Evaluating Age Determination for Opercula of European Perch (Perca fluviatilis)

Age determination is a crucial aspect of fishery management, as it provides valuable information on growth rates and age structure. Age data can traditionally be obtained by observing age groups in length-frequency histograms over time, but this time- and cost-effective approach has its limitations. As fish age and their growth rates slow, the age groups start to overlap, requiring computational methods to accurately separate these groups and achieve a clearer analysis of size-frequency data (Macdonald and Pitcher 1979).