Invasive Species Lecture Objectives: Be introduced to biological invasions Know several examples of invasive species Learn what you can do to stop the spread of invasive species

Definitions: Introduced (non-native, exotic) - species introduced deliberately or accidentally from somewhere else Domestic/Feral (released pets, livestock and game animals) - can spread disease, compete with native species Human commensal or subsidized (out of control natives) - native species that benefit from our land use (disturbance) Invasive species - species that spread subsequent to establishment usually at some cost.

Invasive Species Some introduced deliberately: naturalization societies Shakespeare fans game animals domestic animals Some accidental: ballasts of ships unprocessed wood fruit shipments by-pass natural barriers

Vectors of invasion into ecosystems Intentional Release of Target Species into Containment: - Escapes from Zoos and Botanical Gardens - Farmed Species - Aquaculture - Research

Vectors of invasion into ecosystems Intentional Release of Target Species into the Environment: - Plants for Agriculture - Plants for Forestry - Plants for Soil Improvements - fire suppression, erosion control - Ornamental Plants - Birds and Mammals for Hunting - Biological Control - Released Pets and Pet Trade

Vectors of invasion into ecosystems Release of Non-Target Species (AKA “Accidental” Releases): Contaminants or Hitchhikers with Produce Contaminants or Hitchhikers with Ornamental Plants Contaminants or Hitchhikers with Aquaculture Timber Contaminants of Seed Stock Cars Planes Hitchhikers with Packing Material, Cargo Ballast in ships Hull Fouling Tourists, Luggage Canals

Ballast Tanks

Movement of/ increased exposure to exotic species includes pathogens!! Emerging Infectious Disease – never known before or absent for 20 years Schistosomiasis, AIDS, SARS, etc.

“Forecast and control of epidemics in a globalized world “Forecast and control of epidemics in a globalized world.” Hufnagel et al. PNAS 2004

In 1999, there were more than 50,000 exotic species in the USA

Why study biological invasions? Consequences threaten biodiversity costly widespread Unique opportunities for basic research community ecology animal behavior evolution

Estimated annual costs associated with non-native species: Group costs (in millions) Plants (purple loosestrife, weeds) 34,000 Mammals (feral pigs, rats) 37,000 Birds (pigeons, starlings) 2,000 Fishes 1,000 Arthropods (ants, termites, other pests) 19,000 Mollusks (zebra mussel, asian clam) 1,200 Microbes (plant pathogens, animal disease) 41,000 All organisms over $136 billion per year Source: Pimentel et al. 2000 BioScience

Percentage of threatened or endangered species imperiled by: Habitat degradation and loss - 85% Invasive species - 49% Pollution - 24% Overexploitation - 17% Disease - 3% Source: Wilcove et al.1998 BioScience

Hypotheses for the success of introduced species: Escape from natural enemies predators, parasites, disease Increased competitive ability outcompete native species Pre-adapted to disturbed environments

Characteristics of invasive species general diet and habitat requirements high abundance small body size high reproductive potential (r-strategy) good competitors social / gregarious Generalities would be nice! Make invasion biology a more predictive science.

(different characteristics may be important at different stages) Stages of invasion 1. Opportunity (transport) 2. Establishment 3. Spread (different characteristics may be important at different stages)

What makes certain ecosystems more vulnerable? Diverse, undisturbed communities have few invaders Disturbed habitats: full of invaders Human residential areas: many European species that are commensal with humans Islands: little history with competitors, predators, parasites, or diseases

Birds Mute swan European starling Monk Parakeet

European Starling First successful introduction was 60 European starlings released in Central Park, NY. in 1890, by fans of Shakespeare competes with bluebirds, woodpeckers slippery sidewalks

The House Sparrow was introduced into Brooklyn, New York, in 1851. Competition from the House Sparrow for cavity nests can cause decline of some native species.

Insects In 1956, African Honey Bees were imported into Brazil Africanized Bees In 1957, 26 African queens escaped Reached US in 1990 More aggressive than European Honey Bees, have killed 1,000 people Impact honey and pollination industries

Insects Crop pests boll weevil, corn borer Culex mosquitos carry avian malaria and pox driven 20 Hawaiian bird species extinct Adult boll weevil

Insects Asian Long-horned Beetle attacks and kills many native trees Found in Chicago in 1998

Insects Gypsy moth Introduced in 1860s Originally brought to the US for silk production now defoliates entire forests

Reptiles and Amphibians Cane toad – native to Central and South America Introduced world-wide to control insects milky secretions are highly toxic. Kill dogs, cats and small native animals

Reptiles and Amphibians Brown Tree Snake Introduced to Guam via cargo transported by U.S. military ships during World War II On Guam wiped out 9 of 13 indigenous bird species

Mammals Goats and pigs in Hawaii wiped out native plants Horses in Grand Canyon causing erosion Game animals “Texotics” “Texotics” Oryx Photo: Dr Mike Hill

Plants Kudzu Introduced into the U.S. in 1876 at the Philadelphia Centennial Exposition promoted as a forage crop and an ornamental plant until 1953 kills other plants by smothering them under a solid blanket of leaves

Plants Garlic mustard poses a severe threat to native plants and animals garlic mustard outcompetes native plants by monopolizing light, moisture, nutrients, soil and space. Buckthorn Not as good food for herbivores as many native species

Giant snakehead (Channa micropeltes) found in Wisconsin in 2003 Fish Northern Snakehead (Channa argus) Found in Maryland in 2002 Giant snakehead (Channa micropeltes) found in Wisconsin in 2003

Laurentian Great Lakes www1.ncdc.noaa.gov/pub/data/images/ great-lakes-ice-avhrr.gi Superior Mills et al. 1993 Over 140 exotic species Huron Many fish species were (and continue to be) released intentionally Michigan Ontario Erie Many other exotics have entered the lake accidentally: Canals Escape from captivity Ballast water Bait buckets, live wells and gear

19 locks, filled and emptied by gravity

Welland Canal Niagara Falls was the major obstacle to an uninterrupted waterway Begun in 1829

Sea Lamprey (Petromyzon marinus) Invaded the Great Lakes after the opening of the Welland Canal Devastated native fish stocks, especially lake trout

Other fish (>25 species) Round goby (1990) (Neogobius melanostomus) Ballast water Alewife (1873) (Alosa pseudoharengus) Canals Chinook salmon (1873) (Oncorhynchuys tshawytscha) Deliberate release Coho salmon (1933) (Oncorhynchus kisutch) Deliberate release

Exotic Crustaceans (>6 species) Bythotrephes cederstromi (1984) Ballast water Cercopagis pengoi (1998) Ballast water

Exotic mollusks (> 14 species) Quagga mussel (1990s) (Dreissena bugensis) Ballast water Asiatic clam (1980) (Corbicula fluminea) Aquarium release

ZEBRA MUSSEL — Dreissena polymorpha Found in 1988 in Lake St. Clair (Lake between Huron and Erie, just off of Detroit, MI). Up to 70,000 individuals per m2 Likely came to North America in ballast water

One of the most expensive exotic species Will biofoul and restrict the flow of water through intake pipes (drinking, cooling, processing and irrigating water) Also attaches to boat hulls, docks, locks, breakwaters and navigation aids, increasing maintenance costs and impeding waterborne transport.

Can attach to hard surfaces Characteristics of zebra mussels: Can attach to hard surfaces They have a free-living planktonic larval stage— veliger Females can produce 40,000 veligers These are typical characteristic of marine species

Veligers are easily transported in bait buckets and livewells and anywhere else water collects Adults can attach to hulls and survive outside of water for several days. Cover most hard surfaces

Negative effects on native clams Zebra mussels cover them and prevent them from feeding and moving

Plants (> 59 species) Purple Loosestrife (early 1800s) Lythrum salicaria Eurasian Watermilfoil (1881) Myriophyllum spicatum

Never dump bait buckets!! How to prevent the spread of aquatic nuisance species? Never dump bait buckets!! Before leaving site, inspect gear, boats and trailers for exotics Empty all water before leaving site Rinse your boat and equipment with high pressure hot water, especially if moored for more than a day Let equipment dry for several days (does not work for species with resting eggs)