Answer: Hydrosphere
Explanation:
The hydrosphere is the part of earth that comprises of all the water bodies on earth. The water bodies like lakes, sea, ocean, river comes under biosphere.
The aquatic form of life is found in the water. It contains fishes, tortoise, whales, and many more.
The marine ecosystem lie in the water bodies. It starts from the plankton that makes food by the help of the process photosynthesis.
The food produced by the plankton is consumed by other animals found in water.