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As biodiversity disappears, ecosystems become weak and inefficient,
threatening the health and maintenance of all life. Today, earth’s
biodiversity and its life-sustaining services are being threatened.
Implications of Not Preserving Biodiversity
Water shortages, landslides, soil erosion, fish kills, and forest
fires all result from biodiversity loss. These losses create irreparable
economic and ecological damage.
- The United States is now spending an estimated $7.8 billion
to restore natural ecological processes in the Florida Everglades,
which promises to help restore the health of the region’s biodiversity.(1)
- Only a few decades ago, oysters were capable of keeping the
entire Chesapeake Bay clear by filtering out particles at a rate
estimated to be the equivalent of the entire volume of the bay,
every three days. Over-harvesting has reduced populations by 99%,
and the remaining oysters cannot keep up with the filtering process.(2)
- Species decline is often an early warning sign of a health threat
to all species, including humans. For example, when bald eagle
populations and other birds of prey began to decline due to eggshell
thinning caused by DDT, Americans became aware of the health risks
of DDT and banned its use before humans experienced significant
adverse health affects.
The Reality of Biodiversity Loss
- The Natural Heritage Central Database lists 526 species as extinct
or missing and a recent review of the status of all U.S. species
by the Nature Conservancy reveals that approximately one-third
of U.S. plant and animal species are at risk of extinction.(3)
- In the United States, 37% of freshwater fish species, 67% of
mussels, 51% of crayfish, and 40% of amphibians are threatened
or have become extinct.(4)
- Ninety-eight percent of America’s grasslands are gone, including
98 percent of the original 58 million hectares of tallgrass prairie
in the Midwest and Great Plains.(3)
- Eight-five percent of the virgin forests throughout the U.S.
have been destroyed, with losses estimated at 95-98 percent in
the lower 48 states. For example, old-growth forests of the Pacific
Northwest have declined by 90 percent, and longleaf pine, which
once dominated the uplands of the southeastern coastal plain,
have been reduced by 98 percent.(3)
- Between 90-98% of wild and scenic rivers in the U.S. are degraded.(1)
- Seventy to ninety percent of southern California’s coastal
sage scrub, a diverse and rare habitat type hosting many endemic
species, has been lost to urban and agricultural expansion.(3)
- Ninety percent of the wading birds that once graced Florida’s
Everglades are gone.(3)
- California has lost over 99% of its native grasslands and 85%
of its coastal redwoods.(3)
- The Chesapeake Bay has lost 90% of its submerged aquatic vegetation.(3)
If current rates of biodiversity loss continue...
- There are currently more than 6 billion people living on earth,
and experts predict the world population will reach 9 billion
people in the next 50 years. Incredibly, while the world population
has doubled since 1950, the world economy has quintupled, placing
greater strain and demand on the world’s fixed supply of resources.
- Based on recent extinction rates, an estimated 4% of freshwater
species will be lost in North America each decade, a rate nearly
five times that of terrestrial species.(5)
- Destruction of biodiversity will reduce the quality of life
for future generations, including psychological, emotional, and
spiritual effects from ruined forests, beaches, lakes, mountains,
and open spaces.
What Contributes to Biodiversity Loss?
- Habitat loss from development, fragmentation, and degradation
is the most significant threat to biodiversity in the U.S. Much
of this destruction occurred over a century from farming, logging,
grazing, mining, road building, damming, and channelizing of streams.
Today, the most immediate threat to habitat is from poorly planned
urbanization or sprawl.(3) Each year
2.2 million acres are lost to sprawl.(6)
- Other adverse impacts from sprawl include air and water pollution,
erosion of land cleared for development, stream siltation, reduced
natural capacity to filter pollutants and detoxify waters, and
less capacity to cycle nutrients and compost organic waste.(7)
- Habitat destruction reduces or eliminates populations of a particular
species, which, in turn, reduces genetic diversity, leaving the
species more vulnerable to disease, disaster, and eradication.
- Although roads, developments, and dams do not destroy a large
quantity of habitat outright, they can have an extremely devastating
ecological impact on species’ populations. The fragmentation
that results divides and creates barriers in natural habitat,
leading to the disruption of wildlife movement, dispersal, pollination,
and natural processes, like fires and flooding, and drastically
reduces the ability of the habitat to support species.
- Channelization and bank stabilization projects on the Missouri
River have eliminated the river otter population from this waterway.(8)
- The Willamette River in Oregon lost 80% of riparian forests
and shoreline habitats as a result of straightening and deepening
the river channel.(8)
- Eighty-three percent of 98 threatened or endangered plant species
are threatened primarily by habitat destruction through human
Invasive species threaten biodiversity, habitat quality, ecosystem
function, and produce severe, often irreversible impacts on agriculture,
recreation, and our natural resources. They are the second most
important threat to native species, behind habitat destruction,
having contributed to the decline of 42% of U.S. endangered and
- Invasive species cost the United States approximately $137 billion
per year. These species affect everything from habitat to natural
cycles, like fire cycles and nutrient and water cycling in native
- In 1991, because of reduced carrying capacity from leafy spurge
infestations, ranchers and landowners in South Dakota were losing
$1.4 million per year. The lost forage would have supported beef
herds that could have generated $4.6 million in annual revenues.(11)
- Eurasian watermilfoil was discovered in 11 additional Minnesota
water bodies during 2003. There are now 152 Minnesota lakes, rivers,
and streams known to contain the exotic submersed aquatic plant.(12)
- In Florida, from 1980-1993, managing the invasive plant hydrilla
in public lakes and rivers where it clogs drainage and irrigation
canals, prevents navigation, shades out beneficial native plants,
degrades water quality, and interferes with hydroelectric plants
and urban water supplies, cost $38.5 million; estimates indicate
$10 million is actually needed for adequate annual statewide control.(13)
- Invasive species have played a major role in the listing of
35 to 46 percent of all species currently considered endangered
or threatened in the United States.(1)
- Of the 6 billion people on earth, Americans consume more resources
per person than any other nation, increasing the demands on our
already strained ecosystems and threatening biodiversity.(8)
- The California abalone is one of many fish species on the verge
of extinction due to over-harvesting at fisheries.(14)
- Industrial logging damages and destroys many habitats and ecosystems.(8)
- Illegal trade creates a demand for species that are over-hunted,
placing them at risk of extinction.(8)
- Pollutants weaken immune systems and reproductive capacity,
reducing species’ resilience and ability to maintain adequate
- Though now banned in the U.S., high levels of DDT found in marine
mammals make it difficult for them to reproduce.(15)
- Toxic chemical buildup in ecosystems, primarily DDT, interfered
with bald eagle and other raptor reproduction, and contributed
to a serious population decline from 75,000 nesting bald eagles
in the lower 48 states in 1782 to only 450 nesting pairs by the
- Ozone pollution from the Ohio Valley damages trees in the Appalachian
Global Climate Change
- Deforestation and burning fossil fuels increase the concentrations
of CO2 and other greenhouse gases which
trap heat in the earth’s atmosphere, leading to an increase in
average yearly temperatures on earth.
- Global warming may lead certain species to expand their ranges,
including mosquitoes that carry malaria, encephalitis, and other
- The anticipated speed of climate changes, coupled with direct
loss of natural habitat, may prevent some species from adapting
quickly enough, resulting in death and possible extinction.(1)
- Global warming shifts ecosystems and changes migration patterns.
The ranges for marine life along the Pacific coast, for example,
are shifting northward.(17)
Statewide Biodiversity Information
- Every state has access to biodiversity information through Natural
Heritage Programs and Gap Analysis Programs (GAP) that are complete
or in progress. Many states are forming additional information
collection and assessment agencies as part of their biodiversity
policy. Increasingly, state fish and wildlife agency wildlife
diversity programs, state departments of natural resources, and
even many state universities have information and expertise on
their state’s biodiversity.
Economic Value of Biodiversity
- People travel to mountains, coasts, lakes, and forests for vacation
and spend millions of dollars on hiking, camping, fishing, and
- In 1991, people in the U.S. spent $16 billion on sport fishing.
This is almost twice what was produced by global commercial harvesting
of freshwater fish for consumption in the same year.(1)
- The global estimated value of soil bacterial services provided
by natural species is $33 billion a year.(1)
(1) Alonso, Alfonso, Francisco Dallmeier, Elise Granek, and Peter
Raven, eds. “Biodiversity: Connecting with the Tapestry of Life.”
Washington, D.C.: Smithsonian Institution Monitoring & Assessment
of Biodiversity Program and President’s Committee of Advisors
on Science and Technology: 2001. Smithsonian National Zoological Park.
19 May 2004 <http://nationalzoo.si.edu/ConservationAndScience/MAB/publications/biotapestry.pdf>.
(2) Bryant, Peter J. “Biodiversity and Conservation: The origin, nature
and value of biological diversity, the threats to its continued existence,
and approaches to preserving what is left.” University of California,
Irvine, School of Biological Sciences. 19 May 2002 <http://darwin.bio.uci.edu/~sustain/bio65/Titlpage.htm>.
(3) “The State of Disappearing Species and Habitat: A Sierra
Club Report.” Sierra Club. 19 May 2004 <http://www.sierraclub.org/wildlife/species/habitat_report/intro.asp>.
(4) World Resources Institute in collaboration with the United Nations
Development Programme, the United Nations Environment Programme, and
the World Bank. “World Resources 2000-2001: People and Ecosystems:
The Fraying Web of Life.” Washington, D.C.: World Resources
Institute, September 2000. 19 May 2004 <http://pubs.wri.org/pubs_description.cfm?PubID=3027>.
(5) Ricciardi, Anthony and Joseph B. Rasmussen. “Extinction
Rates of North American Freshwater Fauna.” Conservation
Biology 13.5 (October 1999): p. 1220.
(6) “Sprawl Losses Staggering.” Sierra Club. 19 May 2004
(7) “Biodiversity Threats: Habitat Conversion and Sprawl.”
Biodiversity Project. 19 May 2004 <http://www.biodiverse.org/bdsprawl.htm>.
(8) “Getting on Message: Making the Biodiversity-Sprawl Connection.”
Madison, Wisconsin: Biodiversity Project, December 2000. 20 May 2004
(9) “Invasion!” Washington, D.C.: The Ecological Society
of America, Summer 1998. 20 May 2004 <http://www.esa.org/education/edupdfs/invasion.pdf>.
(10) Pimentel, David, Lori Lach, Rodolfo Zuniga, and Doug Morrison.
“Environmental and Economic Costs Associated with Non-indigenous
Species in the United States.” Ithaca, New York: Cornell University,
College of Agriculture and Life Sciences, 12 June 1999. Cornell News
Service. 19 May 2004 <http://www.news.cornell.edu/releases/Jan99/species_costs.html>.
(11) Bangsund, D.A. and F.L. Leistritz. “Economic Impact of
Leafy Spurge in Montana, South Dakota, and Wyoming (AER 275).”
Department of Agricultural Economics, North Dakota University, Fargo.
(12) Enger, Steve, et al. “Harmful Exotic Species of Aquatic
Plants and Wild Animals in Minnesota: Annual Report for 2003.”
Ed. Susan Balgie and Wendy Crowell. St. Paul, Minnesota: Minnesota
Department of Natural Resources, 2004. 20 May 2004 <http://files.dnr.state.mn.us/ecological_services/exotics/annualreport.pdf>.
(13) Westbrooks, Randy G. “Invasive Plants: Changing the Landscape
of America: Fact Book.” Washington, D.C.: Federal Interagency
Committee for the Management of Noxious and Exotic Weeds, 1998. Defense
Environmental Network & Information eXchange (DENIX). 20 May 2004
(14) “Biodiversity Threats: Overhunting/Exploitation.”
Biodiversity Project. 20 May 2004 <http://biodiversityproject.org/bdoverhunting.htm>.
(15) “Biodiversity Threats: Environmental Degradation.”
Biodiversity Project. 20 May 2004 <http://biodiversityproject.org/bddegradation.htm>.
(16) “Bald Eagles of the Umbagog Area.” U.S. Fish and
Wildlife Service, Lake Umbagog National Wildlife Refuge. Updated September
2002. 20 May 2004 <http://lakeumbagog.fws.gov/bald%20eagle.htm>.
(17) “Biodiversity Threats: Global Warming.” Biodiversity
Project. 20 May 2004 <http://biodiversityproject.org/bdglobalwarming.htm>.
|This package was last updated on June 2, 2004.