Common carp (alien)
Naturally occurring in Central Asia and parts of Europe, common carp are now found in many parts of the world.
Like most other alien species, they are hardy and can tolerate a wide range of conditions, thriving in dams and large turbid rivers.
Carp stir up sediments when they feed, making the water cloudy, and sometimes stirring up water low in oxygen.
This can affect plant growth, as well as changing habitat quality for indigenous fish and other aquatic species that have adaptations for hunting or feeding in clearer waters.
Their destructive feeding habits have led to carp being viewed as pests by many conservationists.