[The economical and evolutionary aspects of the optimal catch of the fish population]

The natural interpretation of population value (internal cost) is used for the common mathematical problem of population exploitation. It is suggested that the population owner--the state--can use internal costs as a tax on fish caught by holders (fishermen). It turns out that such a tax outline make fisherman to establish an optimal long-term strategy of catch. Moreover, if there is several fishermen' the special tax, which makes them to be consistent with common cooperative strategy, can be worked out. According to the proposed hypothesis the changes in internal costs can be used as an adaptive response to the "demand and supply" deformation of the exploited population. The concept of "ecological-economical" niche (habitat + place of sale) was proposed to characterize the exploited population. Computer calculations revealed the specific variant of Gause principle: the co-existing of two similar populations is impossible within single "ecologic-economical" niche. On the contrary, exploited similar populations show co-existence while fish is sailed on different markets.