菲律宾海夏季仔稚鱼表层分布及其与环境因子的关系OA北大核心CSTPCD

In order to investigate the relationship between the surface distribution of fish larvae and juveniles and environmental factors in the Philippine Sea in summer,surface horizontal trawl surveys were conducted with large larvae and juvenile fish nets(diameter 1.3 m,mesh 0.5 mm)at 50 sampling stations in the Philippine Sea(11°N-19°N,129°E-138°E)during the summer of 2022.A total of 38 159 fish larvae and juveniles,belonging to 14 orders,21 families,and 56 species were collected.The dominant species in the daytime collection were Thunnus albacares and Encrasicholina punctifer,while the dominant species in the nighttime collection was Encrasicholina punctifer,so the co-dominant species was Encrasicholina punctifer,which accounted for 97.05％of the total number of samples collected.The total mean density of fish larvae and juveniles at each station was 292.43 ind./1 000 m3,with a mean density of 17.61 ind./1 000 m3 collected during the daytime and 526.54 ind./1 000 m3 collected during the nighttime,indicating significant differences in diel distribution.The stations with higher densities were mainly located in the sea near 15° N,and all sample were collected at night.Canonical correlation analysis showed that the environmental factors affecting the distribution of fish larvae and juveniles were,in descending order,sea surface salinity,sea surface temperature,and dissolved oxygen.The distribution of the dominant species Encrasicholina punctifer was mainly influenced by sea surface salinity and dissolved oxygen.The study shows that the fish larvae and juveniles in the Philippine Sea have a rich species composition with uneven surface distribution and significant differences in diel distribution.This study can provide a scientific basis for the assessment,conservation and utilization of fishery resources in the Philippine Sea.