Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, Wageningen, The Netherlands.
Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland Research, Radboud University, Nijmegen, The Netherlands.
PLoS One. 2020 Mar 11;15(3):e0229148. doi: 10.1371/journal.pone.0229148. eCollection 2020.
Lake Lesser Prespa in Greece is a vital breeding habitat for the Dalmatian and Great White Pelican and a shelter for numerous rare and endemic species. However, eutrophication processes are distressing the lake system and the outbreaks of cyanobacterial blooms during the warm months may pose a threat to aquatic organisms due to the presence of microcystins (MCs). In this study we hypothesize that nutrients (eutrophication), nutrient-rich pelican droppings (guanotrophication) and warming (climate change) can affect the algal growth and MCs production in the water layer of Lake Lesser Prespa. Seston collected from three lake sites was incubated at ambient (20°C) and high (30°C) temperature with or without the addition of nutrients (nitrogen (N), phosphorus (P)), or pelican droppings. Results showed increased chlorophyll-a at higher temperature (30°C). N addition yielded higher chlorophyll-a levels than the non-treated water or when only P was added. The addition of both N and P as well as the addition of pelican dropping resulted in the highest chlorophyll-a at both temperatures. Notably, in the dropping-treatments, cyanobacteria and MCs were promoted while changes were evoked in the relative contribution of toxic MC-variants. Guanotrophication may thus influence the cyanobacterial dynamics and most likely their toxicity profile at Lesser Prespa.
希腊的小普雷斯帕湖是达尔马提亚鹈鹕和大鹈鹕的重要繁殖栖息地，也是众多珍稀和特有物种的避难所。然而，富营养化过程正在困扰着这个湖泊系统，并且在温暖的月份，蓝藻水华的爆发可能由于存在微囊藻毒素（MCs）而对水生生物构成威胁。在本研究中，我们假设营养物质（富营养化）、富含营养的鹈鹕粪便（鸟粪营养化）和升温（气候变化）会影响小普雷斯帕湖水层中的藻类生长和 MCs 产生。从三个湖点采集的悬浮物在环境（20°C）和高温（30°C）下进行孵育，有或没有添加营养物质（氮（N）、磷（P）），或鹈鹕粪便。结果表明，在较高温度（30°C）下，叶绿素 a 增加。与未经处理的水或仅添加 P 相比，N 添加产生了更高的叶绿素 a 水平。在两种温度下，添加 N 和 P 以及添加鹈鹕粪便都会导致最高的叶绿素 a。值得注意的是，在粪便处理中，蓝藻和 MCs 得到了促进，而有毒 MC 变体的相对贡献发生了变化。因此，鸟粪营养化可能会影响小普雷斯帕湖的蓝藻动态及其毒性特征。
