吕泗渔场沿岸海域春夏季虾类群落特征

Shrimp community structure in the Lvsi fishing ground during spring and summer

为研究吕泗渔场沿岸海域虾类群落结构特征,利用2010年春季(5月)和夏季(9月)在吕泗渔场沿岸海域开展渔业资源调查获取的资料,分析了虾类的种类组成、多样性空间分布及群落结构特征,并对其影响因素进行探讨。结果表明:吕泗渔场沿海海域春夏两季共出现虾类18种,其中春季11种,夏季15种;春季优势种为葛氏长臂虾、日本鼓虾和鲜明鼓虾,夏季优势种为哈氏仿对虾和中华管鞭虾。研究表明:吕泗渔场沿岸海域虾类春季以暖温性生态类群为主,夏季以暖水性生态类群为主。吕泗渔场沿岸虾类种类数和多样性指数较高的站位主要集中在调查海域的外侧。运用聚类和多维标度对群落结构的相似性进行分析,结合水深等环境因子对吕泗渔场沿岸海域虾类的群聚类型进行了讨论,吕泗渔场沿岸虾类群落结构季节变化明显、空间差异显著,水团变化、地形、水深是导致吕泗渔场沿岸海域春夏季虾类群落结构时空差异的主要原因。

To understand the seasonal variation in the shrimp communities,temporal changes in species composition and community structure of the shrimp community in the Lvsi fishing ground were examined based on data from bottom trawl surveys during spring and summer of 2010. The result indicated that a total of 18 shrimp species were identified,among which 11 were identified in spring and 15 were identified in summer. In spring,it was mainly composed of warm temperate species. Palaemon gravieri was the dominant species in spring,accounting for 52. 76% and 64. 03% in the individual density and weight density,respectively,while Alpheus juponicus and Alpheus distinguendus were common species. Most of them were warm temperature adapted. In summer,the sea water temperature began to increase,in the meantime,a large quantity of freshwater was found in the area,as a result of the influence of the rainy season and the Yangtse River diluted water. Consequently,shrimp communities showed an obvious succession（ R = 56%）,and warm water species became numerically dominant,for example,Parapenaeopsis hardwickii and Solenocera crassicornis were predominant species in summer,and most of the species belonged to the Indo-West-Pacific warm water region. The warm-temperate species,however,were distinctively decreased during summer. In short,shrimp ecological groups’ change in the Lvsi fishing ground during the spring and summer is related with seasonal and hydrological changes.