VARIATIONS IN AGE AND LENGTH GROWTH RATES OF VENDACE, COREGONUS ALBULA (L.), FROM SELECTED LAKES IN WESTERN POMERANIA
Przemysław Czerniejewski*, Agnieszka Rybczyk**
*Department of Fisheries Management of Inland Waters, Agricultural University of Szczecin, Poland
**Department of Fish Biology, Agricultural University of Szczecin, Poland
ABSTRACT. The aim of the study was to investigate the age and length growth rate of vendace, Coregonus albula (L.) from several of the most important commercially exploited lakes in Western Pomerania. Age and length growth rates were determined from scales using back-calculations of the Rosa Lee variant as well as mathematical growth models: Ford-Walford, von Bertalanffy, second degree polynomials, and the modified power function. Fish condition was determined based on the Fulton and Clark factors. The analysis of fish age in the individual lakes indicated that vendace from age class 2+ dominated; this was impacted by the deployment of selective gear (gill-nets with 24 mm mesh size). The most advantageous condition measured with the Fulton and Clark factors was noted in the fish from lakes Drawsko and Komorze. The growth of vendace from lakes Drawsko, Siecino, Komorze, and Pile was average, while that of the fish from Lake Kamienny Jaz was slow. Of the four mathematical models of growth rate, the best fit was obtained with the von Bertalanffy variant.
Key words: VENDACE, GROWTH, MATHEMATIC MODELS OF GROWTH, CONDITION
Przemysław Czerniejewski, Akademia Rolnicza, Zakład Gospodarki Rybackiej na Wodach Otwartych, ul. Kazimierza Królewicza 4, 71-550 Szczecin, Tel./Fax: + 48 91 4231061; e-mail: firstname.lastname@example.org