Direct or actual count method of estimation of population

DIRECT OR ACTUAL COUNT METHOD OF ESTIMATION OF POPULATION

  • But for the limitations in its applicability, this method is the simplest and the best for accuracy. The method consists of counting all the individuals in a population. This is achieved in a number of ways:
    • The entire body of water is drained, the individuals recovered and counted
    • The water body is intentionally poisoned and individuals counted
    • For migrating schools, counting of individuals moving up or down the stream is made, (when the population passes a vantage point such as a bridge, a fish ladder etc.) by eye or by photography from aeroplanes
    • Individuals are caught by angling, trapping or netting repeatedly in order that a point of “no-return” is reached and all the individuals are counted
    • Counting of individual of a water body is made by sampling. Some sections of the water body are selected at random and enclosed with nets, and area-density for the whole is determined on the basis of the representative samples.
Last modified: Tuesday, 8 March 2011, 7:45 AM