湖泊科学2019，Vol.31Issue(2)：386-396,11.DOI:10.18307/2019.0208
富营养化初期湖泊放养鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)控藻生态效果的初步评估
Preliminary evaluation of ecological effects of silver and bighead carps to control cyanobacterial blooms in the early eutrophication lakes
摘要
Abstract
It is one of the most effective ways to control the outbreak of cyanobacteria blooms in eutrophic lakes by stocking silver and bighead carps. In order to evaluate the ecological effects of controlling algae by silver and bighead carps in early eutrophication lakes. In 2016, a little biomanipulation in-situ pen with the stock of silver and bighead carps was built to control cyanobacterial blooms in Hongshan Bay of Lake Erhai. The changes of plankton community structure and water environmental factors were compared and analyzed within and outside the pen. Meanwhile, the growth and feeding rhythm of silver and bighead carps were measured. The pen-cultured silver and bighead carp all displayed normal growth, the survival environment of the pen is suitable. Daily rations of silver and bighead carp were estimated by Egger's model in the main growing season. Filtration rate was calculated from the daily ration and the density plankton in the lake. Daily rations of silver and bighead carp was 24.96％ and 18.18％. The daily rations silver carp is higher than that of bighead carp. Filtration rates of silver and bighead carp for phytoplankton were 3.01 L/ (g·h) and 2.19 L/ (g·h) , respectively, and filtration rates for zooplankton were 13.54 L/ (g·h) and 18.61 L/ (g·h) , respectively. Silver carp had a stronger ability of eliminating phytoplankton than bighead carp. Bighead carp had a stronger ability of eliminating zooplankton than silver carp. During the study, there was no significant difference in the environmental parameters within and outside the pen. The biomass of Microcystis reached its peak in July (1.7 mg/L in the fish pen and 2.4 mg/L in the surrounding lake water) . The Microcystis biomass was significantly lower in the pen. The present stocking density of silver and bighead carp (about 20 g/m3 in June) was effective to control Microcystis. From June to August, the reduction rate of the phytoplankton in the silver and bighead carp gradually increased, and the rate of reduction was up to 64％ in August. When phytoplankton's dominant species Chlorophyta and diatom replace Microcystis, the rate of reduction decreased gradually, with negative values in October and November. Furthermore, the biomass of crustacean zooplankton biomass and cladocerans biomass were significantly lower in the pen.Therefore, in combination with several experimental results, silver carp had a stronger ability of eliminating phytoplankton than bighead carp. Especially for Microcystis blooms, silver carp at the same time have the higher on the reduction ability of crustacean zooplankton. We need to further analyze the suitability of non-traditional biological manipulation in the early stage of eutrophication Lake Erhai.关键词
富营养化初期湖泊/鲢/鳙/浮游生物/蓝藻水华/摄食率/洱海Key words
Early eutrophication lakes/silver carp/bighead carp/plankton/cyanobacterial blooms/filtration rate/Lake Erhai引用本文复制引用
杨姣姣,过龙根,尹成杰,陈晓希,倪乐意..富营养化初期湖泊放养鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)控藻生态效果的初步评估[J].湖泊科学,2019,31(2):386-396,11.基金项目
国家水体污染控制与治理科技重大专项洱海项目(2012ZX07105-04)资助 （2012ZX07105-04）
