You are presented with a simple food chain:

phytoplankton-zooplankton-planktivo rous fish-small predatory fish-top consumer fish.

Use your understanding of how energy is lost at each trophic level and determine what the amount of phytoplankton must be to produce 10 kilograms of top predator fish.

Mass of phytoplanktons will be   Kg

Explanation:

As we know

Kg of body mass is equal to Joules

So energy contained in kg of fish which lies at the top of the food chain is

Now energy with small predatory fish be X

Let the energy with planktivorous fish be Y

Let the energy with zooplankton be Z

Let the energy with phytoplankton be A

Mass of phytoplanktons will be

Mass of phytoplanktons will be   Kg