Answer is 14.29 % death rate
Step by step
The death rate will be the years % decrease in the population of fishes.
Starting population of fish = 7000 fish
Death of fish for the year = 1000 fish
Population death rate for the year = dead fish for that year divided by starting population of fishes
Yearly death rate = 1000/7000
= .1429
Change to percent by moving the decimal two digits to the right
= 14.29%