东南太平洋智利竹筴鱼的洄游路线

Migratory route of Chilean jack mackerel Trachurus murphyi in Southeast Pacific

为开展东南太平洋智利竹筴鱼Trachurus murphyi洄游路线的研究,根据中国2000—2003、2007—2009、2016年东南太平洋智利竹筴鱼大型拖网渔捞日志及生物学数据,结合海表温度(sea surface temperature,SST)、海表面盐度(sea surface salinity,SSS)、叶绿素a浓度(chlorophyll a,Chl-a)等数据,采用神经网络模型和频率分布法对智利竹筴鱼洄游路线进行了分析验证。结果表明:以2~4龄为优势叉长的智利竹筴鱼鱼群自智利和秘鲁沿岸海域向西洄游,于5月到达39.5°S、78°W附近海区后,向西北方向索饵洄游和越冬洄游,10月鱼群到达33°S、85°W附近海域后,折向西南方向进行产卵前的索饵洄游,11月—翌年3月鱼群到达产卵场37°~39°S、85°~88°W海区;翌年3—4月自产卵场向西南方向进行索饵洄游,翌年5月到达41°S、87°W附近海区后,折向西北方向索饵洄游和越冬洄游,翌年10月鱼群到达36.5°S、95°W附近海区后,折向西南方向进行产卵前的索饵洄游。研究表明:智利竹筴鱼鱼群5—10月向西北方向洄游,10月—翌年4月向西南方向洄游;同一经度上较大个体竹筴鱼偏向南,同一纬度上较大个体竹筴鱼偏向西南,呈S形向西进行洄游。

The migration route of Chilean jack mackerel Trachurus murphyi in Southeast Pacific was investigated by frequency distribution method and neural network based on the fishing data and biological data of Chilean jack mackerel obtained by Chinese large trawling fleets in the Southeast Pacific from 2000 to 2003,from 2007 to 2009,and 2016 and combining with the data of sea surface temperature(SST),sea surface salinity(SSS),chlorophyll a concentration(Chl-a).The results showed that the school with dominant fork length of 2-4 years old fish migrated westward from the coastal waters of Chile and Peru to reach the sea area near 39.5°S and 78°W in May,and that the fish school migrated to the northwest for feeding and overwintering.After reaching the sea area near 33°S and 85°W in October,the fish school turned to the southwest for feeding before spawning.From November to next March,they reached the spawning ground-the sea areas near 37°-39°S and 85°-88°W.From next March to April,the fish school moved from the spawning ground to the southwest.After reaching the sea area near 41°S and 87°W in next May,the fish school turned to the northwest for feeding and overwintering.After reaching the sea area near 36.5°S and 95°W in next October,the fish school turned to the southwest for feeding before spawning.The findings indicated that the fish school migrated to the northwest from May to October,and then turned to the southwest from October to April of the next year.Large Chilean jack mackerel at the same longitude tended to migrate to the south,while large Chilean jack mackerel at the same latitude tended to migrate to the west with an S shape westward migration.