海州湾及邻近海域春夏季典型断面鱼类浮游生物群落的结构特征

根据2015年5―7月在海州湾及邻近海域存在空间异质性的南北两个典型断面进行的鱼卵、仔稚鱼水平拖网调查数据,采用多元统计分析等方法研究了该海域春、夏季鱼类浮游生物群落的空间变化。结果表明,本次调查共获得鱼卵33587粒,仔稚鱼713尾。出现鱼卵25种(未定种1种),隶属于14科25属,仔稚鱼13种(未定种1种),隶属于13科13属。鱼卵优势种主要是鳀(Engraulis japonicus)、多鳞鱚(Sillago sihama)、(魚銜)属(Callionymus spp.)、皮氏叫姑鱼(Johnius belengerii)、江口小公鱼(Stolephorus commersonni)和短吻红舌鳎(Cynoglossus joyneri);仔稚鱼优势种主要是(魚銜)属和斑鰶(Konosirus punctatus)。鱼类浮游生物种类组成年代际变化明显,目前以生命周期短、个体小、资源更新节律快的小型鱼种为主;研究表明,鱼类浮游生物的优势种在不同月份和断面之间存在一定变化,5、6月南北两断面优势种组成不同,7月开始出现共同优势种。从鱼类浮游生物的空间分布来看,近岸海域的丰度较高,5、6月鱼类浮游生物的平均丰度均为北面断面1高于南面断面2,7月反之。鱼类浮游生物群落在两个典型断面随月份呈现出不同特征,水深、温度和盐等海洋环境因子综合影响着春、夏季海州湾及邻近海域鱼类浮游生物群落结构。

Community structure of ichthyoplankton from typical transects in Haizhou Bay and its adjacent waters during spring and summer

The area of Haizhou Bay and its adjacent waters is an important spawning and feeding ground for many economically important fish and invertebrate species.It is also one of the important fishing grounds in the coastal waters of China.Environmental factors including sediment types,water depth,and hydrodynamics are heterogeneous in Haizhou Bay and its adjacent waters;this could affect the ichthyoplankton community structure during the main spawning period of spring and summer for many fish species.The species composition,dominant species,egg and larval abundance,and spatial structure of the ichthyoplankton community were analyzed using the index of relative importance and multivariate statistical analysis of data collected from fish eggs and larval surveys conducted by horizontal tows using plankton net,from May to July in 2015 in Haizhou Bay and its adjacent waters.A total of 33587 fish eggs and 713 larvae were collected during the surveys.Twenty-five species were identified from the eggs belonging to 25 genera and 14 families,while one species was unidentified.The fish eggs were dominated by Engraulis japonicus,Sillago sihama,Callionymus spp.,Johnius belengerii,Stolephorus commersonni,and Cynoglossusjoyneri species.Thirteen species of larvae belonging to 13 genera and 13 families were identified,while one species was unidentified.The dominant species of larvae mainly included Callionymus spp.and Konosirus punctatus.Interannual variability of species composition of ichthyoplankton was observed compared to historical studies,and the main species were small fish species with short life cycles.Cluster analysis was used to divide the community structure based on spatial distribution of species composition and dominant species.The dominant species of ichthyoplankton varied depending on the months and transects.The abundance of fish eggs and larvae in nearshore waters was higher than that in offshore waters.The dominant species composition and abundance of ichthyoplankton varied between transects in May and June and was similar in two transects in July.The vertical profile of temperature and salinity of the two transects in Haizhou Bay and its adjacent waters,was used to analyze the relationship between the distribution of ichthyoplankton community and environmental factors.The spatial structure of ichthyoplankton community in the two transects varied during different months.Water depth,temperature,salinity,and other environmental factors had a comprehensive influence on the spatial variation of the ichthyoplankton community in Haizhou Bay and its adjacent waters from May to July.This study will provide a reference for the protection of the spawning ground,conservation of fishery resources,and management in Haizhou Bay and its adjacent waters.It is necessary to improve the protection of the spawning grounds in Haizhou Bay and its adjacent waters.