龙羊峡水库虹鳟养殖网箱附着藻类群落结构、附着过程与分布特征研究

Study on the community structure,attachment process and distribution characteristics of algae attached to rainbow trout cages in Longyangxia reservoir

龙羊峡水库作为全国最重要的虹鳟鱼网箱养殖基地,养殖网箱附着藻类显著增加了其养殖成本。本文通过形态学和分子生物学手段,分析龙羊峡水库养殖网箱附着藻类的丝状优势种,采用挂网法和挂板法研究附着藻类生物量的时空分布特征及其附着过程。结果表明:(1)龙羊峡水库共检出附着藻类5门31属,丝状藻类优势种主要为水绵(Spirogyra sp.),群落种类、数量组成均以硅藻门(Bacillariophyta)和绿藻门(Chlorophyta)为主。(2)龙羊峡水库养殖网箱附着过程与其他淡水水域附着过程相似,呈现有机物—细菌、真菌、小微型藻类—丝状绿藻的附着过程,但在具体物种上存在差别,体现了高原冷水性湖泊附着藻类的组成特点。(3)附着藻类生物量呈现夏季多,春秋次之,冬季最少的分布趋势;在垂直方向上主要分布于水体表层0~3 m处。该研究结果可为黄河上游养殖网箱附着藻类的防控提供参考。

The filamentous dominant species of algae attached to rainbow trout cages in Longyangxia reservoir are determined by morphological and molecular biology methods.The spatiotemporal distribution characteristics and attachment process of the attached algae are studied by hanging net method and hanging plate method.The results show that:(1)A total of 5 phyla and 31 genera of the attached algae are detected in Longyangxia reservoir.The filamentous dominant species of algae attached to the reservoir are Spirogyra sp.,and the community species are mainly Bacillariophyta and Chlorophyta.(2)The algae attachment process of rainbow trout culture cages in the reservoir is similar to that of other freshwater waters,showing the attachment process of organic matter—bacteria,fungi,small and micro algae—filamentous green algae.However,there are differences in specific species,reflecting the composition characteristics of the attached algae in plateau cold water lakes.(3)The biomass of the attached algae is more in summer,followed by spring and autumn,and the least in winter;it is mainly distributed at 0~3 m of water surface in the vertical direction.The research results can provide a reference for the prevention and control of algae adhering to cage culture in the upper reaches of the Yellow River.