广东沿岸海域鱼类群落排序

根据广东沿岸海域春秋两季底拖网鱼类采样数据，运用多维尺度转换分别对两季的鱼类样品进行排序。排序揭示出的鱼类群落格局及其季度差异与环境变异性密切相关。同处混合水区域的站位鱼类组成较为相似；分布在珠江冲淡水和外海高盐水区域的站位，鱼类组成则与多数沿岸站位有明显差异。春季沿岸海域鱼类组成有一东北－西南向的变化趋势，这一群落格局是由于该海域东北部受低温东海沿岸流影响所致；秋季珠江河口区受冲淡水的影响，而调

^ORDINATIONS OF FISH COMMUNITIES IN THE INSHORE WATERS OF GUANGDONG PROVINCE

Demersal trawl sampling, representing 2 hydrographic seasons,were carried out in spring and autumn at stations distributed in the inshore waters of Guangdong Province.Ordinations of fish samples were derived,separately for the 2 hydrographic seasons, from multidimensional scsling of percentage dissimilarity matrices. The community patterns and their seasonal differences revealed by the ordinations are well correlated with the distributions and variations of the coastal and off shore water systems.In both seasons,fish assemblage.s are similar at most stations distributed in zones of mixed waters.The assemblages at other station groups differ distinctly from those of the most stations, respectively characterizing the Pearl River diluted water and the offshore saline water mass.The ordination of spring samples revealed a northeast-southwest difference of fish assemblages at most stations.This difference is caused by the invasion of the low temperature East China Sea coastal current in the northeastern part of the investigation area. Fish assemblages of autumn samples change along a salinity gradient from estuary, coastal,to offshore areas.The autumn community pattern is induced by the widespread of diluted water in the Pearl River estuary,and the invasion of off shore saline Water mass into the bottom layer of the outer edge of the investigation area. The community patterns in the Pearl River mouth are subjected to distributions and seasonal variations of river discharge, and changes of fish assemblages along salinity gradients are evident in both seasons.