Current+&+Velocity7

Current & Velocity The streams current affects many forms of aquatic life and materials. In the picture above, the current is very strong and fish cannot live in these rough waters. The only marine life that can live in these freshwater river rapids are mollusks. While fish cannot live in this water, many streamline fish (such as trout) will swim through these currents in order to spawn. Currents, unlike oceans, flow in one direction and carry loads and substances to the life living in the waters. The substances are nutrients. This is one way fish and other aquatic animals are able to receive nutrients besides food. Fish like bends in rivers and streams because of the increased velocity and because there is more dissolved oxygen and it is also colder where the current is swifter. Here these trout are acting as if this water pipe is a current in a river and are using their migratory instincts to travel to a place where they can spawn. Humans affect currents by putting dams in and changing how the river runs.