Lake Victoria, shown in the population map above, is the largest lake in Africa and is home to fish called cichlids (pronounced SIK-lids). In the 1950s, a new

fish, the Nile Perch, was introduced into Lake Victoria. This map shows the

change in the cichlid population since the Nile Perch was introduced.

Use the map above to answer the questions below.

1. Using a Key In which year was the number of cichlids the greatest?

2. Using a Key How many years did it take for the cichlid population to decrease

by 50 percent?

3. Inferring Relationships Which fish in Lake Victoria do you think is higher on

the food chain

the cichlid or the Nile Perch? Explain your answer.

4. Identifying Trends Based on the rate of decrease of cichlids shown on the map,

what do you think will happen to the cichlid population by 2050? Explain your

answer.