Growth and Abundance of Burbot in the Curonian Lagoon and Determinatives of Burbot Abundance

Abstract

Growth and nutrition peculiarities as well as puberty age of burbot juveniles were investigated in the lower Nemunas. According to the investigation data, the mean length and weight of burbot juveniles range from 20.1 cm and 44.6 g of 1+ year-old individuals, to 26.1 cm and 106.1 g of 2+ yearold individuals and to 38.9 cm and 277.4 g of the 3+ year-old fish respectively. Burbot males can reach maturity at the age of 2+ with their body length measuring 20 cm, whereas females maturate at the age of 3+ with the body length of 36 cm. The analysis of commercial burbot catches in the Kaliningrad Region and in Lithuania over the last 50 years was carried out with the reasons of fluctuations in catches specified. It was established that the main reason of decrease in burbot resources and catches is the impact of climate warming on their reproduction. The sequence of four–six cold winters may be followed by a 3–5-fold increase in burbot catches which lately has been prevented by winter floods and thaws and the res...