One important component of almost all theoretical models in fishery is a fish transfer function. However, most of the current fish transfer functions have significant shortcomings. This paper contributes to the literature on fishery management by showing some of shortcomings of commonly used fish transfer functions and proposing a new fish transfer function that is more appropriate to model net amount of fish transfer from one marine area to another; and applying the proposed transfer function in an optimal harvest problem to assess the economic payoff from a switching reserve versus a fixed marine reserve. The findings indicate that a switching marine reserve appears to provide fishers with higher economic benefits than a fixed marine reserve. The payoff gain from a switching reserve appears to increase when the fish move less because of bio-ecological and territorial factors that impede the fish dispersal between marine areas.