1. 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

2. Invasive Species Sometimes called Non-native Alien Non- indigenous

3. 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

4. Invasive Species Invasive species can be plants, animals, and other organisms (e.g., microbes). Introduced to new environments by globalization

5. Steps to Becoming Invasive Species must be … 1. Introduced 2. Established 3. Invasive

6. 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

7. 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 garden trade – sale of aquatic animals and plants for ponds and water gardens

8. 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

9. How Do Species Become Established? Depends on the interactions among these factors: 1. Propagule pressure 2. Natural History of the introduced species 3. Susceptibility of environment to new species

10. 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

11. 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

12. Natural History Origin Diet Growth rate Habitat conditions Reproductive behaviors Above: Example of Species’ Natural History Summary

13. 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

14. 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

15. 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)