Food is one of the important requirements for the
existence of any living organism. In the oceans the food
production takes place at two levels - primary level and
secondary level. Among these, the food is synthesised only at
the primary level in the form of carbohydrates. The micro and
macrophytes in the seas are responsible for primary production.
The zooplankters carry out the important function of converting
plant matter into animal substances which forms the food for
fi~ha nd other higher animals
