 Constant-effort harvesting

Constant harvest effort removes individuals at rate proportional to their current population, with fixed coefficient $E$. Its continuous model subtracts $EN$ from the growth rate, while a discrete model may use $N_{t+1}=g(N_t)-E{N}_t$. This differs from constant-quota harvesting, which subtracts a population-independent amount. A discrete rule must remain nonnegative on its physical state range, or require a separately specified truncation.