人工集鱼装置禁渔期措施对中国大陆金枪鱼围网船队捕捞努力量特征的影响

Impact of fishing aggregation devices(FADs) closure measures on fishing efforts of Chinese tuna purse seine fleets

为探究人工集鱼装置(Fishing Aggregation Devices,FADs)禁渔期措施对中国大陆金枪鱼Thunnus thynnus围网船队捕捞努力量特征的影响,通过收集2012—2015年中国大陆金枪鱼围网船队在中西太平洋的渔捞日志数据,分别对中国船队在禁渔期和非禁渔期的捕捞努力量指标进行比较分析。结果表明:2012和2013年禁渔期和非禁渔期的平均投网时间存在显著性差异(P<0.05),而2014和2015年两者无显著性差异(P>0.05);禁渔期的作业时间利用率始终小于非禁渔期,但在研究期间两者差距逐渐减小;除2015年外,2012—2014年禁渔期的平均投网次数一直小于非禁渔期;禁渔期对自由鱼群的平均投网次数始终大于非禁渔期,且2015年差异最大。研究表明,中国船队可能正在通过主动调整捕捞努力量的投放策略以逐步适应FADs禁渔期措施带来的影响。

The fishing efforts of bigeye tuna Thunnus thynnus were compared between the Fishing Aggregation Devices（ FADs） closure and the non-FADs closure by Chinese tuna purse seine data collected from 2012 to 2015 to evaluate the effects of several conservation and management measures including FADs closure on fishing efforts of bigeye tuna. The results showed that there was significant difference in average searching days between the FADs closure and the non-FADs closure in 2012 and 2013（ P〈0. 05）,without significant difference between the FADs closure and the non-FADs closure in 2014 and 2015（ P〈0. 05）.The utilization of fishing days was always shown to be smaller in the FADs closure than that in the non-FADs closure from 2012-2014,except for 2015,with the gradually diminishing gap between them. There was larger average fishing sets targeting free schools in FADs closure than that in the non-FADs closure,with the maximal difference in 2015. The changes in these features of fishing efforts suggest that Chinese tuna purse seine fleets consider adjusting their fishing efforts strategies actively to adapt to the negative effects that generated from FADs closure measures.