Yes, if we use rotenone, it will kill all the fish. There are 19 species of fish in that lake. If we wanted to bring them back, they would have to be rescued in the meantime. The effect of rotenone will last for a certain time, so the fish have to be maintained somewhere during that time.
Because smallmouth bass are in a number of lakes around that watershed, there's a risk they could be reintroduced after.