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Freshwater Invasive Species. Notes adapted from the Encyclopedia of Inland Waters “Invasive Species” by R P Keller and D M Lodge, University of Notre Dame, Notre Dame, IN, USA. Invasive Species. Sometimes called Non-native Alien Non- indigenous . Invasive Species.
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Freshwater Invasive Species Notes adapted from the Encyclopedia of Inland Waters“Invasive Species” by R P Keller and D M Lodge, University of Notre Dame, Notre Dame, IN, USA
Invasive Species Sometimes called • Non-native • Alien • Non- indigenous
Invasive Species • When a new species enters an ecosystem that is not its original home • The species is considered “invasive” when it causes harm • Economic or environmental harm • Harm to human health
Invasive Species • Invasive species can be plants, animals, and other organisms (e.g., microbes). • Introduced to new environments by globalization
Steps to Becoming Invasive Species must be … • Introduced • Established • Invasive
How are Species Introduced? • They are transported from their home to a new place • This can be done on purpose- intentionally Or • This can be done on accident - unintentionally
Intentional Introduction • Stocking waters to establish new food resources or opportunities for sport fishing • Aquaculture – farming of water organisms for food • Aquarium trade – sale of aquatic animals (pet store) • Water gardentrade – sale of aquatic animals and plants for ponds and water gardens
Unintentional Introduction • Canals- species can move through these waters way which were made by man • Fouling Organisms - organisms hitch a ride on a trade ship in the ballast tank or on the ships hull • Contaminants – small organisms can be transported on larger organisms through aquarium trade or water garden trade
How Do Species Become Established? Depends on the interactions among these factors: • Propagule pressure • Natural History of the introduced species • Susceptibility of environment to new species
Propagule Pressure • The number of organisms released into a new habitat • The more individuals released over time, the more likely that a species will become established
Propagule Pressure • If too few individuals are released at the same time • they many not be able to reproduce enough offspring to become established • they will die out
Natural History • Origin • Diet • Growth rate • Habitat conditions • Reproductive behaviors Above: Example of Species’ Natural History Summary
Ecological Impacts What are the consequences of bringing this species to Lake Michigan? How does the invasive species impact the native species? Does it … • Compete for resources • Hunt and eat native species • Bring infectious pathogens • Decrease water availability
When does it become INVASIVE? • When it causes harm • Kills or hurts native species • Costs communities money to manage • Reduces recreation • Loss to fishermen • Loss of food resources to farmers • Introduces parasites and disease to humans
Asian Tiger Mosquito • Native to South-East Asia; • Currently in 28 countries • Aquatic Larval Stage – spread in water • Large, aggressive, spreads many diseases • Spread and transmission of West Nile Virus • Spread by recycling old tires (globalization)