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以2009年至2010年在东海中部采集的鲐鱼(Scomber japonicus)样本叉长数据为基础,结合历史数据,开展叉长数据误差对资源评估结果影响的研究。评估考虑2种情况:1)使用完整采样数据和历史数据建立Von Bertalanffy生长方程,并将鲐鱼的叉长转换为年龄。其生长参数为:K=0.49,L∞=404.6,t0=-0.9;2)删除部分大个体鲐鱼,使用剩余叉长数据建立有误差的Von Bertalanffy生长方程,同样将叉长转换为年龄。其生长参数为:K=0.4,L∞=372.5,t0=-0.34。根据以上2个转换结果,基于2006年至2012年鲐鱼产量和捕捞努力量等数据,分别进行资源评估。2组数据得出的剩余产量曲线基本吻合,最大可持续产量(MSY)和捕捞努力量(EMSY)分别约为18.8万t和72艘标准机轮围网渔船。而亲体补充量曲线则相去甚远,含有误差的年龄分组得出的亲体量范围在3000×106到5000×106之间,呈现出亲体量过高,需要增加捕捞努力量来提高补充量的状态,这与现实情况的400×106到500×106不相符。含误差的分组预测出的近几十年亲体量和渔获量是大幅度周期性剧烈变化的,生物量将在1年内达到高峰值约135.5万t,而随后2年内降至约40万t,之后又将在2年内升至高峰值,以此周期循环。亲体量的高峰值与低谷值与渔获量十分接近,渔获量的高峰值与低谷值维持在约60万t和15万t左右。与无误差分组得出的生物量将在6年内减少至约32.3万t,随后保持稳定,亲体量与年渔获量分别将稳定在15.8万t和10.5万t的评估结果相比存在很大差异。
Based on the fork length data of Scomber japonicus collected in the central part of East China Sea from 2009 to 2010, combined with historical data, the impact of fork length data error on resource assessment results was studied. The assessment considers two scenarios: 1) The Von Bertalanffy growth equation is established using the complete sample data and historical data, and the length of the bonito is converted to age. The growth parameters are as follows: K = 0.49, L∞ = 404.6, t0 = -0.9; 2) Some large-body mandarin fish are deleted and the error Von Bertalanffy growth equation is established by using the remaining fork length data. The growth parameters are: K = 0.4, L∞ = 372.5, t0 = -0.34. Based on the above two conversions, resource estimates are based on data such as catfish production and fishing effort from 2006 to 2012. The remaining production curves obtained by the two sets of data are basically in line with the maximum sustainable yield (MSY) and fishing effort (EMSY) of about 188,000 t and 72 standard seine seiners respectively. However, the curves of parental replenishment volume are very far apart. The error rate of parental population ranged from 3000 × 106 to 5000 × 106, showing the status that the parental body mass is too high and the effort of fishing needs to be increased to increase the replenishment volume , Which is not consistent with the actual situation of 400 × 106 to 500 × 106. Predicted parental and catches over the past few decades have been drastically cyclically drastic, as predicted by the error-prone subgroups, with biomass reaching a peak of about 1.355 million t in a year and falling to about 400 000 t in the next two years , And then rise again in two years to a peak, in order to cycle. The peaks and troughs of parental quantities are very close to those of catches, and the peak and trough values of catches are maintained at around 600,000 t and 150,000 t. The biomass with error-free grouping will be reduced to about 323,000 t within 6 years and then remain stable. The amount of parental and annual catches will be stable at 15.8 and 105,000 t respectively difference.