EXPERIMENTAL STUDIES ON THE ROLE OF PLANKTIVOROUS FISHES IN THE ELIMINATION OF MICROCYSTIS BLOOM FROM DONGHU LAKE USING ENCLOSURE METHOD

The hypertrophic subtropic Donghu Lake's dense water bloom(of mainly Microcystis Anaabaena andOscillatoria)that occurred annually from the beginning of the 1970s, has disappeared since 1985. The infiuenceof planktivorous fishes (silver and bighead carps) on the water bloom was studied for three years usingthe enclosure method. The enclosures stocked densely with bighead and/or silver carp were free of waterbloom during the experimental period. The water bloom that appeared in the fish-free enclosures was completelyeliminated in 10-20 days by introduction of silver and/or bighead carp(grass carp was not effectivein controlling water bloom).This study showed clearly that grazing pressure by planktivorous fishes is a keyfactor in eliminating water bloom from the lake.     

Effect of enclosure and nutrient enrichment on Microcystis blooms in Donghu Lake

1 INTRODUCTION Surface blooms of nuisance cyanobacteria are often a signal of eutrophication (Jacoby et al., 2000). They are generally favored by conditions of low nitrogen to phosphorus ratios, high total phosphorus content, high water temperature, high …     

Preliminary studies on the role of protozoa in the food web of Donghu Lake

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融合面向对象和分水岭算法的山地湖泊提取方法

面向对象的方法提取湖泊,常常面临边界识别不精确的问题.本研究在面向对象方法的基础上,利用分水岭算法,解决湖泊边界识别问题.该方法初步将遥感影像划分为确定湖泊区域、潜在湖泊区域和背景;然后通过分水岭算法对潜在湖泊区域进行二次提取.研究选择昆仑-喀喇和喜马拉雅山脉区域的3个山地湖泊发育良好的区域作为实验区,利用Landsa...