摘要
20 0 0年 5～ 6月对长江口南岸边滩和崇明岛北面滩涂泥螺 [Bullactaexarata (Philippi,1848) ]种群进行了调查 ,目前长江口地区泥螺种群广泛分布于朝阳农场以南的南汇边滩、杭州湾北岸滩涂、崇明岛 (牛棚港至捕鱼港 )及长兴岛北面滩涂、九段沙中下沙高潮带下缘至低潮带上缘光滩带。分别采用Taylor幂法则、Iwao聚集格局回归分析法及Morisita指数公式计算和统计分析 ,结果表明 :长江口 8个样点间泥螺种群密度差异极显著 ,其种群空间格局理论上属于聚集型负二项分布。其结果主要是由滩涂围垦。
Bullacta exarata (Philippi,1848) is a favorite seafood and a tidal and economic seashell with high nutrition and edible value in South China. It can be found in the intertidal flats in China,Japan and Korean along the coasts of West Pacific Ocean. B.exarata was one important biological resource which played an important role in the food chain of the tidal flat ecosystem as a consumer. Since late 1990s,the population ecology and toxicology of B.exarata had been partly studied along the coasts in Zhejiang,China,however,the spatial distribution had never been analyzed. Moreover, B.exarata had never been reported again up to now in the Yangtze River Estuary although it was first recorded formally in late 1980s. B.exarata population in the Nanhui tidal flat and North Chongming Island in the Yangtze River Estuary had been investigated and analyzed by Taylor' power law,Iwao's patch regression and Morisita index from May to June,2000. The results indicated that the B.exarata population distributed widely between the supratidal zone and subtidal zone of the intertidal flats from south Chaoyang Farm to Luchao Port in Nanhui tidal flat and in North Hangzhou Bay,from Niupenggang Port to Puyu Port in North Chongming Island,in North Changxing Island,Mid and sub Kiuduansha shoal in the Yangtze River Estuary. It was shown that the natural B.exarata population distributed extensively with clumped and negative binomial distribution [Morisita index ( I )=2 61, P <0 01] theoretically. The regression equations of Taylor power law and Iwao's patch regression were ln S 2=-0 7472+1 3484 ln (r 2=0 8132, P <0 01, n =8) and =-1 005+1 0766 (r 2=0 9936, P <0 01, n =8) respectively. The population densities at 8 sample sites in the Yangtze River Estuary (D7>D6>CPB>DZB>CYN>DZN>CNB>CP) were greatly different significantly by the analysis of variance [ANOVA, F =42 52> F 0 01(7,32) =3 26, P <0 01],which were resulted obviously from human activities,including land r
基金
河口海岸国家重点实验室 99年度开放基金资助项目
关键词
泥螺
种群
空间格局
长江河口
夏季
Bullacta exarata
Population
Spatial distribution
Yangtze River Estuary
