黄海秋季鱼类群落关键种的年代际变化

Interdecadal Changes in Keystone Species of Fish Community during Autumn in the Yellow Sea

本研究基于1985、2001、2009和2018年秋季黄海渔业资源调查数据,构建了黄海鱼类群落食物网拓扑结构,分析了黄海鱼类群落关键种的年代际变化。结果显示,1985-2018年间,黄海鱼类食物网包含物种67~103个,摄食关系数量为300~449个,食物网拓扑结构密度范围为0.198~0.227,种间关联度为0.044~0.074,符合自然条件下的群落种间摄食关系。1985-2018年间,黄海秋季鱼类群落关键种为鳀(Engraulis japonicus)、黄[鱼安][鱼康](Lophius litulon)和小黄鱼(Larimichthys polyactis)。秋季黄海关键种并未发生变化,鳀为关键被捕食者,小黄鱼是控制群落离散变量的物种,两者的资源均出现衰退;黄[鱼安][鱼康]作为关键捕食者,其相对资源量上升。1985-2018年间,秋季黄海优势种变化明显,由黄[鱼安][鱼康]和银鲳(Pampus argenteus)转变为龙头鱼(Harpadon nehereus)、细纹狮子鱼(Liparis tanakae)和鳀;以重量和数量计算的丰富度指数(Rw和Rn)、多样性指数(Hw’和Rn’)逐步降低,2018年以后显著回升,均匀度指数(Jw’和Jn’)波动较小。研究表明,近30年秋季黄海关键种没有变化,但优势种变化明显,群落结构有波动,但仍处于较稳定状态。

Keystone species play an important role in structural stability of a community and changes in diversity.Using Yellow Sea autumn survey data for 1985,2001,2009,and 2018,we constructed the topological structure of the food-web network of the Yellow Sea fish community and analyzed the interdecadal changes of keystone species in the Yellow Sea fish community.The food webs included 67~103 different fish species and 300~449 prey-predator relationships.The structural density of these food webs ranged from 0.198 to 0.227,and interspecies connectivity ranged between 0.044 and 0.074,consistent with fish communities under natural conditions.The keystone species of the autumn fish community in the Yellow Sea from 1985 to 2018 were Engraulis japonicus,Lophius litulon,and Larimichthys polyactis,remaining unchanged for nearly 30 years.E.japonicus is the keystone prey in the fish community,while L.polyactis as a species that controls the fragmentation of community,both resources decline.As the keystone predator,L.litulon resources have gradually increased.From 1985 to 2018,the dominant species in the Yellow Sea changed significantly in autumn,gradually shifting from L.polyactis and Pampus argenteus to Harpadon nehereus,Liparis tanakae,and E.japonicus.The Margalef richness index(Rw,Rn)and Shannon diversity index(H'w,H'n)calculated by weight and quantity have gradually decreased and have rebounded significantly in 2018,while Pielou evenness index(J'w,J'n)fluctuated slightly.The keystone species in the Yellow Sea did not change in autumn;however,the dominant species changed significantly,while the community structure fluctuated slightly but still remained in a relatively stable state.