Fish Population Dynamic and Stock Assessment

1.5.4. Fisheries data

(iv) Fisheries data

The fisheries data include the kinds of fishermen in the fishery, commercial versus recreational, and the gear used, amount of fish caught by fishing, age structure of the fish sex ratio, how the fish are marketed, the value of the fish to the different fishermen groups, and the time and geographic location of the best catches. Further, geographical boundaries of different stocks or populations are also defined in the assessment.

From the combined biological and fisheries data, the current status and condition of the stock is defined and managers use this assessment to predict how in the future, stocks will respond to varying levels of fishing pressure. Ultimately, managers want to reduce the levels of overfishing that occurs and restore stocks that have been overfished.

For fish stock assessment studies, the growth of the fish and its age form the most necessary primary data. The age and growth data of a stock goes as input parameters for the estimation of growth parameters and mortality parameters. These two parameters along with selection parameters goes as input data for prediction models which will be dealt in the coming chapters.

Fish stock assessment should be made sex-wise / stock-wise separately. The results should be subsequently pooled for optimization of assessment.