北部湾斑鳍白姑鱼渔业生物学分析

Analysis of fishery biology of Pennahia pawak in Beibu Gulf

通过测量2008—2009和2018—2019年在北部湾海域沿岸北海和东方渔港采集的斑鳍白姑鱼(Pennahia pawak)样品,所得的生物学数据,利用FiSATⅡ软件体长频率分析(ELEFAN)技术,分析斑鳍白姑鱼种群生长、死亡参数和开发率等的变化,以评估2个时段北部湾斑鳍白姑鱼的开发利用状况。结果显示:2008—2009和2018—2019年2个时段北部湾斑鳍白姑鱼优势体长分别为11~17 cm和10~15 cm,平均体长由14.83 cm减小到12.59 cm;优势体质量分别为30~100 g和10~80 g,平均体质量由85.88 g降低至52.91 g;2018—2019年的平均体长、平均体质量分别下降了15.1%和38.4%。2个时段异速生长因子b分别为2.84和3.00,表明斑鳍白姑鱼趋向匀速生长。估算的渐进体长由24.15 cm下降为22.05 cm,下降了8.7%,开捕体长由12.56 cm下降至10.29 cm,下降了18.1%。生长参数K分别为0.39和0.32;总死亡系数分别为1.39和1.17,自然死亡系数分别为0.98和0.90,捕捞死亡系数分别为0.41和0.28;估算的开发率分别为0.29和0.24。综上,北部湾斑鳍白姑鱼趋于小型化,目前该资源呈轻度开发状态。

The samples of Pennahia pawak were collected at the Behai and Dongfang fishing ports along the coast of Beibu Gulf from 2008 to 2009 and 2018 to 2019.Samples were measured for biological data.Length frequency analysis(ELEFAN)technique with FiSATⅡsoftware was used to analyze the growth,mortality parameters and exploitation rate to assess the resource utilization status in the two periods.The results indicated that the dominant body length was 11-17 cm and 10-15 cm,with the body length decreasing from 14.83 cm to 12.59 cm in the two periods.The dominant body mass were 30-100 g and 10-80 g,with the body mass decreasing from 85.88 g to 52.91 g.The average of body length and body mass decreased by 15.1%and 38.4%,respectively.The allometric parameter b in the two periods was 2.84 and 3.00,P.pawak tended to isometric growth.L∞(asymptote length)declined 8.7%from 24.15 cm to 22.05 cm while Lc(first catchable size)declined 18.1%from 12.56 cm to 10.29 cm.The growth parameter K decreased from 0.39 to 0.32.The total mortality coefficient decreased from 1.39 to 1.17.The natural mortality coefficient of P.pawak was 0.98 and 0.90.The fishing mortality coefficients was 0.41 and 0.28.The exploitation rate decreased from 0.29 to 0.24,respectively.The population structure of P.pawak in the Beibu Gulf showed a tendency to miniaturize and it was not over-exploited.