浙江三门湾贝类分布特征

The shellfish distribution in Sanmen Bay, Zhejiang

为探明三门湾贝类分布特征,于2002年6月至2003年5月4个季节在三门湾采集样品和分析,鉴定出贝类31种,年均生物量和年均密度为2.35g/m2,41个/m2,高生物量和高密度区主要分布于三门湾的湾顶区域(4.28g/m2,70个/m2),其它区域相对较低。贝类春季生物量和密度(3.55g/m2,97个/m2)>夏季(2.88g/m2,40个/m2)>秋季(2.18g/m2,16个/m2)>冬季(0.85g/m2,13个/m2),贝类多样性指数(H’)为0.92～1.93、均匀度指数(J)为0.64～1。通过海流、底质等因子的分析,以及调查海区与浙江其它海湾及邻近列岛水域的比较认为:随春季水温回升,三门湾贝类进入繁衍旺季,故春季密度分布很高,但受捕食、海流搬运和自然死亡等因素影响,至秋冬季三门湾贝类密度则趋于明显回落。

In order to reveal the shellfish distribution in Sanmen Bay ofZhejiang, a four-season field investigation was carded from Jun 2002 to May 2003. Samples were collected using HNM sampler. 31 shellfish species were identified. Mean annual biornass and mean annual density was 2.35 g/m^2 and 41 ind/m^2 respectively. The areas of high biornass and high density were mostly inside the upper bay （4.28 g/m^2, 70 ind/m^2）, and the lower biornass and density ones were in the other area. Biornass of different seasons is spring （3.55 g/m^2）〉 summer（2.88 g/m^2）〉fall（2.18 g/m^2）〉winter（0.85 g/m^2）, and density variation of different seasons is spring（97 ind/m^2）〉summer（40 ind/m^2） 〉fall（16 ind/m^2） 〉winter（13 ind/m^2）.