Department of Ecology, Center for Biosciences, Federal University of Rio Grande do Norte, RN, Brazil.
Center for Environmental and Climate Research, Lund University, Lund, Sweden; Department of Biology, Lund University, Lund, Sweden.
Harmful Algae. 2016 Apr;54:128-144. doi: 10.1016/j.hal.2015.12.005.
As blooms of cyanobacteria expand and intensify in freshwater systems globally, there is increasing interest in their ecological effects. In addition to being public health hazards, cyanobacteria have long been considered a poor quality food for key zooplankton grazers that link phytoplankton to higher trophic levels. While past laboratory studies have found negative effects of nutritional constraints and defensive traits (i.e., toxicity and colonial or filamentous morphology) on the fitness of large generalist grazers (i.e., Daphnia), cyanobacterial blooms often co-exist with high biomass of small-bodied zooplankton in nature. Indeed, recent studies highlight the remarkable diversity and flexibility in zooplankton responses to cyanobacterial prey. Reviewed here are results from a wide range of laboratory and field experiments examining the interaction of cyanobacteria and a diverse zooplankton taxa including cladocerans, copepods, and heterotrophic protists from temperate to tropical freshwater systems. This synthesis shows that longer exposure to cyanobacteria can shift zooplankton communities toward better-adapted species, select for more tolerant genotypes within a species, and induce traits within the lifetime of individual zooplankton. In turn, the function of bloom-dominated plankton ecosystems, the coupling between primary producers and grazers, the stability of blooms, and the potential to use top down biomanipulation for controlling cyanobacteria depend largely on the species, abundance, and traits of interacting cyanobacteria and zooplankton. Understanding the drivers and consequences of zooplankton traits, such as physiological detoxification and selective vs. generalist grazing behavior, are therefore of major importance for future studies. Ultimately, co-evolutionary dynamics between cyanobacteria and their grazers may emerge as a critical regulator of blooms.
随着蓝藻在全球淡水系统中的爆发和加剧，人们对其生态影响的兴趣日益增加。除了对公众健康构成威胁外，蓝藻长期以来一直被认为是关键浮游动物摄食者的劣质食物，这些动物将浮游植物与更高的营养层次联系起来。虽然过去的实验室研究发现，营养限制和防御特性（即毒性和群体或丝状形态）对大型广食性摄食者（如桡足类）的适应性有负面影响，但在自然界中，蓝藻水华通常与小体型浮游动物的高生物量共存。事实上，最近的研究强调了浮游动物对蓝藻猎物的反应的显著多样性和灵活性。本文综述了一系列广泛的实验室和野外实验的结果，这些实验研究了蓝藻和包括有甲目、桡足类和异养原生动物在内的各种浮游动物类群在从温带到热带淡水系统中的相互作用。这一综合研究表明，较长时间接触蓝藻可以使浮游动物群落向适应性更强的物种转移，在一个物种内选择更具耐受性的基因型，并在个体浮游动物的生命周期内诱导出特征。反过来，以水华为主的浮游动物生态系统的功能、初级生产者和摄食者之间的耦合、水华的稳定性以及利用自上而下的生物操纵来控制蓝藻的潜力，在很大程度上取决于相互作用的蓝藻和浮游动物的物种、丰度和特征。因此，了解浮游动物特征（如生理解毒和选择性与广食性摄食行为）的驱动因素和后果对于未来的研究非常重要。最终，蓝藻与其摄食者之间的共同进化动态可能成为水华的一个关键调节因素。
