黄海玉筋鱼生物学特性的年际变化

鱼类的生长和死亡参数是实行渔业资源评估和管理的基础。根据2002—2018年在黄海采集的玉筋鱼（）样品,本研究估测了玉筋鱼在3个渔业利用时期（2000年代初、2000年代末和2010年代末,在此分别称为早期、中期、近期）的生长和死亡参数。结果显示玉筋鱼生物学特性发生了显著的变化,优势体长组由早期的130~150 mm减小到近期的80~110 mm;优势体重组由早、中期较为均匀的分布变为近期的以小个体为主;优势年龄组从早期的2龄个体变为近期的当年生个体。玉筋鱼3个时期的von Bertalanffy生长方程的极限体长（分别为0.31、0.42、0.47。残差平方和分析显示中期与近期的生长方程之间差异显著（<0.05）,与早期和中期相比,近期极限体长下降,生长速率上升。玉筋鱼近期春季、夏季和冬季的肥满度与早期相比均出现了下降。3个时期总死亡率（）分别为0.35、0.44和0.50。玉筋鱼自大规模开发至今经历了过度开发并且趋向于低龄化、小型化,这一变化可能是过度捕捞导致的。

Interannual variation in biological characteristics of sand lance (Ammodytes personatus) in the Yellow Sea

Growth and mortality parameters of fishes constitute the basis of fishery assessments and management. In this study, growth parameters from three time periods ("early", "middle", and "recent") were studied based on sand lance samples collected from 2002 to 2018 in the Yellow Sea. Early period refers to early 2000s, middle period refers to late 2000s, and recent period refers to late 2010s. The results showed that the biological characteristics of sand lance had changed significantly throughout this period. The dominant body length decreased from 130−150 mm in the early period to 80−110 mm in the recent period. Body weight composition changed from a uniform distribution in the early and middle periods to those of small individuals in the recent period. The dominant age group changed from 2-year-old individuals in the early period to individuals born in the current year in the recent period. The of von Bertalanffy growth equations for the early period, middle period, and recent period were 194.2 mm, 179.6 mm, and 161.7 mm, respectively, and the growth rates were 0.31, 0.42, and 0.47 in the early, middle, and recent periods, respectively. Significant differences were observed in the von Bertalanffy growth models (<0.05) between the middle period and recent period. Compared with the previous two periods, the of the recent period was significantly decreased, and the growth rate increased rapidly. The condition factors of sand lance in the spring, summer, and winter of the recent period were decreased compared to the same seasons in the early period. The total mortality rates () of the three periods were 1.14, 2.00, and 0.74, respectively, the fishing development rates () of the three periods were 0.69, 0.78, and 0.32, respectively, and the natural mortality rates () of the three periods were 0.35, 0.44, and 0.50, respectively. Sand lance have been over-exploited since its large-scale development and fish tended to be smaller and younger in recent sampling efforts. Such changes may be caused by overfishing.