The following resources provide information on the impact of introducing specific new organisms into an existing ecosystem:
For general facts about invasive species, click here.
Zebra Mussels
This reliable site explains the impact of an invasive new species, such as the Zebra Mussel.
Here is more information from the USDA National Agricultural Library.
The University of California, Riverside also provides additional information about the impact of this species.
Rabbits in Australia
The Australian government has a helpful website detailing the negative impact of the introduction of rabbits in that country.
Here is another fact sheet on rabbits in Australia.
Columbia University has a page discussing the impact on European rabbits worldwide.
Purple Loosestrife
This is a reliable site explaining the impact of the Purple Loosestrife plant.
The USDA National Agricultural Library also has information about this plant.
This site explains how to identify the plant.
Additional information can also be found here from nps.gov
Brushtail Possums in New Zealand
The New Zealand Department of Conservation has excellent information about this invasive species.
The Encyclopedia of New Zealand also provide facts about this animal.
National Geographic has a news story about this.