Question of the Day: 1.Are humans an invasive species? Give an example of why or why not. 2.Name two invasive species affecting the Great Lakes. 3.What negative impacts are invasive species having on the Great Lakes ecosystem?
Bioinvasion Species introduced to a new area Due to either direct or indirect human actions rida-16-foot-python-deer-photos- pictures_n_ html
Non-native Species Species that are introduced to areas beyond their historic natural range – Alien – Exotic – Foreign – Introduced – Non-indigenous
Invasive Species Aggressive Spread over large areas Disrupt natural ecosystems Interfere with human activities
Invasive Species After destruction of habitat by human activities, invasive species are the worst threat to endangered species and biodiversity
Starlings European starling imported from England in 1890 Intentionally released in Central Park – Literary societies believed America should have all birds mentioned in Shakespeare Now most common bird Source: Ross Sea Info
Starlings Congregate in large flocks Drive native birds from nesting grounds Compete with native birds for food – Omnivores – insects as well as farm crops Droppings contain fungus that causes histoplasmosis – a respiratory disease in humans
Exotic Newcastle disease Fatal viral disease that affects ALL birds Believed to have been introduced to US by parrots from South America – 1971 outbreak affected 12 million birds, all had to be destroyed – Cost $56 million Except for 3 years, detected every year since 1974
Problems with Importing Birds Big demand for parrots in North America, Europe, and Japan Combined with habitat loss, taking of birds resulting in population declines Illegally imported birds can also carry diseases without seeming sick – Affect poultry and native birds
Plants Hundreds of plants brought to US intentionally – Food – Medicine – Ornamental Others brought accidentally in grain, straw, or soil Changes landscape
Purple Loosestrife Introduced to US in 1800s Valued for medicinal and ornamental purposes Still widely used for ornamental reasons Source: National Park Service
Purple Loosestrife Can produce millions of seeds a year Also reproduces with rapid growth of underground stems Eliminated native plants from 1.5 million acres of wetlands Displaces food supply of many wild animals Few animals feed on it
Purple Loosestrife Several states prohibit growing, selling, and transport US Dept. of Agriculture authorized introduction of two insects that only eat loosestrife for biological control
Problem with Ballast Water Water taken in by ships for stability – Necessary in commercial shipping Often dumped when ship reaches destination 1981 study of ballast water – Ballast water of 30 ships examined – Found living organisms in every tank
Zebra Mussel Native to Caspian Sea Made way to Western Europe by Industrial Revolution Source: Minnesota Sea Grant
Zebra Mussel 1988 – spotted in Lake St. Clair (between Lake Huron and Lake Erie) – Came from European freighter Mature female can produce 30,000 – 40,000 eggs a year – Population explosion Spread into all of the Great Lakes and connected bodies of water
Zebra Mussel May damage fishing industry – Completely cover surfaces fish use for spawning Filter algae and other microscopic organisms from water Have improved water quality – More light penetrates deeper in water, more plant growth – Removed some chemical pollutants
Zebra Mussel Huge expense for cities and industry that use water from Great Lakes – Clog water intake pipes of industrial and power plants Source: EPA
Chestnut Blight First seen in 1904 in New York Zoological Park Came from trees imported from Asia Source: Oregon State Government
Chestnut Blight Fungus that grows beneath bark – Cuts off flow of nutrients and water – Doesn’t kill roots – Infects new sprouts Spores spread by wind and carried by insects and birds By 1950 had spread throughout chestnut’s natural range
Dutch Elm Disease First reported in Ohio in % of trees lining streets of some towns were elms Came from France with elm logs sent to Ohio Source: Wichita State
Dutch Elm Disease Fungus that produces a poison that clogs sap- carrying tubes of American elm Carried by European elm bark beetle Tree surgeons trying to save remaining elms – Injecting fungicide into tree and soil – Removing dead branches to prevent beetle from breeding in soft wood
Gypsy Moth Brought from France to Massachusetts in 1860s – Hope to breed better silk-producing insects Larvae escaped Source: Michigan Nature Association
Gypsy Moth By 1902 spread through New England Continue to spread south and west at rate of 13 miles a year Have been spotted in California, Utah, Oregon – Transported by tourists Federal law requires movers to check for moths before moving outdoor equipment
Gypsy Moth Larvae feed on as many as 500 species of plants Larger trees die because they don’t have leaves – Forest canopy opens – More light, low-growing plants increase – Cover for rabbits, turkey, grouse – Food shortage for squirrels – no acorns or other nuts – Deer have more food
Gypsy Moth Millions of acres have been sprayed with pesticides Some animals have learned to eat them
Africanized Bees 1956 – geneticist imported African queen bee to Brazil – Hoped to produce a more productive bee better suited to tropics 26 Africanized bees escaped – Began to extend northwards at rate of 200 miles a year – Arrived in Texas in 1990 Source: USGS
Africanized Bees Slightly smaller than European honeybee Not the “killer bee” that people think More defensive than European bee – React more quickly – Many more respond – Follow intruder 8-10 time further – Sting 8-10 times more often
Africanized Bees Africanized bees’ behavior make it more difficult for beekeepers to manage hives Use more of the honey they produce than European honeybees European honeybees (most bees in US) were introduced 400 years ago
Mediterranean Fruit Fly (Medfly) Native of tropical Africa Serious pest in Mediterranean area and other countries Attacks more than 250 varieties of fruits, vegetables and nuts
APHIS US Dept of Agriculture restricts items brought to mainland US from other countries as well as Hawaii, Puerto Rico, and the Virgin Islands Animal and Plant Health Inspection Service (APHIS) responsible for guarding against foreign plants and animals
APHIS Required to declare meats, fruits, vegetables, plants, animals, and plant and animal products brought to the country Potted plants and soil not allowed to be imported – soil might have pests and disease Fruit and lumber go through inspection and testing procedures in quarantine
Know Before You Go You should know import/export restrictions for countries you are visiting as well as the US USDA has publication “Know before you go” listing US regulations
Know Before You Go Until recently, taking a dog to England required a six month quarantine to ensure it didn’t have rabies – England doesn’t have rabies New regulations now require pets to have passport that certifies pet has a microchip to ensure identity, vaccination against rabies, and treatments for ticks and tapeworms