This is a growth problem and and will utilize the following formula:
A=P(1+r)^y
A=200(1+2.3)^1 for the first year A = 660 fish
A=200(1+2.3)^2 for the second year A=2178, However Given the lakes capacity of 1600 fish, it will not reach this amount. It will reach capacity during the second year and be at 1600.