阿根廷滑柔鱼(Illex angentinus)为大洋性浅海种,为世界重要经济种类,其中马尔维纳斯群岛海域是阿根廷滑柔鱼的重要渔场之一。阿根廷滑柔鱼资源丰度极易受到海洋环境变化的影响,年间产量波动较为明显。为此,根据1995—2019年马尔维纳斯群岛阿根廷滑柔鱼渔业生产数据,以单位捕捞努力量渔获量(catch per unit effort, CPUE)表征阿根廷滑柔鱼资源丰度,运用灰色GM(1,1)模型,对其未来的资源丰度丰歉年份进行预测。结果表明,阿根廷滑柔鱼资源丰度丰年(CPUE大于1615t/船)将发生在2021、2028和2038年,资源丰度歉年(CPUE小于784t/船)将发生在2024、2029和2036年;丰年灾变模型的平均相对误差为16.212%,平均级比偏差为0.193,歉年灾变模型的平均相对误差为35.656%,平均级比偏差为0.199,模型的精度检验等级均为Ⅰ级。研究认为,灰色灾变预测模型较好地模拟了阿根廷滑柔鱼资源丰度变化的年份,其预测结果可为阿根廷滑柔鱼鱿钓生产与管理提供参考。
Based on the biological data of bigeye tuna measured from the longlining ground of the Central Atlantic Ocean from Jun.2001 to Oct.2001,this paper analyzed the bigeye tuna’s maturity stages of the gonad,feeding intensity,species composition of prey,sex ratio,fork length distribution,relationships between fork length and dressed weight,fork length and round weight,round weight and dressed weight by statistic and regression methods.The results indicate: (1)Maturity at Ⅳ-Ⅵ of the gonad are dominant with the highest percentage of Ⅴ(30.11%).(2)The feeding intensity is mainly in the class 1,class 2 or class 3,totally 83.16%.(3)In the bigeye tuna’s species composition of prey,the percentage of miscellaneous fish or cephalopod is relatively high,38.05% or 30.48% respectively.Catch rate of bigeye tuna can be enhanced when cephalopod is used as the bait.(4)The male-female ratio is 2∶1.This pattern might result from elevated mortality of adult females.(5)The fork length distribution is suitable for the normal. The dominant fork length is 1.13-1.49m, 64.16%, with the mean value of 1.32m. (6)The relationship between fork length and dressed weight.(7)The relationship between fork length and round weight.If the fork length is the same,the round weight converted in this paper’s formula is a little lighter than the round weight converted in Parks’s formula concluded at 1981 of the longline bigeye tuna catch.It might be caused by the different sampling areas or sampling time.(8)The relationship between round weight and dressed weight.The round weight conversion factor in this paper is a little higher than the ICCAT.It might be caused by the different processing methods.ICCAT is recommended to adapt this paper’s conversion factor.
