机构地区:[1]武汉大学资源与环境科学学院,武汉430079
出 处:《水生态学杂志》2015年第2期39-45,共7页Journal of Hydroecology
基 金:国家"十二.五"水专项;水体污染控制与治理科技重大专项"洱海水污染防治;生境改善与绿色流域建设技术及工程示范项目"课题四之子课题"洱海浮游动物控藻机制及增殖保育技术"(2012ZX07105-004-002-001)
摘 要:浮游动物摄食藻类是生物操控藻类水华的基础理论,条件适宜时浮游动物能够发挥一定的控藻作用。以拟老年低额溞(Simocephalus vetuloides)、大型溞(Daphnia magna)以及栅藻(Scenedesmus obliquus)、铜绿微囊藻(Microcystis aeruginosa)无毒株CHAB109和有毒株PCC7806为实验对象,通过设计不同的藻类密度、光照条件和浮游动物密度,研究了浮游动物对藻类的摄食关系及其影响因素。结果表明,当栅藻和无毒铜绿微囊藻CHAB109密度均为1.02×106个/m L时,拟老年低额溞对二者的去除率分别为54.20%和6.45%,大型溞为49.77%和64.77%;拟老年低额溞对栅藻和CHAB109混合藻液中的2种藻均有较好的去除效果,去除率分别为60.65%和34.43%,高于对纯种藻的去除率;在遮光条件下,浮游动物摄食量更大,对藻的去除效果更优,拟老年低额溞在锡箔遮光情况下,对初始藻细胞密度为3.023×105个/m L的有毒微囊藻PCC7806去除率达到32.37%。7日龄的浮游动物个体大,摄食量也大,有较好的去除效果,且随着浮游动物数量的增加,去除率也随着提高。高密度的藻细胞对2种浮游动物存活率的影响较低密度大。当选用浮游动物控制藻类水华时,需综合考量选用的种类、大小、添加数量等因素。Foraging of algae by zooplankton is the basic principle behind the use of biomanipulation to controll algal blooms. Daphnia is an important fauna in the freshwater food chain and much research has been carried out on its use for controlling phytoplankton. Microcystis aeruginosa produces toxic-algae blooms in warm eutrophic waters and,because blooms tend to be long lasting and hard to control,research has focused on prevention and control of aglae blooms. The representative algal species Microcystis aeruginosa( non-toxic CHAB109; toxic PCC7806) and Scenedesmus obliquus and the large zooplankton species Simocephalus vetuloides and Daphnia magna were chosen to study zooplankton grazing on algal growth and the factors that influence grazing in order to verify the feasibility and effectiveness of different zooplankton species in controlling of algae bloom. Foraging trials were run under different algal densities,light conditions and zooplankton densities. Zooplankton and phytoplankton in all trials were sampled and analyzed each day at the same time. Results indicate that the removal rates of Scenedesmus obliquus and CHAB109 in Scenedesmus obliquus group and CHAB109 group( both initial density of 1. 02 × 10^6 cells / m L) were54. 20% and 6. 45% by Simocephalus vetuloides,and 49. 77% and 64. 77% by Daphnia magna. The removal rates of Scenedesmus obliquus and CHAB109 in mixture group of Scenedesmus obliquus with CHAB109 were 60. 65%and 34. 43% by Simocephalus vetuloides,higher than those in single algae groups. The results also reveal that zooplankton consumed larger amount of algae and displayed more effective removal of algae in the dark. The removal rate of PCC7806 with an initial density of 3. 023 × 10^5 cells / m L was 32. 37% by Simocephalus vetuloides under aluminium foil shading. In the trials,mature Daphnia magna( 7 d) had higher removal rates than the larvae due to the larger size and greater need for food and the removal rate increased with zooplankton density. However,the growth of zooplankton
分 类 号:X171.4[环境科学与工程—环境科学]
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