舟山沿岸渔场春秋季鱼类群落结构特征分析

Analysis of the Fish Community Structure in the Spring and Autumn of the Zhoushan Coastal Fishing Grounds

根据2015年11月(秋季)、2016年5月(春季)在舟山沿岸渔场开展的渔业资源调查中所获得的鱼类资料,采用群聚的物种相似性、多样性指数、RDA分析等方法,对该海域鱼类种类组成、生态类群、多样性和群聚特征进行了分析。结果显示,本调查共鉴定出鱼类81种,隶属于12目39科63属,以近海暖水种为主;Jaccard相似性指数为37.04%,处于中等不相似水平;优势种计算结果显示,春季优势种为六丝钝尾虾虎鱼(Amblychaeturichthyshexanema),渔获量占总渔获量的42.16%;秋季优势种为龙头鱼(Harpodon nehereus),占总渔获量的43.56%;春季多样性高于秋季,但2个季节的多样性指数平面分布相似,均为调查海域南部最低,越往北多样性指数越高,且东部海域高于西部海域;ANOSIM检验显示,各群落间差异极显著;相似性百分比(SIMPER)显示,蓝圆鲹(Decapterus maruadsi)、棘头梅童鱼(Collichthys lucidus)、龙头鱼等7种,中华小沙丁鱼(Sardinella nymphaea)、鳀(Engraulis japonicus)、七星底灯鱼(Benthosema pterotum)等9种,分别是春、秋季各组群的典型种及造成鱼类群落结构差异的主要分歧种。RDA研究结果显示,盐度、温度是舟山沿岸渔场鱼类群落结构主要的环境影响因子。

Species composition,ecological role,diversity,and clustering characteristics of fish species were analyzed by means of the species similarity,diversity index,and redundancy analysis(RDA)fishery resource surveys data collected in November 2015(autumn)and May 2016(spring)in the Zhoushan coastal fishing ground.The results showed that a total of 81 fish species were identified,which belonged to 63 genera in 39 families of 12 orders,with the bulk belonging to offshore,warm-water species.The Jaccard similarity index is 37.04%at the middle dissimilarity level.Analysis showed that the dominant species in the spring was Amblychaeturichthys hexanema,which accounted for 42.16%of the total catches.The dominant species in the autumn was Harpodon nehereus,which accounted for 43.56%of the total catches.The diversity index value of spring was higher than in autumn.However,the two seasonal diversity indices had similar planar distribution.Diversity was observed to be the lowest in the southern region of the survey area increasing toward the north,and a similar trend was seen from east to west in the survey region.The analysis of similarities(ANOSIM)test showed that the differences between the communities were highly significant.The similarity percentage(SIMPER)showed that seven species of fish,including Decapterus maruadsi,Collichthys lucidus,and H.nehereus,were typical species belonging to different groups in the spring.Fish community structure differed in autumn compared to spring primarily in that there were nine species of fish,including Sardinella nymphaea,Engraulis japonicus,and Benthosema pterotum.The results of the RDA indicated that the main environmental factors influencing the structure of fish community in the Zhoushan coastal fishing grounds were salinity and temperature.