7.EC.5B.4 Define problems caused by the introduction of a new species in an environment and design devices or solutions to minimize the impact(s) to the balance of an ecosystem.

Any time a non-native species is introduced to a new environment, whether accidentally or purposely, there are consequences to that introduction. When there is a negative impact on the environment, we refer to these organisms as invasive species.

Invasive Species Invasive species can have a major impact on the ecosystem. They can change an entire habitat by occupying the same niche as native species. That in turn causes unnatural competition among organisms. Environmental pressure then increases as the carrying capacity of the ecosystem is reached. Native species that are beneficial to the environment can be crowded out or replaced by the invasive species.

Examples of invasive species There are many well-known examples of invasive species. The zebra mussel and its effect on the aquatic marine ecosystems of the great lakes are well documented. Another example is the red fire ant of South America that has infiltrated the southeastern US and continues to spread.

Responses to invasive species Most governments have programs and regulations that prevent and manage invasive species. Prevention is the first line of defense against invasive species. If preventive methods fail, then a quick response will help reduce the impact on the environment. There are three ways human can respond to invasive species: Physical Chemical Biological

Physical control This would entail creating barriers to prevent new species from entering new environments. This can also include physical removal of new species.

Chemical Control Applying poisons (pesticides or herbicides) to eliminate new species.

Biological Control Uses living organisms to reduce or completely eliminate the invasive species. In some cases the control organism will prey on the invasive species or in other cases the control organism causes disease in the target species.