Aquatic ecology and Biodiversity

Unit 2- Ecosystem ecology

2.3. 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. A simple food chain may start with microscopic green algae. Microscopic zooplankton will serve as food for the small fishes.
Food chain is the sequence of the eaters being eaten is called food chain. The biotic factors of the ecosystem are linked together by food. The various steps in the food chain is called “Trophic level”. Trophic level is simply feeding level at each level. Owing to repeated eating being eaten, the energy is transferred from one trophic level to another trophic level. This transfer of energy from one trophic level to another is called energy flow. There are three trophic levels of food chain in upwelling areas and five in marine environments. Normally four trophic levels of food chain in a pond ecosystem. Shorter the food chain greater the energy tranfer. Energy flows in an ecosystem through the food chain in a unidirectional and at steady state.