Influence of Composition and Quantity of the Fish Age Structure Data in Catches to Determining the Relative Abundance of Generation under Incomplete Initial Information Conditions

The influence of the age structure data amount and composition on the error estimating the relative abundance of fish generation by the biostatistical method (loss from fishing) under incomplete initial information is analyzed. Using the example of the analysis of test net catches (fixed nets with mesh 35–90 mm, 31525 fish specimens) of bream (L.) from the Kulbyshev Reservoir (2000–2018), it is shown that to estimate the relative abundance of a generation with a given average error of 10–15%, data on its share in catches for 3–4 years (not necessarily adjacent) are sufficient. With such information available for 5–6 years, the average error in the estimate was