What is an exotic species?
organisms that are not native to an ecosystem. Something that is introduced to an ecosystem for a reason.
example: saalmon in Lake Michigan for fishing
What is an invasive species?
exotic organisms that adersely impact the habitats they invade.
can be economic, environmental, or public health perspective
Why does it matter if an ecosystem is distrupted?
- provides goods: timber, water, food, etc.
- provides services: ex. wetlands filter toxic substances
also maintains population balances
What are some examples of some invasive species?
- Water hyacinth: covers entire lake/pond so other organisms can't live there
- Brown tree snake: causes extinctions of other vertebrates, poweroutages and lack of exporting goods in Guam
- Formosan Subterranean Termite: rapid wood consumption rate because of large numbered populations
- Other examples:
- wild pigs, fragmities, ferrel cats, blackberry, pigeons
Why is Great Lakes region an invasive species hotspot?
- Gateway for importing/exporting goods
- young lakes
What are some Great Lakes region invasive species and their impacts?
- Zebra muscle: filter feeders, eat algae and make water cleaner but cling on pipes and other things that can cause clogs and backups
- Round goby: eats eggs of important sport fish
- Alewif: get washed up on shore after spawing causing decrease in beachgoes
- sea lamprey: parasite on fish with sharp razor jawless mouths.
- Purple Loosetrife: will overtake all other plants in wetlands and cause major problems
- Gypsy moth: has ability to eat all leaves in forest
- Emerald ash borer: lay their eggs in between bark and tree. eggs hatch and burrow tunnels through tree and end up killing it.
How did invasive earthworms get here?
- Big ships: europeans used soil to balance ships their soil got dumped onto our soil
- Root bulbs: plant root bulbs from other locations got transported here and contained earthworms in the dirt with it.
How do invasive earthworms spread?
- Being used as bait
- cocoons get stuck in the giant treads of trucks and tractors and get moved to a different location
What are the impacts that invasive earthworms have on the forest?
- Root disruption
- decreased seedling recuitment
- reduced ground cover
- reduce plant diversity
- facilitates invasive plants
- alters nutrient cycle