Biomanipulation is an efficient tool to control eutrophication and cyanobacterial blooms in temperate lakes. However, the effects of this technique are still unclear for tropical ecosystems. Herein, we evaluated the effects of the biomanipulation on cyanobacterial biomass in a tropical shallow reservoir in Northeast Brazil. A mesocosm experiment was conducted in Tapacurá reservoir (Pernambuco) with eight treatments, in which we factorially manipulated the presence of submerged macrophytes (Ceratophyllum demersum), large herbivorous zooplankton (Sarsilatona serricauda), and nutrients (0.4 mg L⁻¹ of nitrogen and 0.5 mg L⁻¹ of phosphorus). On the first, fifth, and tenth days, we analyzed the total biomass of cyanobacteria, and the morphotypes coccoid, heterocyted filamentous, and non-heterocyted filamentous cyanobacteria; these components were compared through a three-way ANOVA. The bloom was composed mainly of five Microcystis morphospecies (coccoids) and Raphidiopsis raciborskii (heterocyted filaments). On the fifth day of the experiment, the combined addition of macrophytes and zooplankton was more efficient at controlling cyanobacterial biomass. On the tenth day, all macrophyte treatments showed significant cyanobacterial biomass reduction, decreasing up to 84.8%. On the other hand, nutrients and zooplankton, both isolated and combined, had no significant effect. Macrophytes also reduced the biomass of coccoids, heterocyted filaments, and non-heterocyted filaments when analyzed separately on the tenth day. Ceratophyllum demersum was more efficient at controlling the bloom than the addition of large herbivorous zooplankton, which could be related to allelopathy since cyanobacterial biomass was also reduced when nutrients were added. The addition of submerged macrophytes with allelopathic potential, associated with the increase of large herbivorous zooplankton, proved to be an efficient technique for controlling tropical cyanobacterial blooms.

生物操纵是控制温带湖泊富营养化和蓝藻水华的有效工具。但是，对于热带生态系统，这种技术的效果仍然不清楚。在这里，我们评估了生物操纵对巴西东北部一个热带浅水库中的蓝细菌生物量的影响。在Tapacurá水库（伯南布哥州）进行了八次处理的中观试验，在其中我们分析了淹没的大型植物（Ceratophyllum demersum），大型草食性浮游动物（Sarsilatona serricauda）和养分（0.4 mg L ^-1的氮和0.5的氮）的存在。毫克每升^-1磷）。在第一天，第五天和第十天，我们分析了蓝细菌的总生物量，以及球虫，异种丝状和非异细胞丝状蓝细菌的形态类型。通过三因素方差分析比较这些成分。水华主要由5个微囊藻的形态（球状）和Raphidiopsis raciborskii组成。（异细胞丝）。在实验的第五天，大型植物和浮游动物的联合添加在控制蓝藻生物量方面更为有效。在第十天，所有大型植物处理均显示蓝藻生物量显着减少，最多减少84.8％。另一方面，营养物质和浮游动物，无论是分离的还是结合的，都没有明显的作用。当在第十天分别进行分析时，大型植物还减少了类球体，杂细胞丝和非杂细胞丝的生物量。角藻与添加大型草食性浮游动物相比，在控制开花方面更有效，这可能与化感作用有关，因为添加营养素后蓝细菌的生物量也会减少。添加具有化感潜能的沉水大型植物，与大型草食性浮游动物的增加有关，被证明是控制热带蓝细菌开花的有效技术。