Answer:
the expected decline in largemouth bass is 3,000 kg.
Option d) 3,000 kg is the correct answer.
Explanation:
Given the data in the question;
In 2016, there was 600,000 kg of zooplankton in the lake.
In 2017, an accidental runoff of insecticide near the lake caused a 50 percent decline of the zooplankton population in the lake.
Now,
The remaining mass of zooplankton after the 50% decline will be;
⇒ 600,000 kg zooplankton × 50%
⇒ 600,000 × 50/100
⇒ 300,000 kg of zooplankton
Now, with 10 percent trophic efficiency; smaller fish directly feed on zooplankton; decline in smaller fish mass will be;
⇒ 300,000 kg × 10%
⇒ 300,000 × 10/100
⇒ 30000 kg
Finally, with 10 percent trophic efficiency, largemouth bash directly feed on smaller fish, so the expected decline in mass of largemouth bash will be;
⇒ 30000 kg × 10%
⇒ 30000 kg × 10/100
⇒ 3,000 kg
Therefore, the expected decline in largemouth bass is 3,000 kg.
Option d) 3,000 kg is the correct answer.
