Question

In a marine ecosystem, phytoplankton produce 500,000 kJ of energy daily. Zooplankton absorb 40,000 units of energy from the phytoplankton. There is 20,000 kJ of energy used in respiration by the phytoplankton. There is 5,000 kJ of energy absorbed by the small fish and 400 units of energy absorbed by the large fish.

a) Determine the GPP and NPP of this ecosystem.
b) Calculate the percentage of energy transferred to the zooplankton.
c) Calculate the percentage of energy lost in transfer to the zooplankton.
d) Calculate the percentage of energy transferred from the zooplankton to the small fish.
e) Calculate the percentage of energy lost in transfer from the zooplankton to the small fish.
f) Calculate the percentage of energy transferred from the small fish to the large fish.
g) Calculate the percentage of energy lost in transfer from the small fish to the large fish.

Answer 1

The percentage of energy transferred from zooplankton to small fish is 12.5%, from small fish to large fish is 8%, and the percentage of energy lost in transfer from small fish to large fish is 92%.

Step-by-step explanation:

To calculate the percentage of energy transferred from one trophic level to another in a marine ecosystem, we use the figures provided and apply the following formulas:

• d) Percentage of energy transferred from zooplankton to small fish = (Energy absorbed by small fish / Energy absorbed by zooplankton) × 100
• f) Percentage of energy transferred from small fish to large fish = (Energy absorbed by large fish / Energy absorbed by small fish) × 100
• g) Percentage of energy lost in transfer from small fish to large fish = 100 - (Percentage of energy transferred from small fish to large fish)

Applying these formulas:

1. d) Percentage of energy transferred from zooplankton to small fish = (5,000 kJ / 40,000 kJ) × 100 = 12.5%
2. f) Percentage of energy transferred from small fish to large fish = (400 kJ / 5,000 kJ) × 100 = 8%
3. g) Percentage of energy lost in transfer = 100 - 8 = 92%

Note that here we converted the units of energy absorbed by large fish from 'units' to kJ assuming they are equivalent to remain consistent with other energy measurements provided.