内陆排污对杭州湾南岸滩涂湿地浮游桡足类群落结构的影响

2010年1月～2011年1月,在杭州湾南岸滩涂湿地5个断面(S1～S3为排水区,S4～S5为非排水区。)10个采样站进行桡足类群落结构的周年调查,分析了不同生态环境下桡足类群落的种类组成、密度、生物量和种类丰富度等时空变化特征。共发现桡足类19种,剑水蚤和猛水蚤各7种、哲水蚤5种,其中,8种为淡水种,11种为咸淡水种。根据种群的年平均密度和出现频度,淡水种类的优势种为汤匙华哲水蚤(Sinocalanus dorrii)、台湾温剑水蚤(Thermocyclops taihokuensis)和三角大吉猛水蚤(Tachidius triangularis),半咸淡水种类的优势种为中华哲水蚤(Calanus sinicus)和球状许水蚤(Schmackeria forbesi)。群落年平均密度变幅2.64～39.16/L,平均13.54/L;生物量0～2.078 mg/L,平均0.164 mg/L。哲水蚤的群落密度和生物量分别占总桡足类的29.32%和79.88%。密度季节变化以春季>秋季>夏季>冬季,水平变化以S3>S2>S1>S5>S4,S2断面中潮位比高潮位多67.00%。Margalef种类丰富度在1.20～6.20,平均3.35。污对中潮位桡足类群落的影响大于高潮位。

Influence of pollutants drained 0020z from land on copepods community structure in mudflats of Hangzhou Bay

In order to understand the spatial-temporal variation of copepod species composition,abundance and biodiversity,40 surveys were conducted at high tide level and middle tide level in the mudflat wetlands of the Hangzhou Bay.The samples were collected at 5 profiles(S1 to S5) in Apr.(spring),Jun.(summer),Oct.(autumn) 2010 and Jan.(winter) 2011.A total of 19 species belonging to 3 orders(7 Cyclopoida,5 Calanoida and 7 Harpacticoida),of which 8 species were freshwater ecological type,11 species were brackish-water type,were identified.According to the annual average abundance and Occurrence frequency of various copepod species,the dominant ones were Sinocalanus dorrii,Tachidius triangularis and Thermocyclops taihokuensis,all belonging to the freshwater ecological type.The community abundance of copepods ranged between 2.64~39.16 /L with an average of 13.54 /L.Copepod biomass ranged between 0~2.078 mg/L with an average of 0.164 mg/L.Calanoida abundance and biomass accounted alone for 29.32% and 79.88% of the total copepods,respectively.The seasonal differences in abundance and biomass are as follows: spring>autumn>summer>winter.Over a one year period abundance and biomass were distributed such that S3>S2>S1>S5>S4.The middle tide level exceeded 67.00% in abundance compared to the figures for the high tide level in profiles S2.The value of Margalef′s richness index(d) was between 1.20~6.20,averaged 3.35.Influence of pollution water drained from land away on copepods community was more serious in middle tide level than that in high tide level.