Stock assessment

Stock assessments provide fisheries managers with the information that is used in the regulation of a fish stock. Biological and fisheries data are collected in a stock assessment.

A wide array of biological data may be collected for an assessment. These include details on the age structure of the stock, age at first spawning, fecundity, ratio of males to females in the stock, natural mortality (M), fishing mortality (F), growth rate of the fish, spawning behavior, critical habitats, migratory habits, food preferences, and an estimate of either the total population or total biomass of the stock.

The following data regarding fisheries activities is collected: the kinds of fisherman in the fishery, commercial versus recreational, and the gear that is used (longline, rod and reel, nets, etc.), pounds of fish caught by each type of fisherman, the fishing effort each kind of fisherman expends, the age structure of the fish harvested by each group of fisherman, the ratio of males to females that are captured, how the fish are marketed, the value of the fish to the different fisherman groups, and the time and geographic location of the best catches. Also in the assessment, geographical boundaries of different stocks or populations are defined. 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 level of overfishing that occurs and restore stocks that have been overfished.