Lack of assessment methodology for culture-based fisheries has been identified as a major problem in the development of fisheries. The optimal stocking density, size at harvesting and fishing mortality are interrelated. Over-fishing is equivalent to under-stocking, and overstocking is equivalent to under-fishing. This model of quantitative population dynamics for culture-based fisheries increases long-term fish production and harvesting efficiency through optimizing stock and harvesting regimes. It is useful even in situations where data is insufficient for a quantitative assessment. This technology can be described as a software package of spreadsheets, which enables management practices in culture-fishing through modelling the population dynamics. The spreadsheets can easily be adapted to particular culture systems.