Experimental studies on the role of planktivorous fishes in the elimination ofMicrocystis bloom from Donghu Lake using enclosure method

The hypertrophic subtropic Donghu Lake's dense water bloom (of mainlyMicrocystis, Anabaena andOscillatoria) that occurred annually from the beginning of the 1970s, has disappeared since 1985. The influence of planktivorous fishes (silver and bighead carps) on the water bloom was studied for three years using the enclosure method. The enclosures stocked densely with bighead and/or silver carp were free of water bloom during the experimental period. The water bloom that appeared in the fish-free enclosures was completely eliminated in 10–20 days by introduction of silver and/or bighead carp(grass carp was not effective in controlling water bloom). This study showed clearly that grazing pressure by planktivorous fishes is a key factor in eliminating water bloom from the lake. This work was supported by FEBL (State Key Laboratory for Freshwater Ecology and Biotechnology of China) funds and by the National Natural Science Foundation of China (Grant No., 3937014).     

ENCLOSURE EXPERIMENTS ON AND LACUSTRINE PRACTICE FOR ELIMINATING MICROCYSTIS BLOOM

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SESTON AND DISSOLVED ORGANIC CARBON DYNAMICS DURING MICROCYSTIS BLOOM WITH SPECIAL REFERENCE TO THE EFFECTS OF THREE CHINESE DOMESTIC FISHES IN EXPERIMENTAL ENCLOSURES

ImODUonONGrowingconcemovertheprobboofobnoxiouswaterbloornspromPtedagreatdealofresearchintothebiologyofblue-grmalgae(Reynolds&Walsby,l975,Reynothe,l984).PreviousstudiesonMimptiSwereaimedatitSphySinlogicalcharaCteristirsindudinggroWthandbuoyancyraegnolds,l975),0Vendteringandphotosynthesisfea-turesffokamuraetal.,l984,Takamura,l985),nutrientdemandsoprlofTetal.,l952,0kado&Sudo,l979).TherearerepoffethatMicropstiswasawidelydistributalspedesthatcouldeasilybloomWhenambientenvironrnentSweresuit…