Answer:
The global food web includes a major part as marine ecosystem. It produces food for consumers in the biosphere.
The plankton make food by trapping sunlight from the sun. The carbon dioxide in the water is also used during the process of photosynthesis.
These plankton are eaten up by primary consumers and human beings and big fishes are secondary consumers.
Sea food are major part of food web and food chain as they serve as food for many people.