From: LARRY KLAES (ljk4@msn.com)
Date: Thu Aug 01 2002 - 13:09:27 PDT
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From: cunews@cornell.edu
Sent: Wednesday, July 31, 2002 4:53 PM
To: CUNEWS-AG-L@cornell.edu; CUNEWS-LIFE_SCIENCE-L@cornell.edu; CUNEWS-SCIENCE-L@cornell.edu
Subject: Cornell News: Alien species invade
Cornell ecologist's book on alien invaders more than summertime
thriller: It's a nonfiction account of introduced species'
destructive impact
FOR RELEASE: July 31, 2002
Contact: Roger Segelken
Office: 607-255-9736
E-mail: hrs2@cornell.edu
ITHACA, N.Y. -- As a respite from summertime weed-whacking,
fly-swatting and pest-repelling, a new book edited and co-authored by
Cornell University ecologist David Pimentel makes compelling reading.
But readers of Biological Invasions: Economic and Environmental Costs
of Alien Plant, Animal, and Microbe Species (CRC Press, 2002) won't
want to tarry too long. An estimated 50,000 "exotics" are causing
tens of billions of dollars in harm each year in the United States,
according to the new book, and more are on the way. And they're not
arriving via spaceships, but in the thousands of aircraft and
sea-going ships in everyday commerce, the authors observe.
The book covers many of the more than 120,000 non-indigenous species
that have invaded six countries (the United States, United Kingdom,
Australia, India, South Africa and Brazil) and gives special emphasis
to globe-traveling exotic diseases before making recommendations to
help nations slow the influx.
"The impact of invasive species is second only to that of human
population growth and associated activities as a cost of loss of
biodiversity throughout the world," says Pimentel, a professor
emeritus in Cornell's College of Agriculture and Life Sciences. "In
the United States, invasions of non-native plants, animals and
microbes are thought to be responsible for 42 percent of the decline
of native species now listed as endangered or threatened." The names
of some invading species are threatening enough. For instance, giant
hogweed, a perennial herb in Britain, is blamed for serious
dermatitis when it contacts skin. Root-rot fungus is a plant disease
spread through Australia by feral pigs, which themselves are
non-native down under. Paterson's curse, a weed that invaded
Australian pastures, sickens sheep by damaging their livers with
plant toxins. Yet the screw-worm fly is a curse to cattle in tropical
regions everywhere in the world -- except Australia.
Other invaders sound like they stowed away in shipments of Harry
Potter books: Oxford ragwort was deliberately imported from Sicily 's
Mount Etna for cultivation in the Oxford Botanic Gardens in the 1700s
and now is spreading though Ireland and Scotland; ivy-leafed toadflax
was introduced a century before ragwort and now is a common English
herb; and paddy brown spot has nothing to do with Paddington Bear but
is a serious plant disease that arrived in India on imported seeds
and caused the Bengal famine of 1943 in which 2 million perished.
Certain microbes need no introduction, and they didn't need a visa to
traverse the continents and cause contagion. Tuberculosis, AIDS,
hepatitis, influenza, cholera, bubonic plague are among diseases that
the book blames on introduced pathogenic microbes. In the United
States alone, health-care costs for AIDS average $6 billion a year,
while a single outbreak of influenza can incur $300 million in
hospitalization costs and take hundreds of lives, says Pimentel. "An
increasing threat of exotic diseases exists because of rapid
transportation, encroachment of civilization into new ecosystems and
increasing environmental degradation," he writes.
The editor-author and his 44 contributing scientist-writers are
careful to note that not all introduced species have entirely
deleterious effects in their new homes, and many are depended on for
human sustenance. Some 98 percent of the U.S. food supply comes from
introduced species, such as corn, wheat, rice and other crops, as
well as cattle, poultry and other livestock.
Or take the example of Paterson's curse (Echium plantagineum) on
Australia. When the weed's toxic alkaloids aren't ruining animals'
livers, its flowers produce nectar used by bees for a pale honey that
fetches a premium price in the Japanese market. And in the semi-arid
rangelands of northern South Australia, the damaging pasture weed is
considered such a useful fodder, when handled properly, that
cattlemen call it "salvation Jane." However, economic analysts cited
in Biological Invasions call Paterson's curse a mixed blessing to the
Outback, with an estimated $30 million in annual costs and only $2
million in benefits.
In fact, only 20 to 30 percent of the 120,000 non-indigenous species
become pests and cause major environmental damage, the authors
acknowledge. That proportion, however, is more than enough to merit
control efforts and attempts to prevent future invasions.
"All introductions of non-native plants, animals and microbes, for
whatever purposes -- including agriculture, hunting, tourism, pets,
recreation and research -- should be strictly regulated," Pimentel
and his co-authors conclude. "In addition, the government should
make every effort to inform the public concerning the serious
environmental and economic threats that are associated with alien
species introductions."
Related World Wide Web sites: The following sites provide
additional information on this news release. Some might not be part
of the Cornell University community, and Cornell has no control over
their content or availability.
o Publisher: <http://www.crcpress.com/>
o Department of Ecology and Evolutionary Biology: <http://www.eeb.cornell.edu/>
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The web version of this release may be found at
http://www.news.cornell.edu/releases/July02/alien_invaders.hrs.html
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