Du Xue, Song Dan, Wang Huibo, Yang Jingshuang, Liu Hui, Huo Tangbin
Key Laboratory of Aquatic Organism Protection and Ecological Restoration in Cold Waters, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, China.
Heilongjiang River Basin Fisheries Ecology Observation and Research Station of Heilongjiang Province, Harbin, China.
Front Plant Sci. 2023 Jan 23;14:1069593. doi: 10.3389/fpls.2023.1069593. eCollection 2023.
Freshwater ecosystems are threatened by eutrophication, which causes persistent and harmful algal blooms. Filter-feeding bivalve mollusks and submerged macrophytes (SMs) alleviate the eutrophication effects by inhibiting phytoplankton biomass blooms. However, very little is known about whether and how the combined manipulation of filter-feeding bivalves and SMs control eutrophication and influence phytoplankton assemblages. Here, we performed a nutrient-enriched freshwater mesocosm experiment to assess the combined effects of the filter-feeding bivalve , a cockscomb pearl mussel, and the macrophyte on the biomass and composition of phytoplankton assemblages. We found that addition of and decreased the water nutrient concentrations and suppressed overall phytoplankton biomass. Further, distinct differences in taxa between restoration and control treatments were observed and noticeably competitive exclusion of cyanobacteria in the restoration treatments occurred. An antagonistic interaction between filter-feeding bivalves and SMs was only detected for total cyanobacteria biomass demonstrating that a larger magnitude of SM restoration may override the effect of filter-feeding bivalves. Our results suggest that manipulation, through the addition of bivalves as grazers, associated with the restoration of SMs, is an efficient approach for reducing cyanobacterial blooms and alleviating eutrophication.
淡水生态系统受到富营养化的威胁，富营养化会导致持续且有害的藻华。滤食性双壳贝类和沉水大型植物（SMs）通过抑制浮游植物生物量的藻华来减轻富营养化的影响。然而，对于滤食性双壳贝类和SMs的联合操控是否以及如何控制富营养化并影响浮游植物群落，人们所知甚少。在此，我们进行了一项营养富集的淡水围隔实验，以评估滤食性双壳贝类（鸡冠珠蚌）和大型植物对浮游植物群落生物量和组成的联合影响。我们发现，添加鸡冠珠蚌和大型植物降低了水体营养浓度，并抑制了浮游植物的总体生物量。此外，在恢复处理和对照处理之间观察到了分类群的明显差异，并且在恢复处理中明显出现了对蓝藻的竞争性排斥。仅在总蓝藻生物量方面检测到滤食性双壳贝类和SMs之间存在拮抗相互作用，这表明更大程度的SM恢复可能会抵消滤食性双壳贝类的作用。我们的结果表明，通过添加作为食草动物的双壳贝类并结合SMs的恢复进行操控，是减少蓝藻藻华和减轻富营养化的有效方法。
