Invasive species like carp and goldfish disrupt habitats by making it harder for native species to thrive. Explore the following video to see how ecologists at Cootes Paradise in Hamilton, Ontario, have helped restore a marsh.
In an aquatic ecosystem where fish live, humans also influence native fish migration routes in some of the following ways:
Creating dams, weirs, and other systems for water storage or recreational activities changes the amount of water entering and exiting the ecosystem and can remove migration paths.


Installing hydroelectric power like water turbines can hurt fish and plant species if they get stuck in the turbine.
Filling, grading, removing vegetation, building construction, and changes to water levels and drainage patterns make it harder for plants and animals to thrive.
