| Popis: |
The Biological Reference Points are values of the level of fishing mortality or of the biomass of the stock which seek a long-term sustainable exploitation of the stocks, with the best possible catch. Von Bertalanffy's growth parameters: L∞ = 39.64 (cm), K = 0.36 (year-1), t0 = -0.22 (year), W∞ = 454.85 (g), and the monthly monitoring of size frequencies, allowed to identify the size of first sexual maturity L50, total mortality (Z = 2.11), natural mortality (M = 0.57) and fishing mortality (F = 1.54), all these values were evaluated in the objective to estimate the biological reference points. The assessment was performed using length cohort analysis (LCA) and biomass and yield per recruit’s analyses as implemented in VIT4Win software, the program reconstructs the population using mortality vectors and the production per recruit analysis is based on fishing mortality (F). The values of mortality determined seem concentrated on individuals with a size between 22 and 26 cm Lt, Maximum Sustainable Yield MSY 43.25g,the total balanced biomass was estimated at 3.84 t and the yield per recruit analysis (Y/R = 27.87 g) based on current fishing effort showed that the stock is at its minimum operating limit. |
