For the differential equation that models fish populations with harvesting,we saw that if...

For the differential equation that models fish populations with harvesting,

we saw that if C > kN/4 the fish population will become extinct. If the fish population falls to near zero because the fishing level C is slightly greater than kN/4, why must fishing be banned completely in order for the population to recover? That is, if a level of fishing just above C = kN/4 causes a collapse of the population, why can’t the population be restored by reducing the fishing level to just below C = kN/4?