黄海口及邻近海域鱼类群落时空格局与优势种特征研究

黄河季节性入海径流所携入的淡水、泥沙及营养物质，与渤海海洋环境相互作用，因而形成了黄河口及邻近水域多种经济种类的产卵场和育幼场。然而，近代黄河尾闾不断变化，加上近年来黄河水资源过度利用和上游生态环境恶化所引起的断水断流，导致了冲淡水和营养盐来源短缺。研究表明，黄河口及邻近海域的生态环境质量，将直接影响到渤海，乃至黄海生物资源动态及其可持续性(乐肯堂，1995;乐肯堂等，1995;沈志良等，1989; Yang et al.，1993)。在过去的20年内，许多研究人员曾进行过多次渤海水域生态环境和渔业资源综合调查。朱鑫华(1996，1998)曾就20世纪80-90年代进行的两次调查资料对渤海鱼类群落的时空格局进行了因子分析，指出渤海3湾的鱼类群落演替呈现较不稳定性格局。本文结合以上调查及其相关研究项目，以1982-1985年的周年调查资料为本底资料，重点研究黄河口及邻近水域鱼类群落生态密度结构特征；结合20世纪90年代现场比较调查资料，分析生物资源对黄河水、沙等生态环境变化的响应特征。

SPATIOTEMPORAL PATTERN AND DOMINANT COMPONENT OF FISH COMMUNITY IN THE YELLOW RIVER ESTURY AND ITS ADJACENT WATERS

Runoff from the Yellow River, the second largest in China, has historically nourished the fisheries resources in Laizhou Bay waters for a long time. However, a recent reduction in seasonal or annual outflow could lead to decline in nutrient flux and biological productivity. Our data from a series of comprehensive surveys in the above waters since 1982, showed that the 114 species of fish in the community were dominated by 66 warm-temperate species comprising 52.28% of total NED (Ecological Density of Number) and 57.06% of total BED (Ecological Density of Biomass). These fish averaging 14.48g, were much smaller than cold-temperate species. Therefore, the seasonal alteration in ecological density within the community could be differentiated into a November to next July cold group, characterized by abundant recruitment in estuarine waters, and an August to October warm group, characterized by congregation of maturing species for spawning. It was found that the spatial dynamics of e fish community in the studied area differed little among stations, and that numerical parameters were directly proportional to water depth. Although there were large seasonal variations in both species composition and ecological density in the fish community, japanese anchovy, Engraulis japonicus T. et. S, and hair-fin anchovy, Setipinna taty (V.) maintained and controlled the overall development of the nekton community in the waters.