信江干流浮游动物分布特征及水质评价

摘要

The species structure ,dominant groups and distribution of zooplankton in Xinjiang River were investigated in 2010 and 2011.There were 44 species of zooplankton ,in which rotifers (65.91%) were predom-inat.The density of zooplankton was 88~705 ind/L and the density of rotifers was of predominance .The tempo-ral distribution of zooplankton in the wet season was greater than that in the dry season ,the densities of roti-fers,cladocerans,copepods and protozoa accounted respectively for 69.6%,1.8%,22.3%and 6.3%in the wet period,and 74.8%,0.5%,17.8%and 6.9%in the dry period.It was found that the density of zooplankton was low in the middle section and high in the upper and lower sections ,with the maximum value in the Shangrao section ( monitoring point No .6) and the minimum value in the Qianshan section ( monitoring point No .5) .The quantity structure of zooplankton consisted of rotifers and copepods ,and the biomass structure consisted of co-pepods and cladocerans .Biodiversity and water quality assessment showed that the water in Xinjiang River was slightly to moderately polluted .%为研究信江干流的浮游动物的时空分布及与水质的关系，于2010年和2011年丰水期与枯水期对信江干流各监测断面中浮游动物类群的结构组成、优势类群及时空分布状况进行调查，结果表明：信江干流浮游动物共有4类44种，种类最多的是轮虫类，共有8科15属29种，占总数的65．91％；其余三类均测出5种。浮游动物时空分布不均匀，时间分布上浮游动物丰度丰水期显著高于枯水期，密度变化范围为88～705个/L，其中丰水期轮虫、枝角类、桡足类与原生动物密度分别占总数的69．6％、1．8％、22．3％与6．3％；枯水期轮虫、枝角类、桡足类与原生动物密度分别占总数的74．8％、0．5％、17．8％与6．9％。浮游动物密度在空间分布上呈现上、下游大，中游小的格局，最大值出现在6号监测断面上饶，最小值出现在5号监测断面铅山。信江中下游浮游动物数量结构主要由轮虫和桡足类组成，生物量结构则主要由桡足类和枝角类组成。生物多样性及水质综合评价为轻度污染至中度污染。