I think if the whale population decreased the surface fish populations would decline due to reduced populations of algae. This can be simply explained by the fact that, if the whale population is decreased, it means that the nitrogen rich feces that is supply nutrients to the algae would also decrease and therefore decrease the population of the algae and as a result the population of of the surface fish would also decline.
A tropism.
A plant movement to a light stimulus is a phototropism.
A plant movement to water stimuli is a hydrotropism.
etc. etc. :)
When exercising is when the lungs work the hardest because you're using a lot of muscles and are running around and are using force in your body so the lung works really hard to make sure the body gets enough air while working out.
