This page is about the oceanic phenomenon; see The Dead Zone for the novel by Stephen King. The Dead Zone is a novel by Stephen King published in 1979. ... DeFoes Robinson Crusoe, Newspaper edition published in 1719 A novel (from French nouvelle, new) is an extended fictional narrative in prose. ... Stephen Edwin King (born September 21, 1947) is a prolific American author best known for his horror novels. ...

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

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. The term could as well apply 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 kilometer, but the largest dead zone covered 70,000 square kilometers. From http://daac. ... From http://daac. ... Decline of oxygen saturation to anoxia, measured during the night in Kiel Fjord, Germany. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... This article provides extensive lists of events and significant personalities of the 1970s. ... 2004 : January - February - March - April - May - June - July - August - September - October - November - December Deaths • 08 Abu Abbas • 20 Queen Juliana • 28 Peter Ustinov • 30 Alistair Cooke More March 2004 deaths Ongoing events EU Enlargement Exploration of Mars: Rovers Haiti Rebellion Israeli-Palestinian conflict Occupation of Iraq Same-sex marriage in... Klaus Töpfer, UNEP Exec. ... Klaus Töpfer, UNEP Exec. ... 2003 is a common year starting on Wednesday of the Gregorian calendar. ...

Causes of dead zones

Nitrogen cycle

Aquatic and marine dead zones can be caused by the process of eutrophication, triggered by an excess of plant nutrients (nitrogen and phosphorus) from fertilizers, sewage, combustion emissions from vehicles, power generators, and factories. In a cascade of effects, the nutrients trigger a bloom of phytoplankton at the bottom of the marine food chain, allowing zooplankton to proliferate. As phytoplankton and zooplankton die and sink below the photic zone where photosynthesis can occur, a bloom of natural bacterial degradation exhausts the water's dissolved oxygen. Nitrogen cycle from UNEP Geo Year Book 2003, http://www. ... Nitrogen cycle from UNEP Geo Year Book 2003, http://www. ... Eutrophication is apparent as increased turbidity in the northern part of the Caspian Sea, imaged from orbit. ... Nutrients and the body A nutrient is any element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... This article is about the chemical element. ... Fertilizers are chemicals given to plants with the intention of promoting growth; they are usually applied either via the soil or by foliar spraying. ... Sewage is domestic, municipal, or industrial liquid waste products. ... A colorized automobile engine An internal combustion engine is an engine that is powered by the expansion of hot combustion products of fuel directly acting within an engine. ... Oil power plant in Iraq A power station (also power plant) is a facility for the generation of electric power. ... A red tide resulting from a dinoflagellate bloom discoloring the water on the right An algal bloom is a relatively rapid increase in the population of (usually) phytoplankton algae in an aquatic system. ... Phytoplankton shown highly magnified Phytoplankton refers to the algal or plant-like component of the plankton that drifts in the water column. ... Food chains and food webs describe the feeding relationships between species in a biotic community. ... Photomontage of plankton organisms Plankton is the aggregate community of weakly swimming but mostly drifting small organisms that inhabit the water column of the ocean, seas, and bodies of freshwater. ... The photic zone is the depth of the water, whether in a lake or an ocean, that is exposed to sufficient sunlight for photosynthesis to occur. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ...

Dead zones can also be produced by the natural event of river flooding. Large amounts of fresh water empty into the ocean forming a thick layer of fresh water atop the denser salt water, effectively forming a barrier between the ocean water and oxygen in the atmosphere. (Osterman, 2004) Look up Flood in Wiktionary, the free dictionary A flood (in Old English flod, a word common to Teutonic languages; compare German Flut, Dutch vloed from the same root as is seen in flow, float) is an overflow of water, an expanse of water submerging land, a deluge. ... For the village on the Isle of Wight, see Freshwater, Isle of Wight. ... For information on water from a sea or ocean, see sea water. ... Atmosphere may refer to: a celestial body atmosphere, e. ...

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 prevalant remains found. The periods indicated by the sediment record correspond to historic records of high river flow recorded by instruments at Vicksburg, Mississippi. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. ... Length 6,270 km Elevation of the source 450 m Average discharge Saint Louis¹: 5,500 m³/s Vicksburg²: 16,800 m³/s Baton Rouge³: 12,800 m³/s Area watershed 2,980,000 km² Origin Lake Itasca Mouth Gulf of Mexico Basin countries United States (98. ... Illinois Memorial in the Vicksburg National Military Park Vicksburg is a city located in Warren County, Mississippi. ... State nickname: Magnolia State Other U.S. States Capital Jackson Largest city Jackson Governor Haley Barbour (R) Official languages English Area 125,546 km² (32nd)  - Land 121,606 km²  - Water 3,940 km² (3%) Population (2000)  - Population 2,697,243 (31st)  - Density 23. ...

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. fishkill Baltic - image Uwe Kils GFDL File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Baltic can refer to: The Baltic Sea Council of the Baltic Sea States - an intergovernmental organization Baltic sea countries - countries with access to the Baltic Sea The term Baltic countries is sometimes used more or less synonymously for Northern Europe (Russia not included) The Baltic region (Balticum) Baltic States - the... The Gulf of Mexico is a major body of water bordered and nearly landlocked by North America. ... It has been suggested that Northern America be merged into this article or section. ...

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) Killifish are small egg laying tooth-carp fish belonging to the order Cyprinodontiformes. ... Southeastern Louisiana State University is a state-funded public university that is located in the city of Hammond, Louisiana. ... A sex organ, or primary sexual characteristic, narrowly defined, is any of those parts of the body (which are not always bodily organs according to the strict definition) which are involved in sexual reproduction and constitute the reproductive system in a complex organism; namely: Male: penis (notably the glans penis...

Another study by the University of Texas at Austin Marine Science Institute was done on the Atlantic croaker fish in Pensacola Bay, Florida. The study was of year-old croakers that live in an estuary that has summer-long hypoxic conditions. During the study, none of the fish spawned at the expected time, or later. Examination of sample fish determined that they lacked mature eggs or sperm. (Murphy, et. al., 2004) The University of Texas at Austin, often called UT or Texas, is the flagship institution of the University of Texas System. ... Genera See text. ... This article is about the inland city of Pensacola, Florida. ... State nickname: Sunshine State Other U.S. States Capital Tallahassee Largest city Jacksonville Governor Jeb Bush (R) Official languages English Area 170,451 km² (22nd)  - Land 137,374 km²  - Water 30,486 km² (17. ... Estuaries and coastal waters are among the most productive ecosystems on Earth, providing numerous ecological, economic, cultural, and aesthetic benefits and services. ...

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. A hormone (from Greek horman - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ...

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 mineralization and recycling that occurs among benthic life-forms is stifled. In marine geology and biology, benthos are the organisms and habitats of the sea floor; in freshwater biology they are the organisms and habitats of the bottoms of lakes, rivers, and creeks. ...

Locations of dead zones

Dead Zones around the World

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. Map of dead zones from UNEP Geo Year Book 2003, http://www. ... Map of dead zones from UNEP Geo Year Book 2003, http://www. ... Chesapeake Bay - Landsat photo The Chesapeake Bay is the largest estuary in the United States. ... Simplified diagram A strait is a narrow channel of water that connects two larger bodies of water, and thus lies between two land masses. ... The Baltic Sea The Kattegat, or Kattegatt, is a bay of the North Sea and a continuation of the Skagerrak, bounded by Denmark and Sweden. ... The Baltic Sea is located in Northern Europe, bounded by the Scandinavian Peninsula, the mainlands of Northern Europe, Eastern Europe, Central Europe, and the Danish islands. ... The Adriatic Sea is an arm of the Mediterranean Sea separating the Apennine peninsula (Italy) from the Balkan peninsula, and the system of the Apennine Mountains from that of the Dinaric Alps and adjacent ranges. ...

Currently the most notorious dead zone is a 20,000 square kilometer 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, affecting important shrimp fishing grounds. The Gulf of Mexico is a major body of water bordered and nearly landlocked by North America. ... Length 6,270 km Elevation of the source 450 m Average discharge Saint Louis¹: 5,500 m³/s Vicksburg²: 16,800 m³/s Baton Rouge³: 12,800 m³/s Area watershed 2,980,000 km² Origin Lake Itasca Mouth Gulf of Mexico Basin countries United States (98. ... In agriculture, agribusiness is a generic term that refers to the various businesses involved in the food production chain, including farming, seed, agrichemicals, farm machinery, wholesaling, processing, distribution, and retail sales. ...

Other marine dead zones have appeared in coastal waters of South America, China, Japan, southeast Australia, and even in the waters of New Zealand, which have a reputation for being some of the planet's most pristine near-coastal marine environments.

Reversal of dead zones

Dead zones are not irreversible. 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. Map of the Black Sea. ... Pre-1989 division between the West (grey) and Eastern Bloc (orange) superimposed on current national boundaries: Russia (dark orange), other countries of the former USSR (medium orange) and other former communist regimes (light orange). ... Historical lands and provinces in Central Europe Central Europe is the region lying between the variously and vaguely defined areas of Eastern and Western Europe. ...

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. From 1985-2000, 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. The North Sea is a sea of the Atlantic Ocean, located between the coasts of Norway and Denmark in the east, the coast of the British Isles in the west, and the German, Dutch, Belgian and French coasts in the south. ... The Rhine canyon (Ruinaulta) in Graubünden in Switzerland Length 1,320 km Elevation of the source Vorderrhein: approx. ...

References

• 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].
• 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.
• Murphy, C. . . . P. Thomas, et al. 2004. Modeling the effects of multiple anthropogenic and environmental stressors on Atlantic croaker populations using nested simulation models and laboratory data. Fourth SETAC World Congress, 25th Annual Meeting in North America. Nov. 14-18. Portland, Ore. Abstract.
• 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.

External links

• UN Geo Yearbook 2003 report on nitrogen and dead zones
• MSNBC report on dead zones, March 29, 2004
• NASA on dead zones (Satellite pictures)
• Gulf of Mexico Dead Zone - multimedia