Acta Ichthyologica et Piscatoria 21(2): 75-85, doi: 10.3750/AIP1991.21.2.09
An attempt to estimate changes in the fish stock of Lake Jeziorak on the basis of the fishing yield of seines
expand article infoA. Bonar
Open Access
Analyses were performed of changes in the fishing yield and fish composition of catches obtained with seine nets in Lake Jeziorak in 1967-1985. The results were compared with similar data for 33 lakes of pikeperch type. It was found that average fishing yield of seines in Lake Jeziorak amounted to 362.87 kg, being 115.98 kg higher than the average calculated for 33 lakes of pikeperch type. Fishing yield showed an increasing trend at decreasing fishing effort and increasing fish catches. These differences and trends were caused by: change of the protective size for bream, so that specimens smaller than 0.5 kg were caught, and increased predation which reduced prey fish stocks, mainly that of roach.