投饵养鱼对潘家口水库藻类生长影响的围隔试验研究

设置投饵、投饵单养花鲢（Aristichthisnobilis）、投饵单养鲤鱼（Cyprinuscarpio）、投饵混养花鲢和鲤鱼以及空白对照5个围隔及水库背景水体,研究投饵养鱼对潘家口水库浮游藻类生长和群落结构的影响。结果发现,试验期间水库水体和空白对照围隔中总藻平均密度分别为2.60×10^6L^-1和3.38×10^6L^-1,均以蓝藻和绿藻为主且基本保持稳定状态;投饵能有效促进藻类生长,只投饵围隔中总藻平均密度达到1.17×10^8L^-1,藻种组成向单一鱼腥藻（Anabaena）方向演替;养殖花鲢抑制藻的生长,参照只投饵围隔,抑制率接近80%,绿藻占据极大优势,其中栅藻（Scenedesmussp）、芒锥藻（Errerellabornhemiensisconr）和空星藻（Coelastrumsp）成为优势藻种;投饵养殖鲤鱼也能有效降低藻生物量,总藻平均密度为4.07×10^7L^-1,绿藻占总藻的比例由27%增加到95%,其中空星藻和小球藻（ChlorellavulgarisBeij）为优势藻种;投饵混养花鲢和鲤鱼围隔中总藻密度稍高于单养花鲢和鲤鱼围隔,为4.37×10^7L^-1,栅藻和鱼腥藻为优势藻种。

Experimental research on algae with fish culturing in the Panjiakou reservoir by the use of enclosures

In order to explore the effect of fish culturing on the phytoplankton growth and its community structure in the Panjiakou Reservoir,enclosure experiments were conducted with six different designs：background reservoir water;fish food addition without fish;fish food addition with bighead carp（Aristichthis nobilis）;fish food addition with common carp（Cyprinus carpio）;fish food addition with bighead carp and common carp;control without any fish food and fish.During the experimental period,it is found that Cyanophyta and Chlorophyta were the dominant algae species in the background water as well as the control enclosure,and the total average biomass reached to 2.60×10^6 L^-1 and 3.38×10^6 L^-1,respectively.Compared to the background reservoir water and control,single fish food can greatly encourage the phytoplankton growth,and Anabaena tend to predominate the phytoplankton community structure with the total average biomass of 1.17×10^8 L^-1.Presence of bighead carp restrained the phytoplankton growth with the maximal inhabitation ratio of approximately 80 % in contrast to the single addition of fish food,and Chlorophyta mainly including Scenedesmus sp,Coelastrum sphaericum Nag,Errerella was the dominant phytoplankton species.In the common carp culturing enclosure,total alga biomass concentration was slightly higher than that measured in single bighead carp or common carp culturing enclosure,and Chlorophyta mainly consisted of Coelastrum sp and Chlorella vulgaris Beij was the dominant phytoplankton species,which accounted for nearly 95% of the total biomass with the value of 4.07×10^7 L^-1.Furthermore,in the mixed culturing enclosure,Anabaena and Scenedesmus sp became the predominant algae species with the total biomass of 4.37×10^7 L^-1.