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Competition for limited habitats and food sources can occur between native species as well as between native and exotic species. For instance, marshes and mudflats in the Great Lakes support many shorebirds, all seeming to feed in the same area, and yet the different species of birds are rarely competing for food since each type of bird becomes best suited for eating a certain type of food through evolutionary processes over more than thousands of years (refer to the figure for the detail). On the other hand, the Sea Lamprey which originally came from the Atlantic Ocean, destroys valuable fish, especially lake trout, by attaching with its sucker-like mouth to suck out blood and body tissues. It upsets the ecological balance by removing top predators, allowing for explosion of populations of smaller fish such as alewives and disturbing the balance of food webs in the lakes. |
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1. Why would birds have greater feeding
success in a marsh where there are many food types available than in a
marsh with only a few kinds of food available?
2. How might the surface on which the birds are feeding affect their feeding success? 3. Identify as many Great Lakes jobs as possible that are affected by invader species. |
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Aquatic Nuisance Species
2. Zebra Mussels 3. Sample Activity: Zebra Mussel 4. A Great Lakes Sea Grant resource list on zebra mussels and other nonindigenous species (Printed material only). To order this material or get more information, please contact Ohio Sea Grant at 614-292-8949. |
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1. The Great Lake Erie
2. Earth Systems - Education Activities for Great Lakes Schools Life in the Great Lakes
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1. Sea Grant Nonindigenous Species Site
(sgnis) http://www.ansc.purdue.edu/sgnis/ 2. Zebra Mussels and Other Nonindigenous Species http://h2o.seagrant.wisc.edu/greatlakes/GLnetwork/exotics.html 3. Aquatics Exotics News http://www.ucc.uconn.edu/~wwwsgo/aen.html 4. Exotic Species and their effects on the Great Lakes http://www.great-lakes.org/exotics.html 5. How to Control the Spread of Waterborne Exotic Species http://www.ofah.org/invsp.htm 6. Aquatic nuisance species in Great Lakes http://www.law.cornell.edu/uscode/16/4711.shtml |