摘要
利用2000～2002年在长江口渔场的底拖网调查资料,运用多样性指数和相似性指数,对该水域的渔业生物群落结构季节变化进行了研究。结果表明:该域的渔业生物群落以鱼类为主要生物类群,占有绝对优势;甲壳类和头足类为其次要组成部分,处于生态劣势。群落生物量以秋季最大,春季最小。渔业生物群落的丰度、多样性以及均匀度以春冬季较高,夏秋季较低,造成这种趋势的原因可能是与带鱼(Trichiurusjaponicus)和小黄鱼(Larimichthyspolyactis)的洄游有关。渔获物组成春冬季之间、夏秋季之间的相似性指数较高。
This study was based on the data by bottom trawl survey in fishing ground of the Yangtze estuary from 2000 to 2002.The results indicated that in this area fish were primary biologic Genus and had absolute predominance. Crustaceans and Cephalopods were the second major composition and had inferior position in fishery biology community of the waterarea. The annual variety of species number of every biologic Genus was that the species number of total fishery biology and fishes and Crustaceans was descending, but the species number of Cephalopods was ascending at first and descending late. The seasonal variety of species number was that the total species number of fishery biology was the least in summer and the most in winter. It was ascending from summer to autumn and to winter, and descending from winter to spring and to summer. Fish species number was the least in summer and the most in autumn and obviously increasing from summer to autumn. It was descending from autumn to winter and spring to summer. The variety of species number of Crustaceans and Cephalopods were the same as the total species number of fishery biology. The variety of dominant species' composition was that the species number was 11 species which represent the former five dominant species in four seasons of each year. In every season, the sum of percentage which the former five dominant species' biomass account for total biomass was above 70%except about 60% in spring and winter of 2001, and the maximum reaching 94.97% in summer of 2001. The economic species, such as Trichiurus japonicus and Larimichthys polyactis, always had absolute predominance in composition of dominant species, but some small pelagic and low quality fishery biology species possessed some definite proportion. The community's biomass is the biggest in autumn and the least in spring. The richness, diversity and evenness of community was comparatively high in spring and winter and low in summer and autumn. The variety of biomass dominance was opposited to the indices of diversity, and the dominant species was not obvious in spring and winter but was obvious in summer and autumn, which maybe resulted from the migration of T. japonicus and L. polyactis. By analysis of the similarity index of fishery biology species composition and the correlation of biomass composition between seasons, the results indicated that the similarity index was comparatively high between spring and winter or between summer and autumn. Spring and winter or summer and autumn were clustering at first. The dominance of victorious species was increasing and the diversity of community was decreasing when the growth rate of competitive species increased, but on the contrary, the dominance was decreasing and the diversity would be increased or maintained at its original state. In summer and autumn, the most economic species was seeking for bait in the fishing ground. At the same time, the bait was more abundance, which leaded to increasing of competitive species' growth rate. The victorious species were obviously T. japonicus and L. polyactis, of which the dominance was increasing, so the diversity of community was more lower. But in winter and spring, the bait biology was not as abundance as the other seasons because of influence from climate terms, and Trichiurus japonicus and Larimichthys polyactis migrated from the fishing ground in the period for living through winter, so the victorious species were some small pelagic and low quality species such as Setipinna taty and Harpadon nehereus. Their dominance was decreasing because the growth rate was decreasing, so the diversity of community was more higher in these seasons than in the other seasons.
出处
《中国水产科学》
CAS
CSCD
北大核心
2004年第5期432-439,共8页
Journal of Fishery Sciences of China
基金
国家重点基础研究发展规划项目(G19990437)
中国水产科学研究院基金项目
关键词
长江口
渔业生物
优势种
多样性
Yangtze estuary
fishery biology
dominant species
diversity
