Aquatic Ecology Laboratory, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1314 Kinnear Rd., Columbus, OH, 43212, USA.
Aquatic Ecology Laboratory, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1314 Kinnear Rd., Columbus, OH, 43212, USA.
Harmful Algae. 2020 Feb;92:101586. doi: 10.1016/j.hal.2019.03.004. Epub 2019 Oct 16.
With anthropogenic eutrophication and climate change causing an increase in cyanobacterial blooms worldwide, the need to understand the consequences of these blooms on aquatic ecosystems is paramount. Key questions remain unanswered with respect to how cyanobacteria blooms affect the structure of aquatic food webs, the foraging abilities of higher consumers, and the potential for cyanotoxins (e.g., microcystins [MCs]) to accumulate in fish. Toward addressing these uncertainties, physicochemical attributes, water (for MCs), phytoplankton, zooplankton, and epipelagic and benthic age-0 fish were sampled at 75 sites (44 sites for fish) of varying cyanobacteria concentration (0.1-44 μg/L) in western Lake Erie during the cyanobacteria bloom season, 2013-2014. Sites with high cyanobacteria biomass were characterized by Microcystis spp. (84-100% of biomass), detectible levels of MCs (maximum = 10.8 μg/L), and low water transparency (minimum = 0.25 m). Counter to expectations, strong positive relationships were found between cyanobacteria concentration and the biomass of several herbivorous zooplankton taxa (e.g., Daphnia, Diaphanosoma spp., Bosmina (formerly Eubosmina) coregoni, and Calanoida spp.). Expectations regarding fish were partly supported (e.g., diet selectivity varied across a cyanobacteria gradient) and partly not (e.g., consumption of zooplankton did not differ between bloom and non-bloom sites). These findings show that cyanobacterial blooms can strongly affect the distribution, composition, and interactions of zooplankton and fish, sometimes in surprising ways, highlighting the need to further explore their impact on aquatic food webs.
随着人为富营养化和气候变化导致全球蓝藻水华的增加，了解这些水华对水生生态系统的影响至关重要。关于蓝藻水华如何影响水生食物网的结构、高级消费者的觅食能力以及蓝藻毒素（如微囊藻毒素 [MCs]）在鱼类中积累的潜力等关键问题仍未得到解答。为了解决这些不确定性，在 2013-2014 年蓝藻水华季节，在西伊利湖的 75 个地点（鱼类 44 个地点）采集了具有不同蓝藻浓度（0.1-44μg/L）的理化特性、水（用于 MCs）、浮游植物、浮游动物以及上覆层和底栖 0 龄鱼。高蓝藻生物量的地点的特征是微囊藻属（84-100%的生物量）、可检测到的 MCs 水平（最高值=10.8μg/L）和低水透明度（最小值=0.25m）。与预期相反，在蓝藻浓度与几个草食性浮游动物类群（如桡足类、双甲藻属、裸腹溞和哲水蚤科）的生物量之间发现了强烈的正相关关系。对鱼类的预期得到了部分支持（例如，饮食选择性在蓝藻梯度上有所不同），部分未得到支持（例如，在水华和非水华地点之间，浮游动物的消耗没有差异）。这些发现表明，蓝藻水华可以强烈影响浮游动物和鱼类的分布、组成和相互作用，有时以令人惊讶的方式，强调需要进一步探索它们对水生食物网的影响。
