三都澳大型底栖动物次级生产力

为了解中国海沿岸典型密集养殖区——三都澳水域大型底栖动物次级生产力水平和时空分布特点,于2009年5月至2010年2月共9个航次在三都澳20个观测站采集底栖动物定量样品,利用Brey经验公式对大型底栖动物次级生产力和P/B值进行研究计算。结果表明,该海域大型底栖动物年平均栖息密度为121.52 ind.m-2,年平均生物量以去灰干重(AFDW)计]为1.26 g(AFDW).m-2,年平均次级生产力为1.67 g(AFDW).m-2.a-1,P/B值为1.42。三都澳大型底栖动物次级生产力空间分布呈现出湾口区较高、湾内部高值区镶嵌分布的特征。相关分析表明,不同环境因子间,次级生产力与水深之间相关性较强,其次为底层溶解氧,与表层水体温度之间相关性最差。同我国其它近海港湾相关研究结果比较显示,三都澳密集养殖区大型底栖动物年平均生物量和次级生产力水平较低,但年平均栖息密度较高。这些特征应和三都澳水域内密集水产养殖活动关系密切。

Secondary productivity of macrobenthos in Sandu Bay

In order to understand the actuality of macrobenthic assemblages in Sandu Bay,one of the most typical extensive mariculture in coastal waters of the East China Sea,the secondary productivity with Brey’s(1990) empirical formula was calculated,based on the data obtained from 9 cruises of 20 stations from May 2009 to February 2010.The results showed that the mean abundance and biomass in the Sandu Bay during the period were 121.52 ind·m-2 and 1.26 g(AFDW)·m-2,respectively.The mean annual secondary productivity in the study area was 1.67 g(AFDW) ·m-2·a-1.The average annual macrobenthic P/B ratio was 1.42.Sampling stations with high secondary productivity were mainly located in areas near the mouth of the Sandu Bay,while those in middle and inner parts of the bay were sparsely distributed.Distribution characters of secondary productivity in Sandu Bay were more closely correlated with the depths,and consequently,with the dissolved oxygen level in bottom waters.Comparing the results of the present study with other similar studies,it was revealed that macrobenthic assemblages in the Sandu Bay exhibited relatively lower average annual biomass and secondary productivity,but with higher annual average abundance.This phenomenon was considered to be results of influences of intensive mariculture activities in this area.