Marine Biology

 Food chain

The biotic components of any ecosystem are linked with each other by food. This food relationship with other organisms is termed a food chain. In any ecosystem, the primary producers form the food source for the primary consumers or herbivores, which will form food source to the secondary consumers or carnivores. The sequence of eaters being eaten is called food chain. A simple food chain may start with microscopic green algae. Microscopic zooplankton will serve as food for the small fishes.

  Primary producers                         Primary consumers                                   Secondary consumers

(Phytoplankton and macroplants)  (Zooplnkton and herbivorus fishes)     (Small fishes and predatory fishes)

In a simple food chain, there are more than two trophic levels and the energy is transferred from one level to another. This transfer of energy from one trophic level to another is termed energy flow. The flow of energy in the food chain is unidirectional and never flows back. When the energy is passed on to the next trophic level, the efficiency is lost from one level to another.