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柔鱼(Ommastrephes bartramii)是短生命周期种类,资源丰度及分布极易受到海洋环境变化的影响。根据2008~2009年7~11月份我国鱿钓船生产数据,结合表温(SST)、叶绿素浓度(Chl-a)、海表面高度(SSH)和盐度(SSS),比较2008与2009年资源丰度年间差异,并利用信息增益技术研究不同环境因子对西北太平洋柔鱼传统作业渔场资源丰度及分布的影响。研究表明,2009年7~11月柔鱼渔获量出现大幅下滑,日产量不足2008年的一半。信息增益结果显示,水温因子是影响其资源丰度变动及分布的最关键因子,叶绿素次之,海表面高度和盐度影响最小。SST与CPUE叠加分析认为,2008年7~11月受SST影响,柔鱼传统作业海域逐渐向东北方向移动,经度最大偏移2°,纬度方向最大偏移为5°左右,较高CPUE所处范围的平均SST逐渐降低,由7月份的16.5℃降至11月份的11℃。2009年7~11月作业渔场随着时间逐渐向东北方向移动,经度最大偏移1°,纬度方向最大偏移为4°左右,平均SST逐渐降低,由7月份的16℃降至11月份的9.5℃。同时2009年作业海域黑潮比2008年平均偏南2.8°,强度减弱,势力范围减小,亲潮冷水团向南入侵势力变强,温度相对2008年平均降低2.5℃,不利于柔鱼洄游。此外,2009年作业渔场大多分布于水温距平均值(SSTA)小于-0.5℃海域以及Chl-a浓度偏高等也导致了柔鱼资源丰度减少产生年间差异。
Ommastrephes bartramii is a short life cycle species whose abundance and distribution of resources are highly susceptible to changes in the marine environment. According to the production data of Chinese squid fishing boat from July to November in 2008 ~ 2009, the SST, the Chl-a, the sea surface height (SSH) and the salinity (SSS) Year differences in abundance, and using information gain techniques to study the impact of different environmental factors on the abundance and distribution of traditional fishing ground resources of Ommastrephes bartrami in the Northwest Pacific. Research shows that during the period from July to November 2009, the catches of Ommastrephes have dropped sharply, with the daily output less than half of that in 2008. The result of information gain shows that water temperature is the most crucial factor that affects the variation and distribution of resource abundance. Chlorophyll is the second, sea surface height and salinity are the least. The superposition analysis of SST and CPUE indicated that the SST influenced the SST from July to November in 2008, while the traditional operating area of Ommastrepus gradually moved to the northeast, the maximum longitude offset was 2 °, and the maximum latitude offset was about 5 °. The higher CPUE The average SST of the range gradually decreased from 16.5 ℃ in July to 11 ℃ in November. From July to November in 2009, the fishing ground gradually moved to the northeast, with the maximum longitude shift of 1 ° and the maximum latitudinal drift of about 4 °. The average SST gradually decreased from 16 ° C in July to November 9.5 ° C. At the same time, in 2009, the Kuroshio Current Operational Area was 2.8 ° southward from 2008, its intensity weakened and its sphere of influence decreased. The intrusion of cold water mass toward the south strengthened its temperature and the temperature dropped 2.5 ° C lower than the average in 2008, which was unfavorable to the migration of squid. In addition, most of the operating fishing grounds in 2009 were located in the sea areas with an average SSTA of less than -0.5 ℃ and the high concentration of Chl-a, which also led to the year-to-year differences in the reduction of squid resource abundance.