Why Save End Species July 2005

8/14/2019 Why Save End Species July 2005

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Why SaveEndangeredSpecies?

U.S. Fish & Wildlife Service


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Since life began on Earth,countless creatures havecome and gone, renderedextinct by naturally

changing physical andbiological conditions.

Since extinction is partof the natural order, andif many other speciesremain, some people ask:

Why save endangered

species? Why should wespend money and effortto conserve them?

How do we benefit?


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Congress answered these questionsin the preamble to the EndangeredSpecies Act of 1973, recognizing thatendangered and threatened species of

wildlife and plants are of esthetic,ecological, educational, historical,recreational, and scientific value tothe Nation and its people. In thisstatement, Congress summarizedconvincing arguments made byscientists, conservationists, and

others who are concerned by thedisappearance of unique creatures.Congress further stated its intentthat the Act should conserve theecosystems upon which endangeredand threatened species depend.

Although extinctions occur naturally,scientific evidence strongly indicatesthat the current rate of extinctionis much higher than the natural orbackground rate of the past. Themain force driving this higher rate of

loss is habitat loss. Over-exploitationof wildlife for commercial

purposes, the introduction ofharmful exotic (nonnative)

organisms, environmentalpollution, and the spreadof diseases also pose

serious threats to ourworlds biological

heritage.

Passengerpigeons oncenumbered inthe billions butnow exist only inmuseums.

Chip Clark/Smithsonian

Institution


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Conservation actions carried outin the United States under theEndangered Species Act have beensuccessful in preventing extinction

for 99 percent of the species that arelisted as endangered or threatened.However, species loss on a globalscale continues to increase due tothe environmental effects of humanactivities.

Biologists estimate that since thePilgrims landed at Plymouth Rockin 1620, more than 500 species,subspecies, and varieties of ourNations plants and animals havebecome extinct. The situation in

Earths most biologically richecosystems is even worse. Tropicalrainforests around the world, whichmay contain up to one half of all livingspecies, are losing millions of acresevery year. Uncounted species arelost as these habitats are destroyed.

In short, there is nothing naturalabout todays rate of extinction.

Right: Formerrainforest habitat

Below: Intactrainforest atdawn C

IA

CEC

B/BUPhotoLibrary


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Not too long ago, almost one quarter of the trees in theAppalachian forests were American chestnuts. They helpedsupport not only wildlife but the people living amongthem. Chestnuts were an important cash crop for many

families. As year-end holidays approached, nuts by therailroad car were sold and shipped to northeastern cities.Chestnut timber, strong and rot resistant, was prized forbuilding barns, fences, furniture, and other products. Thisphotograph of the Shelton family, taken around 1920, showsthe size American chestnut trees once reached.

First detected in 1904, an Asian fungus to which nativechestnuts had little resistance appeared in New York Citytrees. The blight spread quickly, and by 1950 the Americanchestnut was virtually extinct except for occasional rootsprouts that also became infected. Organizations suchas the American Chestnut Foundation are working with

plant breeders to develop a disease resistant strain andrestore it to the eastern forests.

Cou

rtesyofGreatSmokyM

ountainsNationalPark

andtheAmericanChes

tnutFoundation


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Benefits of Natural DiversityHow many species of plants andanimals are there? Although scientistshave classified approximately

1.7 million organisms, they recognizethat the overwhelming majority havenot yet been catalogued. Between10 and 50 million species may inhabitour planet.

None of these creatures exists in a

vacuum. All living things are part ofa complex, often delicately balancednetwork called the biosphere. Theearths biosphere, in turn, is composedof countless ecosystems, which includeplants and animals and their physical

environments. No one knows how theextinction of organisms will affectthe other members of its ecosystem,but the removal of a single speciescan set off a chain reaction affectingmany others. This is especially truefor keystone species, whose loss can

transform or undermine the ecologicalprocesses or fundamentally changethe species composition of the wildlifecommunity.

Chisos Mountain hedgehog

Do

nKurz


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The gray wolf is one such keystonespecies. When wolves were restoredto Yellowstone National Park, theystarted to control the parks largepopulation of elk, which had been

over consuming the willows, aspen,and other trees that grew alongstreams. The recovery of these treesis cooling stream flows, which benefitsnative trout, and increases nestinghabitat for migratory birds. Beaversnow have willow branches to eat,and beaver dams create marshlandhabitat for otters, mink, and ducks.

Wolves even benefit the threatenedgrizzly bear, since grizzlies find iteasier to take over a wolf kill than tobring down their own elk.

Contributions to MedicineOne of the many tangible benefitsof biological diversity has been itscontributions to the field of medicine.Each living thing contains a uniquereservoir of genetic material thathas evolved over eons. This materialcannot be retrieved or duplicatedif lost. So far, scientists haveinvestigated only a small fractionof the worlds species and have justbegun to unravel their chemical

secrets to find possible human healthbenefits to mankind.

TracyBrooks

Gray wolf


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No matter how small or obscure aspecies, it could one day be of directimportance to us all. It was onlya fungus that gave us penicillin,

and certain plants have yieldedsubstances used in drugs to treatheart disease, cancer, and a variety ofother illnesses. More than a quarterof all prescriptions written annually inthe United States contain chemicalsdiscovered in plants and animals. If

these organisms had been destroyedbefore their unique chemistries wereknown, their secrets would have died

with them.

A few hundred wild species have

stocked our pharmacies withantibiotics, anti-cancer agents, painkillers, and blood thinners. Thebiochemistry of unexamined species isan unfathomed reservoir of new andpotentially more effective substances.The reason is found in the principles

of evolutionary biology. Caught in anendless arms race with other formsof life, these species have devisedmyriad ways to combat microbesand cancer-causing runaway cells.Plants and animals can make strange

M.Plotkin

The rosyperiwinkle, aplant native tothe island of

Madagascar, has

yielded powerfulsubstanceseffective intreating childhoodleukemia andother diseases.


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molecules that may never occur to achemist. For example, the anti-cancercompound taxol, originally extractedfrom the bark of the Pacific yew

tree, is too fiendishly complex achemical structure for researchersto have invented on their own, saida scientist with the U.S. NationalCancer Institute. Taxol has becomethe standard treatment for advancedcases of ovarian cancer, which strikesthousands of women every year.But until the discovery of taxolseffectiveness, the Pacific yew wasconsidered a weed tree of no valueand was routinely destroyed duringlogging operations.

Some of the most promising naturalwonder drugs come from compoundsnot usually associated with healing:poisons. One pharmaceutical companyis marketing a blood thinner based onthe venom of the deadly saw-scaled

viper. A protein from another Asianpit viper is being studied becauseit appears to inhibit the spread ofmelanoma cells, and a compoundfrom the venom of some tarantulaspecies may lead to new treatments

for neurological disorders such asParkinsons disease.

Dav

ePowell/U.S.ForestService

JimR

orabaugh

The peeling barkof the Pacific yew,original source ofthe drug taxol.

Tarantula


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SueE

mery

Texas wild rice

Biodiversity and AgricultureMany seemingly insignificant forms of

life are beginning to show importantbenefits for agriculture. Farmers areusing insects and other animals thatprey on certain crop pests, as well asusing plants containing natural-toxinsthat repel harmful insects. These arecalled biological controls, and in

many cases they are a safe, effective,and less expensive alternative tosynthetic chemicals.

Thomas Jefferson once wrote thatthe greatest service which can berendered any country is to add auseful plant to its culture, especiallya breadgrain. It has been estimatedthat there are almost 80,000 species

Somefarmers putup nest boxesto attract bats

that consumeharmful insects.

Merlin D. Tuttle/Bat ConservationInternational


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of edible plants, of which fewer than20 produce 90 percent of the worldsfood. If underutilized species areconserved, they could help to feed

growing populations. One grainnative to the Great Lakes States,Indian wild rice, is superior in proteinto most domesticated rice, and itsincreasing commercial productionearns millions of dollars annually.Crossing it with a related but

endangered species, Texas wild rice,could result in a strain adaptable toother regions of the country.

Ch

ristopherBest

Walkers manioc is an endangered plant endemic tothe Lower Rio Grande Valley of southern Texas andnortheastern Mexico. It is closely related to an importantcrop plant, cassava, which is a staple food in many partsof the world. Walkers manioc could contain genes that

provide salt, drought, cold, or disease resistance for strainsof commercial cassava.


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Environmental MonitorsMany individual species areuniquely important as indicators ofenvironmental quality. The rapiddecline in bald eagles and peregrinefalcons in the mid-20th century wasa dramatic warning of the dangersof DDTa strong, once widely usedpesticide that accumulates in bodytissues. (It hampered fertility and egg-hatching success in these species.) Inanother example, lichens and certainplants like the eastern white pine are

good indicators of excess ozone, sulfurdioxide, and other air pollutants.Species like these can alert us to theeffects of some contaminants beforemore damage is done.

Freshwater mussels are also veryeffective environmental indicators.The eastern United States boaststhe richest diversity of freshwatermussels in the world. These animalsare filter feeders, drawing in waterand straining out food particles. Their

method of feeding helps to keep ourwaters clean. But because mussels

TedSwem

Peregrine falcon


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filter material from the water, theyare often the first animals to beaffected by water pollution. Theytend to accumulate whatever toxins,such as chemicals in agricultural

and industrial runoff, are presentin their habitat. Too much pollutioncan eliminate the mussels. Otherthreats to mussel populationsinclude siltation, the introduction ofcompeting nonnative mussels, streamchannelization and dredging, andthe impoundment of free-flowingstreams and rivers. Today, mostnative freshwater mussel speciesare considered to be endangered,threatened, or of special concern.

Fanshell mussel

RichardBiggins

J.R.Shute/ConservationFisheries,Inc.

Amber darter


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Ecosystem ServicesAs the pioneering naturalist AldoLeopold once stated, To keep everycog and wheel is the first precaution

of intelligent tinkering. As wetinker with ecosystems through oureffects on the environment, whatunexpected changes could occur?One subject of increasing concern isthe impacts these effects can haveon ecosystem services, which is a

term for the fundamental life-supportservices provided by our environment.Ecosystem services include air and

water purification, detoxification anddecomposition of wastes, climateregulation, regeneration of soil

fertility, and the production andmaintenance of biological diversity.These are the key ingredients of ouragricultural, pharmaceutical, andindustrial enterprises. Such servicesare estimated to be worth trillionsof dollars annually. Yet because most

of these services are not traded ineconomic markets, they carry no pricetags that could alert society to changesin their supply or declines in theirfunctioning. We tend to pay attentiononly when they decline or fail.

JohnandKaren

Hollingsworth

Wetlands, like those at the John Heinz National Wildlife

Refuge near Philadelphia, clean water, control flooding,and provide quality wildlife habitat.


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An emerging field calledphytoremediation is an example ofthe ecosystem services providedby plants. Phytoremediation is aprocess that uses plants to remove,transfer, stabilize, and destroy

contaminants in soil and sediment.Certain plant species known as metalhyperaccumulators have the abilityto extract elements from the soiland concentrate them in the easilyharvested plant stems, shoots, andleaves. The alpine pennycress, forexample, doesnt just thrive on soilscontaminated with zinc and cadmium;it cleans them up by removingthe excess metals. In the home,houseplants under some conditionscan effectively remove benzene,

formaldehyde, and certain otherpollutants from the air.

KeithWeller

Alpine pennycress


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Other Economic ValuesSome benefits of animals and plantscan be quantified. For example, theTexas Parks and Wildlife Departmentcalls birding the nations fastestgrowing outdoor recreation. Itestimates that birders pump anestimated $400 million each yearinto the states economy. A hostof small rural towns host festivals

to vie for the attention of thesebirders. Nationwide, the benefitsare even more amazing. In a recentstudy (Birding in the United States:

A Demographic and EconomicAnalysis), the U.S. Fish and WildlifeService estimated that wildlife

watchingnot just bird watchinggenerated $85 billion in economicbenefits to the nation in 2001.

LauraRiley

Birdwatching at J.N. Ding Darling National Wildlife

Refuge on Floridas Gulf Coast.


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Whooping cranes in Texas.

SteveHillebrand

Attwaters greater prairie-chicken, another Texas bird.

GeorgeLavendowski


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Intangible ValuesIf imperiled plants and animalslack a known benefit to mankind,should we care if they disappear?

If a species evolves over millenniaor is created by divine intent,do we have a right to cause itsextinction? Would our descendantsforgive us for exterminating aunique form of life? Such questionsare not exclusive to scientists

or philosophers. Many peoplebelieve that every creature has anintrinsic value. The loss of plantand animal species, they say, isnot only shortsighted but wrong,especially since an extinct species

can never be replaced. Eliminatingentire species has been comparedto ripping pages out of books thathave not yet been read. We areaccustomed to a rich diversity innature. This diversity has providedinspiration for countless writers and

artists, and all others who treasurevariety in the natural world.

San Francisco garter snake

SuzanneL.Collins/Cent

erforNorthAmericanHerpetology


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Among its many values, wildlife is a source of inspiration.For example, the bird paintings by John James Audubon,such as this image of ivory-billed woodpeckers, arerecognized as fine art. Once feared to be extinct, theivory-bill was rediscovered recently in Arkansas.

In his storyThe Bear,

writer WilliamFaulkner depicteda number ofcreatures thatare now rare,including wolves,

panthers, theivory-billed

woodpecker,and, of course,the animal

now known asthe Louisianablack bear.

USFWS


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U.S. Fish & Wildlife ServiceEndangered Species Program4401 N. Fairfax Drive, Rm 420Arlington, VA 22203

http://endangered.fws.gov/

July 2005

Cover photo: Geranium arboreum,d d H ii l t

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Why Save End Species July 2005