梁子湖乌鳢种群动态及最大持续渔获量的研究

STUDIES ON POPULATION DYNAMICS AND AXIMUM SUSTAINABLE YIELD OF CHINESE SNAKE-HEAD FISH,CHANNA ARGUS, IN THE LIANGZI LAKE

  • 摘要: 根据1997年3月-1998年2月在梁子湖取得的672尾乌鳢标本研究了其种群动态及最大持续渔获量。用鳞片鉴定年龄,鳞径与体长的关系为L=2.7683+9.0184S;体长与体重的关系为W=0.0126L(3.0197),体长与体重的von Bertalanffy生长方程为:Lt=81.03×1-e-0.1755(t+0.5690);Wt=7310×1-e-0.1755(t+0.5690)3.0197。种群的年总死亡率为0.5232,自然死亡率为0.3049,捕捞死亡率为0.2182。通过比较各种捕捞强度和最小捕捞规格的不同的总渔获量和群体的相对数量,提出获得持续渔获量的捕捞强度F=0.40和最小捕捞年龄tc=4。

     

    Abstract: The population dynamics and maximum sustainable yield of Chinese snake-head fish, Channa argus, were studied based on 672 specimens taken from Liangzi Lake from March 1997 to February 1998.The scales were used for age determining and to growth back-calculating.The relationship between body length and scale radius can be expressed as L = 2.7683 + 9.0184S, and that between body weight and body length as W = 0.0126L3.0197.von Bertanlanffy growth equation was used for describing the growth of body length in relation to ages as Lt = 81.03 ?l - e-0.1755(t+0.5690) and the growth of body weight as Wt = 7310 ?1 -e-0.1755(t + 0.5690) 3.0197.Dominant age in catches was 3 years old.Total mortality of the population was estimated to be 0.5232, with 0.3049 in natural and 0.2182 in fishing mortality respectively.If the minimum age in catches could be controlled at 4 years old and the fishing mortality at 0.40, a maximum sustainable yield, which is 107% to the present, might be obtained.

     

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