Encyclopedia of Global Resources part 29 pptx

Most of the remaining copper is alloyed with other metals to make bronze with tin, brass with zinc, and nickel silver with zinc and nickel, not silver.. Most of the copper mined is taken

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geared toward improving the water productivity in

river basins The emphasis of the program is to create

synergies and partnerships among the stakeholders in

ways that are pro-poor, gender equitable, and

envi-ronmentally sustainable

Since the 1970’s, climate change has been a

re-search area of interest to CGIAR scientists They have

been working on the effects of climate change on

nat-ural resources, including water resources, and

devel-oping crop varieties that can continue to provide the

needed food to an ever-growing world population

The scientists have also been active in identifying

poli-cies and new approaches for communities to deal with

climate change and its consequences All these years

of research have led to the release of improved crop

varieties, new farming techniques and crop

produc-tion methods, and the development of policies to

help rural populations, especially in developing

coun-tries, manage natural resources in a sustainable way

Lakhdar Boukerrou

Web Site

Consultative Group on International

Agricultural Research

http://www.cgiar.org

See also: Agriculture industry; Agronomy;

Green-house gases and global climate change; Land

Insti-tute; Land-use planning

Copper

Category: Mineral and other nonliving resources

Where Found

Copper deposits are found in several types of geologic

environments Most common are the porphyry

cop-per ore deposits that formed in magmatic arcs

associ-ated with subduction zones These types of ores are

found in Canada, the western United States, Mexico,

Peru, and Chile Other important copper deposits

were formed by different processes and are found in

central Europe, southern Africa, Cyprus, Indonesia,

and Japan

Primary Uses

The major uses of copper are in the electrical industry

because of the substance’s ability to conduct

electric-ity efficiently Copper is also utilized extensively in the construction industry especially for plumbing Most

of the remaining copper is alloyed with other metals

to make bronze (with tin), brass (with zinc), and nickel silver (with zinc and nickel, not silver)

Technical Definition Copper (chemical symbol Cu) is a reddish mineral that belongs to Group IB of the periodic table Cop-per has an atomic number of 29 and an atomic weight

of 63.546, and it is composed of two stable isotopes, copper 63 (69.17 percent) and copper 65 (30.83 per-cent) Pure copper has a face-centered cubic crystal-line structure with a density of 8.96 grams per cubic centimeter at 20° Celsius The melting point of cop-per is 1,083° Celsius, and the boiling point is 2,567° Celsius

Description, Distribution, and Forms Copper is a ductile metal and a good conductor of heat and electricity It is not especially hard or strong, but these properties can be increased by cold working

of the metal

Copper is a relatively rare element, making up only

50 parts per billion in the Earth’s crustal rocks It oc-curs in nature both in elemental form and incorpo-rated into many different minerals The primary min-erals are the sulfides (chalcopyrite, bornite, covellite, and others), oxides (cuprite and others), and carbon-ates (malachite and azurite) Copper has two valences (degrees of combining power), +1 and +2, and impor-tant industrial compounds have been synthesized us-ing both oxidation states The most useful industrial +1 (cuprous, or Cu I) compounds are cuprous oxide (Cu2O), cuprous sulfide (Cu2S), and cuprous chlo-ride (Cu2Cl2) Important +2 (cupric, or Cu II) com-pounds used by industry are cupric oxide (CuO), cu-pric sulfate (CuSO4), and cupric chloride (CuCl2) Although copper is relatively rare in the crust of the Earth, it has been concentrated into ore deposits

by geologic processes There are four major types of copper ore deposits, each formed by a different set of geologic events

Most of the copper mined is taken from porphyry copper deposits These deposits are composed of cop-per minerals disseminated fairly evenly throughout porphyritic granitic rocks and associated hydrother-mal veins The primary ore mineral is chalcopyrite, a copper/iron sulfide Porphyry copper ore deposits are generally located in rocks that have been formed

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near convergent plate boundaries where the granites

have been produced from magma generated during

the subduction of an oceanic plate beneath a

conti-nental plate This tectonic regime has existed along

the western coasts of North America and South

Amer-ica for more than 200 million years; consequently,

gi-ant porphyry copper deposits are found in western

Canada, the western United States, Mexico, Peru, and

Chile The world’s two largest producers of copper

are Chile and the United States, and the largest

cop-per ore deposit in the world is located in Chile Other

porphyry copper deposits are found in Australia, New

Guinea, Serbia, the Philippines, and Mongolia

A second kind of copper ore deposit is commonly called a Kupferschiefer type because of the large quantity of copper found in the Kupferschiefer shale

of central Europe The copper occurs in a marine shale that is associated with evaporites and nonmarine sedi-mentary rocks The origin of the copper in these ores

is still debated The Zambian-Democratic Republic of the Congo copper belt of southern Africa contains more than 10 percent of the world’s copper reserves Copper is also found in massive sulfide deposits

in volcanic rocks, ophiolites, greenstone belts, and fumarolic deposits Copper-bearing massive sulfide ores are found in Canada, Cyprus, and Japan

Data from the U.S Geological Survey, U.S Government Printing Office, 2009.

650,000 460,000 270,000

1,220,000

430,000

750,000 1,310,000

560,000

2,030,000

Metric Tons

6,000,000 5,000,000

4,000,000 3,000,000

2,000,000 1,000,000

Zambia

Poland

Peru

Mexico

Kazakhstan

Indonesia

Russia

United States

Other countries

China

Chile

Canada

Australia 850,000

590,000

5,600,000 1,000,000

Copper: World Mine Production, 2008

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A fourth type of copper deposit is found on the

deep-ocean floors, where manganese nodules have

formed very slowly in areas of unusually slow

sedimen-tation These nodules contain not only manganese but

also copper, cobalt, and nickel in economically

im-portant concentrations Since these nodules

gener-ally form in water depths of 900 to 2,000 meters, they

are difficult to mine They do, however, represent an

important potential source of copper for the future

Copper is an essential trace element of life and is

found in various concentrations within plants and

ani-mals For example, copper is found in many

blue-blooded mollusks and crustaceans because it is the

central element in hemocyanin, a molecule that

trans-ports oxygen in the organisms It is found in lesser

concentrations in many other organisms, such as

sea-weeds, corals, and arthropods

Copper can be found in most soils, and its absence

or unavailability to plants will cause the soil to be

rela-tively infertile For example, many muck soils that are

very rich in organic material cannot sustain plant life

because the copper is bound to the organic matter

and is therefore not available to plants

Some soils have suffered from copper pollution

at-tributable to the excess of copper-bearing fertilizers

and the application of copper-rich fungicides or

sew-age wastes to the land Research has shown that the

ac-cumulations of copper in these soils will not be

effec-tively leached from the land for decades or even

centuries because the copper has an affinity for soil

colloids that can tightly bind the copper

Copper is distributed throughout the Earth’s

litho-sphere, hydrolitho-sphere, atmolitho-sphere, and pedosphere

in various concentrations About 5 percent of the

cop-per content of the lithosphere is found in

sedimen-tary rocks, particularly shale, and only about 0.00004

percent in soils Only about 0.001 percent of the

cop-per of the lithosphere is in exploitable

concentra-tions, and some of these deposits have been mined for

centuries The total production of copper by mining

is approximately 300 million metric tons, of which

about 80 percent was mined in the twentieth century

Almost 30 percent of the entire world’s historic

pro-duction of copper was mined in the 1980’s The total

copper mined amounts to about twice the total

cop-per in the upcop-per 2 centimeters of soil worldwide and

nearly ten times the total copper found in all living

or-ganisms Much of the copper produced has been used

and then disposed of on land or wasted in water or the

atmosphere The impact of the transfer of this much

copper from the deposits of the crust to the surface of the Earth is not yet well understood

The total amount of copper released into the atmo-sphere has been estimated to be almost three times the amount of carbon in the atmosphere today The residence time of copper in the atmosphere is quite short, and there probably has not been a significant buildup of copper over time, but the atmosphere does act as a medium for transferring copper around the globe Copper pollution of many local ecosystems has been well documented in areas near smelters and copper mines Although it is clear that copper con-centrates in the soils and waters near the areas, the im-pact of copper pollution is often hard to separate from the environmental effects resulting from in-creased levels of other heavy metals and from sulfur dioxides and other gases released from smelters Research has also shown that urban areas generally have much higher levels of copper in the soils and air than are found in rural areas In many cases the cop-per concentration in urban soils is more than ten times that of nearby rural areas In addition, it is well established that the dumping of sewage into rivers, lakes, and the ocean can raise the concentrations of copper in the sediments by factors of two to one hun-dred times the background levels in unpolluted areas However, distinguishing the environmental impact of copper from the effects of the associated metals found in sewage effluent is difficult

Copper is an essential element in the human diet

It is found in several oxidative enzymes, such as cyto-chromes a and a3, ferroxidase, and dopamine hy-droxylase The copper is used by enzymes in the oxi-dation and absorption of iron and vitamin C The level of copper in the body is primarily controlled by the excretion of the element in bile Absorbed copper

is probably stored internally by some intracellular proteins

Generally, copper deficiencies in humans are rare There are two known genetic diseases, Wilson’s dis-ease and Menkes disdis-ease, that disrupt copper metabo-lism In Wilson’s disease, an unknown mechanism re-stricts the excretion of copper in bile, and as a result copper builds up in various tissues in the body Once diagnosed, Wilson’s disease can be treated by giving the patient a chelating agent to remove the accumu-lated copper Menkes disease, commonly called steely

or kinky hair syndrome, causes inefficient utilization

of copper in the body This lack of copper affects the normal formation of connective tissue and the loss of

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some widespread enzymatic activity.

Death generally occurs within the

first three years

History

Copper was one of the first metals

mined and used by humans It, along

with gold and silver, occurs naturally

as a free elemental metal and thus

can be extracted and used without

smelting or refining Neolithic

hu-mans probably learned that this

un-usual metal could be shaped by

ham-mering with stone tools and that the

copper tools could be hardened by

continued cold working The first use

of copper probably predated 8000

b.c.e By 6000 b.c.e it was known

that copper could be melted in crude

furnaces and poured into casts to

elaborate weapons and ornaments

Egyptian copper artifacts are dated as far back as

5000 b.c.e., and ancient Egyptians appear to have

been the first to alloy copper with tin to make bronze

The earliest record of a bronze artifact dates to about

3700 b.c.e Bronze makes better weapons and

orna-ments because it is much harder and tougher than

pure copper As a result, the bronze technology spread

throughout the Middle East and into Asia Bronze

items at least as old as 2500 b.c.e have been found in

China, but the alloy may have been used earlier

Bronze was superseded by iron as the metal of

choice for weapons and for structural uses This

tech-nological advance occurred after furnaces were

devel-oped that could obtain temperatures high enough to

smelt iron from its ores After the introduction of iron

and later steel into common use, copper and its alloys

were used primarily for ornaments, utensils, pipes for

plumbing, and coinage Because of its natural

resis-tance to most corrosion caused by air and seawater,

copper was commonly utilized for purposes requiring

such protection The discovery of electricity and the

invention of the incandescent lightbulb and electric

motors led to the extensive use of copper for the

trans-mission of electricity This became the most common

and most important use of copper

Obtaining Copper

Copper is mined in fifty to sixty countries worldwide,

with Chile accounting for about 35 percent of the

production in 2008 The primary ore minerals of cop-per are chalcopyrite (copcop-per-iron sulfide), chalcocite (copper sulfide), covellite (copper sulfide), azurite (copper carbonate), and malachite (copper carbon-ate) Other ore minerals of lesser importance are na-tive copper, bornite, enargite, tetrahedrite, cuprite, tenorite, chalcanthite, and chrysocolla

The copper sulfide minerals are found in por-phyry, massive sulfide, and Kupferschiefer type depos-its, and the copper carbonates and copper oxides are commonly found in the upper zones of such deposits that have been exposed to weathering and ground-water action

Much of the copper of the world is extracted from open-pit mines that expose the ore deposits The overburden of surrounding rock or soil covering the ore is physically removed, and the ore extracted by drilling and detonating explosives to loosen the ore Underground mining is done using standard tech-niques of tunneling and blasting The ore from either underground mines or open-pit mines is then gath-ered and hauled to ore processing plants, where the ore is crushed and the copper and other metals are concentrated The concentrated ore usually mea-sures 20 to 30 percent copper, and it is then either smelted or leached to produce a relatively high con-centration of copper, which still contains some impu-rities This smelted copper is then electrolytically re-fined to a purity of more than 99 percent

A worker in a Chinese factory guides a forklift loaded with rolls of copper tubes (AP/

Wide World Photos)

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Uses of Copper

Copper was one of the first metals

used by humans because it can be

found in nature as pure metal and

can be worked easily by hand Pure

copper was probably first mined and

used by humans around 8000 b.c.e

Through the ensuing ages, copper

has remained an important metal

and a component of such important

materials as pewter, brass, and other

bronzes After the Industrial

Revo-lution, copper became the second

most used metal in the industrial

world behind only iron However,

the discovery of aluminum, its

prop-erties, and its general availability

made aluminum more useful in

mod-ern society

Copper is one of the most

com-monly used metals in the world, and,

because of its special qualities of high

ductility and electrical conductivity,

it is used extensively in the electrical

industries Copper that has been

re-fined electrolytically is up to 99.62 percent pure; the

primary remaining material is oxygen The oxygen

helps to increase the density and conductivity of

cop-per wire The wire can be produced in large quantities

by rolling the copper into rods, which are then drawn

through tungsten carbide or diamond dies to form

the wire

Copper is also produced in sheets or smaller strips

by initially rolling hot copper, with later rollings done

with cold copper The resultant strips or sheets are

generally of even thickness and uniform surface

ap-pearance This strip copper can be cut or pressed to

be used in the electrical or construction industries

One of the earliest uses of copper was in the

pro-duction of bronze The early bronzes were copper/

arsenic alloys; later, tin was added at various

concen-trations Modern bronzes are alloys of copper and tin,

and they are used primarily for ornaments, bells, and

musical instruments The bronze used in making

bells and musical instruments usually contains up to

20 percent tin to impart the proper tonal qualities to

the sounds produced from these instruments

An-other traditional use for copper is in the production

of pewter, which is an alloy of copper and lead Since

lead is highly toxic, the use of pewter has been

re-stricted in recent times and is generally reserved for ornamental pieces

Brass is a widely used alloy of copper and zinc Al-though the copper content of brass can range from less than 5 percent to more than 95 percent, only brasses

of at least 55 percent copper can be worked and used industrially White brasses contain more than 45 per-cent zinc and are not at all malleable and thus are not useful for industrial purposes The various relative concentrations of copper and zinc produce brasses of widely varying physical properties of hardness, ductil-ity, and malleability Many brasses can be drawn into wire, rolled into sheets, or formed into rods

Copper and nickel are completely miscible and therefore can be mixed in any relative concentration The various mixtures produce alloys with various physi-cal properties and different industrial uses The alloys using 2 percent to 45 percent nickel produce a mate-rial with a much higher hardness than pure copper, and the mixture of about 20 percent nickel produces

an extremely ductile alloy that can be cold worked without annealing This makes this mixture useful for drop forging, cold stamping, and pressing Indus-trially this alloy is commonly used for fittings in the au-tomobile industry and for bullet sheathing Copper

Source: Mineral Commodity Summaries, 2009

Data from the U.S Geological Survey, U.S Government Printing Office, 2009.

Building construction 49%

Electrical

& electronic products 21%

Industrial machinery

& equipment 9%

Transportation equipment 10%

Consumer

& general products 11%

U.S End Uses of Copper and Copper Alloy Products

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and nickel occur together in some ores and can be

smelted to produce a natural alloy called Monel metal

The natural ores usually also contain some manganese,

which, with other impurities, is incorporated in the

al-loy It is also produced artificially by mixing the

appro-priate levels of nickel, copper, and manganese Monel

metal is extremely strong at normal and high

temper-atures and thus has many engineering applications

Copper can also be alloyed with various metals to

form other types of bronzes It can be mixed with 9

per-cent aluminum to form aluminum bronzes, which

are corrosion-resistant metals Manganese bronzes,

which are high-strength alloys, usually contain

cop-per, zinc, aluminum, and 2 to 5 percent manganese

The addition of 1 to 3 percent silicon and 1 percent

manganese to copper produces the silicon bronzes,

which have good welding and casting qualities A very

strong alloy of copper and about 2 percent beryllium

can be strengthened by heat working and will

pro-duce a metal with a hardness equal to that of many of

the harder steels

Many copper-containing compounds are used for

industrial purposes Cuprous oxide is used as an

anti-fouling agent in some paints and to give some glass a

red color A green color can be imparted to glass by

cupric oxide, and cupric chloride is used in the

manu-facture of some pigments Copper sulfate is commonly

used as a desiccant and in the production of

electro-lytically refined copper Like many other copper

com-pounds, copper carbonates impart strong blue or

green colors to solutions and are used in the

produc-tion of many pigments Copper can also be combined

with arsenic; these compounds are used as insecticides

Jay R Yett

Further Reading

Adriano, Domy C “Copper.” In Trace Elements in

Terres-trial Environments: Biogeochemistry, Bioavailability,

and Risks of Metals 2d ed New York: Springer, 2001.

Brookins, Douglas G Mineral and Energy Resources:

Oc-currence, Exploitation, and Environmental Impact

Co-lumbus, Ohio: Merrill, 1990

Greenwood, N N., and A Earnshaw “Copper, Silver,

and Gold.” In Chemistry of the Elements 2d ed

Bos-ton: Butterworth-Heinemann, 1997

Joseph, Günter Copper: Its Trade, Manufacture, Use, and

Environmental Status Edited by Konrad J A Kundig.

Materials Park, Ohio: ASM International, 1999

Krebs, Robert E The History and Use of Our Earth’s

Chemical Elements: A Reference Guide Illustrations by

Rae Déjur 2d ed Westport, Conn.: Greenwood Press, 2006

Linder, Maria C Biochemistry of Copper Vol 10 in Bio-chemistry of the Elements New York: Plenum Press,

1991

National Research Council Copper in Drinking Water.

Washington, D.C.: National Academy Press, 2000

Nriagu, Jerome O., ed Copper in the Environment.

2 vols New York: Wiley, 1979

Web Sites Copper Development Association, Inc

Copper.org: The Ultimate Source for Information

on Copper and Copper Alloys http://www.copper.org

Natural Resources Canada Canadian Minerals Yearbook, Mineral and Metal Commodity Reviews

http://www.nrcan-rncan.gc.ca/mms-smm/busi-indu/cmy-amc/com-eng.htm

U.S Geological Survey Copper: Statistics and Information http://minerals.usgs.gov/minerals/pubs/

commodity/copper See also: Alloys; Bronze; Metals and metallurgy; Mining wastes and mine reclamation; Plate tectonics; Plutonic rocks and mineral deposits; Secondary en-richment of mineral deposits

Coral reefs

Categories: Ecological resources; plant and animal resources

Where Found Typical coral reefs occur in shallow water ecosystems

of the Indo-Pacific and Western Atlantic regions Lesser known cold-water reefs are found at depths be-tween 40 and 3,000 meters along continental shelves, continental slopes, seamounts, and fjords worldwide

Primary Uses Reefs protect shorelines from wave action and storm damage Historically, coral has been used in bricks and for mortar Other uses include souvenirs, aquar-ium specimens, and even human bone grafts

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The diverse array of plants, invertebrate animals,

and vertebrate life that a reef supports are used by

humans as food, living and preserved displays, and

traditional medicine Bioprospecting has identified a

promising chronic-pain treatment from a reef

mol-lusk Two possible cancer drugs and an anti-asthma

compound have been isolated from reef sponges

Technical Definition

Corals are animals in the phylum Cnidaria, kin to

jelly-fish As members of the class Anthozoa, they are

closely related to sea anemones Reef-building corals

secrete calcium carbonate (CaCO3) skeletons that

surround the individual soft-bodied organisms

com-prising the colony The living layer mounts itself on

layer upon layer of the unoccupied skeletons of its

ancestors

Corals are carnivorous, capturing and stinging

zoo-plankton with tentacles surrounding the single

open-ing that serves as mouth and anus Corals derive a

greater amount of nourishment from photosynthetic algae living within cells lining their digestive cavity Bleaching refers to the loss of these endosymbionts, called zooanthellae, from the coral host or loss of pig-ment from the algae Coral may or may not recover from a bleaching episode

Description, Distribution, and Forms According to the Global Coral Reef Monitoring Net-work, 20 percent of reefs have been lost, 24 percent risk imminent collapse because of human pressure, and 26 percent are threatened with collapse over time Threats to this diverse, productive, complex, and fragile ecosystem are wide-ranging Some of the damage originates from imbalances on land Nutrient excesses run off farms and end up in the oceans, feed-ing explosive reproduction of bacteria The bacteria use up the available oxygen, creating uninhabitable

“dead zones.” Another chain reaction begins with de-forestation Increased erosion washes large amounts of

This coral reef in Bonaire, the Netherlands Antilles, was badly damaged by a 2008 hurricane (Roger L Wollenberg/UPI/Landov)

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soil into the waterway, increasing water turbidity, which

blocks light to the coral’s zooanthellae Particulate

matter also settles onto the corals, smothering them

Pollution from the construction and operation of

ma-rinas, prawn farms, desalination plants, sewage

treat-ment works, and hotels further degrades the reefs

Ship grounding, channel dredging, deep-water

trawl-ing, oil and gas exploration, laying of communication

cable, dynamite and cyanide fishing, and tourism

each take a toll

Environmental stress renders corals more

suscepti-ble to disease Disproportionate changes in

herbi-vores and predators further disrupt life on the reef

Reduced herbivory by sea urchins or parrot fish allows

algae to replace corals When tritons, large predatory

snails, are harvested for their showy shells, population

explosions of the crown-of-thorns starfish can

deci-mate reefs

Storms, such as the 2004 tsunami in the Indian

Ocean, shatter and smother large numbers of corals

Climate change will likely expose the reefs to

intolera-ble temperature fluctuations Low temperatures in

1968, high temperatures in 1987, and major El Niño

and La Niña events in 1998 each caused wide-ranging

bleaching Rising levels of carbon dioxide, combined

with warmer seawater, inhibit formation of the corals’

skeletons

Designating marine protected areas (MPAs), of

which the United States has two hundred, is intended

to enhance the management and monitoring of

unique ocean ecosystems such as coral reefs

How-ever, fishing and resource extraction are allowed to

continue in MPAs, so reef conservation requires

stronger protection, such as “no-take areas.”

Australia’s Global Coral Reef Monitoring Network

publishes the Status of Coral Reefs of the World

biannu-ally It includes recommendations for reef

conserva-tion from more than eighty countries Nearly one-half

of the coral reef countries and states have populations

under 1 million Roughly half of those have less than

100,000 inhabitants It stands to reason that with less

international political clout, banding together

ad-vances protection of the reefs

An area equal to 1 percent of the world’s oceans,

190 million kilometers, is covered by coral reefs

Indo-nesia has the largest area of warm-water (18°-32°

Cel-sius) reefs Norway is estimated to have the most

cold-water (4°-13° Celsius) coral reefs Cold-cold-water reefs

occupy depths below light penetration Rather than

relying on photosynthetic algae, cold-water reefs are

supplied particulate and dissolved organic matter and zooplankton by currents Species diversity of coral and associated organisms is lower, and the reefs grow more slowly than their tropical counterparts Individual corals are measured in millimeters To-gether, billions of these animals form reef structures

as imposing as Australia’s Great Barrier Reef, which is 2,000 kilometers long and 145 kilometers wide This is even more impressive when one realizes that a reef may grow as little as 1 meter in one thousand years Dependent upon coral species and physical envi-ronment, reefs can be branching, massive, lobed, or folded On a larger scale, reefs are fringing, barrier, atoll, or platform Fringing reefs extend from the shoreline Barrier reefs run parallel to the coast, sepa-rated from shore by a lagoon An atoll is a living reef around a central lagoon Platform reefs lie far off-shore, in calm waters; they are flat-topped with shal-low lagoons

History Coral reef history stretches back hundreds of millions

of years Coral larvae that gave rise to modern-day reefs settled on limestone during the Holocene ep-och, ten thousand years ago Humans have been ex-ploiting reef resources for the past one thousand years Atlantic warm-water reefs are less diverse than those of the Pacific Reasons for this disparity include lower temperatures, younger geologic age of the ocean, and lower sea levels during the Ice Age in the Atlantic than in the Pacific

Charles Darwin published The Structure and Distri-bution of Coral Reefs in 1842 One hundred years ago,

the world’s reefs were healthy Pollution and sedimen-tation had not emerged as problems, and natural fish populations were harvested sustainably

In the 1950’s, the geology of reef formation, reef zonation and productivity, and the role of disturbance were areas of study advanced considerably with the widespread use of scuba gear During the 1980’s, re-search shifted to human impact and decline of coral reefs and how to conserve and restore reefs

The study of cold-water reefs awaited necessary in-strumentation and deep submersibles, available only since the late 1990’s Within the same time frame, the Kyoto Protocol limited carbon emissions, one-third

of the Great Barrier Reef was designated a no-take area, and sea urchins returned the balance to Carib-bean reefs, each a measure that promises to improve the health of coral reefs

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Obtaining Reef Resources

Coral reefs support the marine aquarium trade and

luxury live food markets Fishes and reef organisms

are captured by hand, hook and line, spear, nets, and

trawl nets Overfishing has led to reliance on methods

with indiscriminate by-catch and habitat destruction

via dynamite and cyanide fishing Handling and

trans-fer mortality drive extraction rates even higher in

order to meet global demand

Uses of Reef Resources

The main uses of coral reefs are their in situ ecosystem

services The vivid interdependency of the diversity

they support rivals that of tropical rain forests

Hun-dreds of species of coral support thousands of other

organisms, including, but not limited to, algae,

sea-grass, plankton, sponges, polychaete worms, mollusks,

crustaceans, echinoderms, and fish More than

one-half of all marine fish species are found on coral reefs

and reef-associated habitats Larger predators, such as

sharks and moray eels, feed on the fish The extensive

coral reef food web cycles nutrients in oligotrophic

(nutrient-poor) tropical waters

Over millennia, coral reefs have formed landmasses

rising up from the sea The Maldives, Tuvalu, the

Mar-shall Islands, and Kiribati are atoll countries sitting

atop coral islands The Florida keys are well-known

coral islands

Calcification in corals, mollusks, and others

se-questers one-third of human-induced CO2emissions

Loss of this carbon sink would exacerbate the effects

of climate change The value of that cannot be

mea-sured Tourism, fishing, and ecosystem services are

valued at hundreds of billions of dollars annually

Used in traditional medicine for centuries, reef

or-ganisms continue to be studied for use in Western

medicine Antiviral, antifungal, and anticancer

prod-ucts; inflammatory response mediators; and even

sun-block are under development, some of which have

already been administered to patients Marine

bio-technology is a multibillion-dollar industry, with strong

growth potential Ultimately, the health of humanity

is tied to the health of the reefs

Sarah A Vordtriede

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