Some fish that do thrive there are particularly at risk from introduction of new species.

The past introduction of several exotic species to the park is an additional human influence on the area.

The introduction of foreign species is almost always a burden on the affected ecosystem.

Space can provide for an unlimited increase in population and potentially the introduction of new human biological species.

The bill also would require a report on how inspectors can prevent the introduction of alien species.

The introduction of invasive species may have environmental, economic, and ecological implications.

In the West, where dams and the introduction of exotic species are common, the situation is particularly acute.

The arboretum was created 1900-1910 for experimental introduction of foreign species into France.

This non-native species introduction appears to be the largest threat in the southern California area.

We certainly need to do far more to stop the unwitting introduction of non-native species.