When a fish is floating motionless below the surface of a lake, what is the amount and direction of the force the water is exerting on it?

Buoyant force which is equal in magnitude to the fish's weight

Explanation:

A fish floating motionless below the surface of a lake, is an equilibrium position with the water.

Hence, upward force must be equal to downward force.

The downward force is due to fish's weight while the buoyant force is the upward force due to force of the water.