Invasive Species Invasive Species: Non native (introduced) organisms that adversely affect ecosystem Introduced intentionally or unintentionally Thrive and become pests Aquatic or terrestrial Examples of Invasive Species 1
Effects of Invasive Species Displace native species Reduce native wildlife habitat Reduce forest health and productivity Disturb ecosystem Degrade recreation areas Impact economy May affect human health Why are Invasive Species so Damaging? No predators Able to out compete native species High reproductive success They can dominate an ecosystem How are Invasive Species Introduced? Intentional Pet Ornamental Hunting/fishing Fur Erosion control Biological control 2
Unintentional Cars Feet Planes Wooden crates Ships/ballast What makes a species likely to be invasive? No predators, disease Fast growth/rapid reproduction They tolerate a variety of habitat conditions They compete aggressively for resources Eucalyptus Native to Australia Imported 1850s: ornamentals, timber, fuel alter soil moisture light availability fire patterns soil chemistry 3
Sudden Oak Death Fungus like organism Accidentally introduced to Europe and North American populations From Asia Bleeding canker on oak tree European (Common) Starling Native to Europe, Western Asia Introduced to N. America, Australia, etc. Damage trees (physically, chemically) Airplane hazard Noisy, dirty, smelly Water Hyacinth Aquatic plant native to South America First introduced to North America in 1884 Fast growing, population doubles in 12 days 4
Blocks sunlight from water Blocks oxygen from water Greatly reduces biological diversity Blocks waterways, making boating, fishing and almost all other water activities, impossible Pacific Northwest Invasive Species Plants: Diffuse knapweed Scotch broom Himalayan blackberry Animals: Atlantic salmon European green crab Gypsy moth American bullfrog 5
Nutria Native to South America Imported to U.S. for fur Released to wild now in 22 states Damage wetlands (by feeding) Damage levees, dams, etc. (by burrowing) Reduce crop yields (by grazing) Spread disease Hawaiian Mongoose Native to India Introduced intentionally to Hawaii 1883 Hawaiian mongoose Polynesian rat 6
Burmese Python Source: pet owners, hurricane hit animal warehouses. thrive in Florida, similar to Asian home Threaten many indigenous, endangered species Zebra mussels Native to the Caspian Sea/Black Sea region of Asia Transported to the Great Lakes 1980s via ballast water Distribution of zebra mussels in the U.S. and Canada, as of 2011. Credit: U.S. Geological Survey cover large areas of lakes and rivers preventing the establishment of other species cover water intakes and clog pipes. 7
Damage infrastructure (power plants) Damage boats/marinas Negative impact on economy Comb Jellies Native to east coasts of North and South America Introduced to the Black Sea in the 1980 s In 1999 invaded the Caspian Sea In 2006 introduced to the North and Baltic Seas. Caspian Sea invasion depletion of the zooplankton by 75%, disrupted the entire food chain. Eat eggs/larvae crucial anchovy species commercially crucial to the fish market one comb jelly thriving population 8
Kudzu Native to Asia Introduced to U.S. in 1876 (ornamental) 1930s used for erosion control, animal fodder Damages plants, infrastructure Fast growing The Kudzu Invasion www.nps.gov Cane Toad Native to Central/South America Sugar cane rats, beetles Imported to Carribbean 1840s Hawaii 1932 Australia 1930s 9
Brown Tree Snake Native to eastern Pacific introduced to Guam after World War II Killed off: 75% Guam s forest bird species 50% lizards Some bat species Major damage to poultry industry Invasive species: how serious a problem are they? costs $125 140 billion/year in the United States 25% of US agriculture gross national product lost 50% of threatened or endangered species due to competition with or predation by non native species. Keep them out Eradicate them Control them Possible Solutions? 10
Python vs. Alligator Nature Video 11