东南太平洋智利竹筴鱼渔场浮游生物数量分布及与渔场关系

2006年6~8月,对智利外海渔场的5个站点(31°00′~40°45′S、82°05′~91°52′W)进行了浮游生物调查。结果显示,浮游植物共有7属10种,其中硅藻门有5属5种,甲藻门1属3种,蓝藻门1属2种;浮游植物平均生物量为0.416 mg/m3,最高生物量为0.822 mg/m3,最低为0.13 mg/m3。浮游动物为33属40种,其中桡足类有14种,占总种类数的35%,其次为浮游幼虫、水螅水母类、糠虾类和磷虾类等;浮游动物平均生物量为0.656 mg/m3,最高丰度为211 ind/m3,最低为33.5 ind/m3。通过对智利竹筴鱼产量及CPUE(单位渔获量努力量)叠加分析,发现中心渔场区域主要集中于38~43°S、80~83°W范围内,与各采样站点浮游植物生物量分布趋势一致,中心渔场与表层浮游动物生物量的分布尚不存在相对应的关联。

Distribution of plankton on Trachurus murphyi fishing grounds of the Southeast Pacific and its relationship with fishing grounds

The plankton survey was carried out from the five selected station points within the area,31°00′-40°45′S,82°05′-91°52′W during June-August 2006.The results showed that there existed 7 genera and 11 species of phytoplankton in the monitoring waters.The Bacillariophyta included 5 genera and 5 species,the Pyrrophyta 1 genera and 3 species and the Cyanophyta 1 genera and 3 species.The average biomass of phytoplankton was 0.416 mg/m3 with the highest 0.822 mg/m3 and the lowest 0.13 mg/m3.As for zooplankton,there were 33 genera and 40 species,of which the predominant Copepoda included 14 species,and accounted for about 35% of the total number of species.Pelagic larvae,Hydromedusa,Mysidae and Euphausiidae come second with the average biomass of zooplankton 0.656 mg/m3,the highest 211 ind/m3 and the lowest 33.5 ind/m3.By the integrated analysis on CPUE and production of Trachurus murphyi,we found the main center fishing ground was on 38-43°S,80-83°W.The CPUE and production trend was similar with the distribution of phytoplankton while the distribution of zooplankton was not well correlated with the trend.