The Answer IS AEROBIC RESPIRARTION because it’s The breakdown of food to create energy in the presence of oxygen.
That would be myology. Myology is the study of the muscular system, wlong with its nature, structure, functions and diseases. It mainly deals with the three types of muscles found in the human body: skeletal muscles, smooth muscles, and cardiac muscles. Muscles are also categorized depending on whether or not they are voluntary or involuntary. Myology is concerned with the study of all this and much more.
It’s caused by the different density’s in the water
Well, considering if the deer and the hawk have a direct predator prey relationship, where the deer are the prey, then the hawk population will also drop quite a lot, unless they have some other major food sources, but chances are they'll still drop.
If it's NOT a direct predator prey situation, for example: The deer happen to eat something that the hawks also eat, or the deer are prey for something the hawks eat:
If the deer eat something the hawks eat, by them dropping it means there will be more food supply for the hawks, meaning as the deer population drops, the hawk population will go up.
If the deer are PREY to something the hawk eats, then by there being less deer, then whatever the primary consumer of the deer is will also drop. If the hawk eats that predator, then there will be less of those predators, and less prey, meaning the hawk population will still drop
You were most likely given a food web to look at. Seeing how you didn't post that, I just gave you the only 3 situations that could happen.
~Hope this helps!