered industry groups as well as federal facilities. This inventory was first proposed in a 1985 New York Times op-ed piece[1] written by David Sarokin and Warren Muir, researchers for an environmental group, INFORM. TRI was established under the Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA), and later expanded by the Pollution Prevention Act of 1990. The law grew out of concern surrounding Union Carbide’s releases of toxic gases in the 1984 Bhopal disaster and a smaller 1985 release in Institute, West Virginia[2]

Each year, companies across a wide range of industries (including chemical, mining, paper, oil and gas industries) that produce more than 25,000 pounds or handle more than 10,000 pounds of a listed toxic chemical must report it to the TRI. The TRI threshold was initially set at 75,000 pounds annually. If the company treats, recycles, disposes, or releases more than 500 pounds of that chemical into the environment (as opposed to just handling it), then they must provide a detailed inventory of that chemical’s inventory.

Proposed changes in late 2005 would lower the reporting standards for TRI. Several state attorney generals wrote the EPA asking that the standard not be altered. This move came under fire from Eliot Spitzer who said “”Public disclosure has proven to be a strong incentive for polluters to reduce their use of toxic chemicals, this move by EPA appears to be yet another poorly considered notion to appease a few polluting constituents at the expense of a valuable program.” [3] EPA originally proposed to reduce the required reporting frequency from every year to every other year. This drew intense criticism, and the idea was dropped.

However, the EPA went forward with another part of the plan that initially did not receive much attention. Companies were previously required to disclose any release over 2000 pounds (907 kg) on a more detailed “Form R” rather than the less detailed “Form A”. With the new regulations, the minimum reporting requirements for Form R have been increased to 5000 pounds (2268 kg), thus reducing the amount of information available. Although this move was widely criticized by the public as well as many officials, EPA went ahead with the new rule anyway.[4] EPA claimed that the comments submitted opposed to the Form R requirements were invalid because nearly all the people who had commented did so on both the change in reporting frequency as well as the minimum amounts required for Form R.

[edit] Accessing TRI data

The data in the Toxic Release Inventory is available to the public, but accessing has until recently been a difficult task. In recent years, the EPA and several other organizations has made the task much easier.

Mapping Systems

In 2007, three organizations released tools for mapping the TRI data to particular locations. These tools also allow the user to view some of the information in the database.

MapEcos, A Map of Industrial Environmental Performance

  • MapEcos.org is a browser-based tool. It allows users to access an interactive map of the US showing the most recent TRI data. The map can be searched for locations of interest. At lower zoom levels, it allows the user to get information on pollution from particular facilities. This site was created by faculty and students at Dartmouth College, Harvard Business School, and Duke University.[5]
  • The Commission for Environmental Cooperation has created a downloadable File for Google Earth which shows all of the most recent reports to the TRI database. It also includes locations from the equivalent Canadian and Mexican pollution inventory. The system currently only maps the locations and links to data at the national registries.[6]
  • DotGovWatch offers a simple browser-based map of TRI data. The map can be searched by city, address, and each facility’s detailed emissions are available.
  • TRI.NET is a new application developed by EPA that supports complex adhoc queries of TRI data. TRI.NET maps facilities using Google Maps, Google Earth, or Virtual Earth. Additional data layers allow TRI data to be analyzed with respect to other factors such as Environmental Justice, Chemical Toxicity, and Tribal and U.S. Mexico Border geographies. Uses powerful drill-downs and advanced trends to spot trends and hot spots. [7]

Public Portals

  • Scorecard.org For those seeking detailed information, the easiest access to the data is at scorecard.org. This site also provides information about a variety of other pollution issues, but it has not been updated since 2002. This site was created by a team at Environmental Defense. It is now run by the Green Media Tool Shed.

Research Oriented Portals

  • RTKnet.org Run by an OMB watch, this site provides access to current to a variety of EPA data, including data for the TRI. Queries allow users to download files with the raw data.
  • The EPA also provides access to the raw data through their Envirofacts site. As with RTK net, queries to the underlying relational database produce downloadable text documents.

[edit] See also

[edit] References

  1. ^ Too Little Toxic Waste Data, New York Times, Oct 7, 1985, pg A31
  2. ^ What is the Toxics Release Inventory (TRI) Program
  3. ^ Waste News
  4. ^ EPA Finalizes Rules for Toxics Release Inventory – January 9, 2007 Vol. 8, No. 1 – OMB Watch
  5. ^ Mapping out the environment – CNN.com
  6. ^ GIS News:Google Earth layer helps mapping industrial pollutants
  7. ^ Find toxic wastelands via Google Earth | CNET News.com

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