Jerzy Janusz  and  Kordian Trella
Sea Fisheries Institute, Kołłątaja 1, 81-332 Gdynia, Poland

Key words: walleye pollock, Theragra chalcogramma, Bering Sea, Russian shelf, fish biology.

Abstract.
This work presents the results of investigations from 1995 to1998 which were focused on the walleye pollock stock in the Cape Navarin area (Bering Sea). The length, age, weight and sexual maturity of the fish of the exploited stock were determined. The length and age frequencies of walleye pollock varied throughout the investigations. The average walleye pollock lengths from 1996 to1998 were almost the same, 40.4 cm, as was the average age, 5.3 years. Only in 1995 was the average length shorter, 39.0 cm, and the average age lower, 4.6 years. The parameters of the von Bertalanffy growth equation were determined using average lengths in age groups from four years and the relationship between fish weight and length were determited. The results of the investigations indicate a high degree of similarity between the biological features of walleye pollock in the Cape Navarin area in comparison with results of investigations in the northeastern Bering Sea shelf.