山东南部近海秋季长蛇鲻相对资源量的分布及其影响因素

Factors in Southern Coastal Waters of Shandong During Autumn

为探究长蛇鲻(Saurida elongate)的生态习性和分布规律,并为长蛇鲻资源的合理利用与养护提供科学依据,本文根据2016年秋季在山东南部近海进行的渔业资源与环境调查数据,分析了该海域长蛇鲻的分布特征,研究长蛇鲻成体、幼体的分布差异,并利用广义可加模型(GAM)研究其分布与生物因子和环境因子的关系。结果表明,长蛇鲻成体与幼体的分布存在差异,成体分布范围广,幼体主要分布在30 m等深线及以浅水域。GAM模型的结果表明,饵料生物、底层水温、水深和底层盐度是影响长蛇鲻相对资源量分布的主要因子。成体、幼体的分布与影响因子的关系差异极显著(P<0.01)。长蛇鲻成体的相对资源量随饵料生物和底层水温的增加表现为先上升后下降的趋势,而幼体呈现一致上升趋势;成体和幼体的相对资源量随水深增加均呈下降趋势;幼体相对资源量随底层盐度增加有明显上升趋势,而盐度对成体的影响不显著。本研究认为山东南部近海是长蛇鲻的重要栖息地,水温和盐度是成体和幼体分布差异的可能原因。

In order to analyze the ecology and distribution of slender lizardfish(Saurida elongate),and provide scientific basis for sustainable utilization and conservation,the spatial distribution of slender lizardfish was analyzed in coastal waters of southern Shandong,based on the biological and environmental data collected during the fishery independent surveys in October 2016.This study tested whether there were significant differences in the distribution pattern between adult and juvenile slender lizardfish,and used generalized additive model(GAM)to evaluate the relationships between their distribution and biotic and environmental factors.The results indicated different distribution patterns between adults and juveniles,i.e.,adults spread more widely and juvenile were mainly concentrated around the 30m isobath and in shallow waters.GAMs showed that prey,bottom temperature,depth and bottom salinity were influential for the spatial distribution of slender lizardfish,and the influential factors were significant different between adult and juvenile(P<0.01).The relative abundance of adult trended to increase and decrease with prey and bottom temperature,whereas the juvenile trended to increase consistently.Both adult and juvenile were negatively correlated with depth in their distribution.The relative abundance of juvenile tended to increase with salinity,whereas the adult showed insignificant dependence on salinity.This study showed that southern coastal waters of Shandong is an important habitat for slender lizardfish.Temperature and salinity were potential reasons for the distributional difference between adult and juvenile slender lizardfish.