If there are 3000 calories of energy available at the zooplankton, how much energy will there be at the shark?

30 calories of energy

Explanation:

In an aquatic ecosystem, zooplanktons are primary consumer i.e. they feed on primary producers e.g phytoplanktons. They are fed on by smaller fishes e.g tilapia, which in turn is fed on by sharks. Based on this, we have a food chain as follows:

phytoplankton → zooplankton → tilapia fish → shark

From this food chain, it appears that ZOOPLANKTON is a primary consumer while SHARK is a tertiary consumer. Since only about 10% of energy is transferred to each trophic level when organisms feed on one another, if there are 3000 calories of energy available at the zooplankton, the following will be available for sharks:

For secondary consumer = 10/100 × 3000 = 300 calories for tilapia fish

For tertiary consumer = 10/100 × 300 = 30 calories for shark.