In the fall of the year, the leaves of some trees change color as chlorophyll begins to break down. what impact does this have on the role of the mitchondria in the cells

As the chlorophyll breaks down less energy will be required by the leaf to carry out the process of photosynthesis so lesser amounts of atp will be produced by the mitochondria at the same time since the amount of store chemical energy in the plant will decrease the amount of energy being released by the   mitochondria as well resulting in an overall lower production of atp.

True, for example the gulf of mexico is surrounded by the us and spain& mexico.