How can using a dam as a source of freshwater also harm wildlife?

Answer 1

Ecosystem Modification

Changing a habitat from a river to a lake can have many negative effects on fish. The presence of the dam may also change the way predators and prey interact. In many cases the negative effects of these changes are greater than the direct effects of the dam itself.

Loss of Habitat

Most salmon are adapted to living in rivers so changing their habitat to a lake often has negative consequences on their life cycle. This is especially true for activities such as spawning.

Predator/Prey Relationships and Non-native Species

Changes to the river caused by dams and reservoirs may actually benefit predators while making salmon more vulnerable. Fish delayed while trying to pass a dam are often the targets of predators. Changes to habitat may benefit predator species allowing them to increase their numbers. For example, the northern pike minnow, a native predator, prefers slow water habitat.

Examples:

Sturgeon

• Dams divide rivers, creating upstream and downstream habitats. But migratory fish, such as sturgeon, depend on the whole river. Dams block their ability to travel back upstream. Sturgeon also rely on temperature triggers and shallow areas for reproduction. Because dams change how rivers flow, the water temperature and natural conditions also change. This prevents sturgeon from mating and/or hinders the development of fish larval.

Egrets

• Egrets, along with other wetland birds, depend on healthy river systems for food and shelter. They make their nests in the steep banks of rivers or floodplain thickets. Dams prevent the natural highs and lows of rivers They can also reduce the breeding ground of migratory fish—a key food source for egrets—and cloud the waters, making it harder for egrets to spot their prey.

Answer 2

Dams displace existing habitats.

Answer 3

Dams can collect topsoil during floods, Apex