洋山海域大型底栖动物年际生态变化的初步研究

依据2003～2005年洋山海域大型底栖动物的监测结果，运用y、C、d、H’和J等参数，结合聚类分析探讨了该海域大型底栖动物的种类数、生物量、栖息密度和多样性指数的年间变化情况。结果表明，2003～2005年底栖动物出现种类数依次为2003年（21种）〉2004年（17种）〉2005年（16种），种类数趋于减少；生物量呈现2003年（4．26g／m2）〉2005年（2．18g／m2）〉2004年（0．62g／m2），栖息密度2003年（31．10ind／m2）〉2004年（12．50ind／m2）〉2005年（11．00ind／m2），Shannon-Wiener多样性指数（H）、均匀度指数（J）、丰富度指数（d）逐渐降低，单纯度指数（C）相应上升。通过对各次监测结果的聚类分析，将聚类结果分为两类：2003年2、5和8月为一类，2004～2005年6次监测为一类，2003年与2004～2005年的大型底栖动物生态变化明显，洋山深水港工程建设对洋山海域大型底栖动物造成了影响。

Preliminary study on inter annual variations of macrobenthos in Yangshan sea area

According to the results of macrobenthos survey, the inter-annual variation of macrobenthic species composition, biomass, density, community diversity and structure are dis- cussed with parameters including Y, C, d, H＇, J, by using the method of cluster analysis. The result showed that,in 2003,2004 and 2005,the numbers of benthic species were 21,17 and 16, the biomass were 4.26g/m2, 0.62g/m2 and 2.18 g/m2, and the average inhabit densities were 31.10 ind/m2 , 12.50 ind/m2 and 11.00 ind/m2 , respectively. The result indicated that benthic species numbers, biomass, inhabit densities, and diversity indexes were all reducing year by year, while the purity index increased accordingly. Cluster analysis revealed that the results of three surveys in February, May and August, 2003 were in one cluster, while the results of 6 surveys in 2004~2005 were in one cluster. This may indicate that the ecological changes between 2003 and 2004-2005 were obvious, and the ecological changes of macrobenthos were affected by the con- struction of Yangshan deepwater port.