What are invasive species?

• Exotic species

• Naturalized species

• Invasive species

Exotic Species

• Exotic in the vernacular means strange, unusual, unfamiliar

Exotic Dancer Exotic carrot

Exotic Species Definition

• Exotic Species

• (Alien, non-indigenous, non-native )

• Introduced New Area

– Outside historic geographic range

• Different Continent

• Different part of the same continent

– Different ecosystem

Different continent

House SparrowDistribution North & Central America

Different Part of a Continent

House Finch

Historic Range SW USA Introduced Long Island NY

Different Part of Continent & Different Ecosystem

Native to tributaries of Pacific Ocean in Asia & North America

Rainbow Trout

Naturalized Species

• Naturalized species:– alien (Exotic) species – establish viable

populations

Dandelion

Ring-necked Pheasant

Chicory – common along roadsides

Naturalized Species

• How many naturalized species occur in the United States?

• What percentage of Illinois’ Flowering plants are naturalized?– Total flora = 3,100 species– 26% (811 species are naturalized)

Why worry about alien species?

• There are about 30,000 alien species in the United States and most of them are beneficial

Toby

Why worry about Exotic (Alien) species?

• Value of Exotic species:– Produce 98% of USA food supply– 500 billion dollars

• Some exotic species become invasive

Invasive Species

• Federal Definition –– “Invasive species” means an alien species whose

introduction does or is likely to cause economic or environmental harm or harm to human health. Executive Order 13112 (Feb. 3, 1999)

• 0.1% percent of alien species that arrive become invasive (10 percent rule)– 10 percent establish (10%) – they are naturalized– 10 percent spread (1%)– 10 percent become invasive (0.1%)

Cost of Invasive species:

• Invasive species cause economic damage:– $123- $137 billion dollar annually in USA

• Agricultural pests – about ¼ of agricultural GNP is lost

• Costs excludes damage to natural ecosystems

How do invasive species cause damage

• Invasive species cause damage by:

– Eliminating indigenous species

– Disrupting ecosystem processes

– Reducing biodiversity

– Cause human health or economic problems

Why are invasive species successful? • Release from enemies

– Natural competitions, parasites, pathogens, predators• Increased competitive abilities (ICA)

• “Vacant niches,” unutilized, or under utilized resources

• Community characteristics– Species richness– Disturbance favors invading species

• Native species often have no natural immunity to introduced diseases – – Dutch elm disease, – Chestnut blight

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Examples of Invasive Species

• Kudzu

• Zebra mussel

• Asian Carp

Kudzu•Introduced from Japan

•Erosion control & Forage

•Rapid growth

•U.S. Soil Conservation Service (1935-1942)

Kudzu over grows trees in SE United States

Occupies 7 million acres Kudzu Distribution in USA

Illinois 16 colonies 440 acres

Alaska Hawaii Puerto Rico Virgin Islands

Zebra Mussel

• Native to streams – (Ural & Volga) entering Caspian sea

• Great Lakes 1988 – ballast water• June 1991 first confirmed sighting in

Illinois River• How did it get into the Illinois River?

Actual size ¾ inch

Chicago River

Des Plaines

Calumet Slag Canal

Illinois Sanitary and Ship Canal

• 1800’s Chicago sewage discharge– Chicago River– Lake Michigan

• Lake Michigan as a drinking water source – 1854 cholera epidemic killed 5.5%– 1860-1900 65/100,000 died annually from

typhoid fever

• Reversed flow of Chicago River (1900)

• Sewage into Des Plaines and Illinois rivers

Chicago River

Des Plaines

Calumet Slag Canal

After 1900

Zebra mussel Impacts• Reduced or eliminated native mussels• Decimated food supply of fish

– Filter out large phytoplankton– Only metabolize green algae –

• Bluegreen algae (Cyanobacteria) – Abundance of zooplankton & plankton eating

fish decreased• Water is clearer• Economic costs• – Clogged pipes

– Attach to boats• Consumed by some ducks & fish

– Not controlled

Transported:

bilge water and on exterior of boats

How do invasive species get here?

• Inadvertently: Foreign transport of goods– Zebra mussel– Asian long-horn beetle– Sea lamprey into Great Lakes– Asian Tiger mosquitoes– Brown tree snake– Dutch elm disease.

• Promoted by state or federal agencies (kudzu, multiflora rose, autumn olive)