两种典型渔法金枪鱼围网网具的性能差异

摘要：为了量化分析自由鱼群渔法和漂流物渔法的网具性能差异，本文根据2011-2014年金枪鱼围网海上调查数据，采用Bootstrap和GAM方法进行分析。结果显示：（1）漂流物渔法时，网具的最大沉降深度（195.20~219.36m）约为自由鱼群渔法时最大沉降深度 （205.83~219.04m）的94.8%；网具的平均沉降速度（0.152~0.176m/s）约为自由鱼群渔法时平均沉降速度（0.180~0.193m/s）的84.4%~91.2%。（2）捕捞自由鱼群时，影响沉降速度主要因子为10m水层流速（V10），60m水层流速（V60）和跑纲长度（L1）。（3）捕捞漂流物随附群时，影响沉降速度主要因子为60m水层流速（V60），括纲长度（L）和放网速度（V0）。（4）GAM模型结果显示，漂流物渔法时，预测的沉降速度（0.155~0.175m/s）达到海上实测沉降速度的99.4%；自由鱼群渔法时，预测的沉降速度（0.182~0.190m/s）达到海上实测沉降速度的98.4%。本研究结果可为海上作业时，判别海况条件和控制渔法操作提供一定参考。

Differences of gear performance of tuna purse seine between the two kinds of typical fishing method

Abstract: In this paper, according to the survey data of tuna purse seine by sea trials from 2011 to 2014, by using the Bootstrap and generalized additive model (GAM) to quantitatively analysis the differences gear performance of free swimming school and floating objects fishing method. The results show that: (1) the maximum sinking depth of floating objects fishing method (195.20 ~ 219.36 m) is 94.8% of free swimming school fishing method (205.83 ~ 219.04 m); The average sinking speed of the floating objects fishing method (0.152 ~ 0.176 m/s) is 84.4% ~ 91.2% of free swimming school fishing method (0.180 ~ 0.193 m/s). (2) V10, V60 and L1 have a significant impact on the sinking speed for the swimming school fishing method. (3)V60, L and V0 have a significant impact on the sinking speed for the fishing floating objects associated school. (4) The results by GAM prediction show that: the predicted values of sinking speed (0.155 ~ 0.175 m/s) is 99.4% of sea trials for the floating objects fishing method; the predicted values of sinking speed (0.182 ~ 0.190 m/s) is 98.4% of sea trials for the free swimming school fishing method. the results can provide the certain reference on distinguishing the sea condition and controlling the fishing operation for on sea operation.