Various aspects of the distribution and biology of turbot in the Black Sea

Abstract

The present study aims to address various aspects of the biology and distribution of turbot based on isometric data from landings at authorized ports during the period 2017-2022. By synthesizing and analyzing data from turbot fishing, we gain insights into the species' history, distribution, and life cycle, which is crucial for science and beneficial for fisheries management. The study focuses on: distribution, length-weight relationship, and condition factor of turbot. Data were collected from authorized Bulgarian ports in the Black Sea during 2017- 2022. Samples were taken from 4719 fish. The average total length and weight of the fish were 52.63±6.12 cm and 2600±910 g, respectively. The length-weight relationships were determined using the following equations: 2017: W = 0.02L2.98, n = 566 (R2 = 0.88); 2018: W = 0.04L2.80, n = 783 (R2 = 0.85); 2019: W = 0.34L2.25, n = 713 (R2 = 0.71); 2020: W = 0.02L2.90, n = 926, (R2 = 0.89); 2021: W = 0.02L2.93, n = 928, (R2 =0.88); 2022: W = 0.002L3.55, n = 803, (R2 =0.86); 2017-2022: W = 0.05L2.76, n= 4 719, (R2 =0.74). The reproductive period of turbot in the Black Sea is between April and June. The condition factor during the period 2017-2022 varied as follows: 1.74, 1.86, 1.75, 1.74, 1.74, 1.91. The overall average value of the Fulton’s condition factor during the study years was above one, indicating the good status of the turbot population (Psetta maxima) in the Bulgarian waters of the Black Sea.