Population estimation Fisheries
Population estimation Fisheries Introduction Estimates of population size play a vital role in many fisheries management decisions. The numbers of fish in a stock are used to identify influences of environmental factors, human exploitation, and ultimately to identify the effectiveness of management strategies. (Van Den Avyle & Hayward 1999) The three most common methods of population estimation among biologist are sample plots, mark and recapture, and removal. Counts on sample plots is based on the principle that an estimate of population size can be obtained by determining the average density of animals per unit area and multiplying its value by the total area covered by the population. This procedure is done by setting up a pre-determined number of circular, square, or rectangular plots. These plots should be randomly placed and should not over lap. This method is used when all members of the target population can be counted with reasonable certainty(Van Der Avyle & ...