Abstract
The aim of study was to assess the effect of fishing season on value in use, intrinsic properties, chemical composition, and the fatty acid profile of the muscle tissue of free-living perch Perca fluviatilis L. caught in the Bystrzyca River. The research material comprised forty specimens of both sexes aged over 4 years. The fish were caught during two seasons in 2011, i.e. 20 specimens in spring (March/April), and 20 specimens in fall (October/November). No significant differences in the weight, length and condition, or in the value in use of the fish from the spring and fall seasons were noted. Fishing season had no significant effect on pH or the electrical conductivity value of perch muscle tissue. However, the color of the muscle tissue of fish from the spring season was redder and more intense. Significantly higher levels of fat and ash were noted in the muscle tissue of perch from the fall season, and this contributed to its higher nutritional value in comparison to fish caught in the spring. Furthermore, the muscle tissue of fish caught in the fall season was of greater preventive health value for consumers because of the significantly lower share of saturated fatty acids and higher concentration of long-chain n-3 polyunsaturated fatty acids, especially eicosapentaenoic, docosapentaenoic and docosahexaenoic.