Invasive Invasive SpeciesSpecies

What is an Invasive Species?What is an Invasive Species?

►Plants, Animals or Micro-organisms that Plants, Animals or Micro-organisms that are introduced into an environment to are introduced into an environment to which it is not native and causes harm.which it is not native and causes harm.

►Cows and some ornamental flowers are Cows and some ornamental flowers are not native to all areas but are not not native to all areas but are not invasive because they do not cause invasive because they do not cause damage. damage.

Brown Tree SnakeBrown Tree Snake► Came to US on ships from Came to US on ships from

Guam after WWIIGuam after WWII► Kills off species with its Kills off species with its

tremendous appetitetremendous appetite

Examples of why species are Examples of why species are introduced to a new areaintroduced to a new area

►Some plants used to control soil erosionSome plants used to control soil erosion►Ornamental plants used in landscaping Ornamental plants used in landscaping

around homesaround homes►European birds were brought to the US European birds were brought to the US

to make colonists feel at hometo make colonists feel at home►Fish used to stock ponds/streams for Fish used to stock ponds/streams for

game fishinggame fishing►Exotic pets escaping or being releasedExotic pets escaping or being released

Indian MynaIndian Myna

►Native of IndiaNative of India► Introduced to Introduced to

world to world to control insectscontrol insects

►Takes over Takes over ecosystems ecosystems and reduces and reduces biodiversitybiodiversity

How do Invasive Species Enter a How do Invasive Species Enter a New Environment?New Environment?

► Illegal or legal importingIllegal or legal importing►Exotic PetsExotic Pets►TravelersTravelers►Weather PatternsWeather Patterns►TidesTides►Water CurrentWater Current►Migratory AnimalsMigratory Animals

An Invasive Species of PAAn Invasive Species of PA

►Zebra Mussel Zebra Mussel

Accidentally released by boatsAccidentally released by boats

Eats native organisms’ food sourcesEats native organisms’ food sources

Clogs pipes and attaches itself to boats Clogs pipes and attaches itself to boats and animalsand animals

Zebra MusselsZebra Mussels

Another PA Invasive SpeciesAnother PA Invasive Species►Hemlock Wooly AdelgidHemlock Wooly Adelgid

Small insectSmall insect Accidentally introduced from Accidentally introduced from

Japan/ChinaJapan/China Kills Hemlock trees which are used Kills Hemlock trees which are used

for providing habitat and shading for providing habitat and shading streams for fishstreams for fish

What is effected by the Invading What is effected by the Invading Species?Species?

►Biodiversity Biodiversity ►AgricultureAgriculture►ForestsForests►Lakes, Ponds, Rivers, Streams, OceanLakes, Ponds, Rivers, Streams, Ocean►EnvironmentEnvironment►HealthHealth►EconomyEconomy

Why are they harmful?Why are they harmful?

►They have no natural enemiesThey have no natural enemies►Reproduce quickly and freelyReproduce quickly and freely►Use natural resources intended for the Use natural resources intended for the

native organismsnative organisms►Destroy CropsDestroy Crops►Alter the Food ChainAlter the Food Chain►Force out native speciesForce out native species