Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, the Netherlands.
Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, the Netherlands; Wildlife Ecology and Conservation Group, Wageningen University (WUR), Droevendaalsesteeg 2, 6708 PB Wageningen, the Netherlands.
Sci Total Environ. 2022 Feb 20;808:152156. doi: 10.1016/j.scitotenv.2021.152156. Epub 2021 Dec 3.
Wind-induced sediment resuspension in shallow lakes may enhance nutrient availability while reducing light availability for phytoplankton growth, thereby affecting the entire food-web. Lake restoration projects that reduce wind-induced resuspension are expected to enhance trophic transfer efficiencies, thereby improving food-web structure and functioning. Yet, reduced resuspension may also lead to lower nutrient concentrations in the water column, promote benthic algae development, reduce phytoplankton biomass production and thereby reduce secondary production by zooplankton. Lake Markermeer is a shallow delta lake in The Netherlands subject to wind-induced sediment resuspension. Restoration project Marker Wadden consists of newly built islands aiming to reduce sediment resuspension and promote higher trophic levels. Here, we tested the effects of reduced sediment resuspension on phytoplankton biomass build-up, benthic algae development, and zooplankton abundances at different temperatures in a 14-day indoor microcosm experiment. We used Marker Wadden sediment with three resuspension intensities combined with three temperatures, to also test effects of higher temperatures in shallow sheltered waters. Reduced sediment resuspension decreased nutrient concentrations and phytoplankton biomass build-up, while increasing light availability and enhancing benthic algae biomass development. Reduced sediment resuspension furthermore increased zooplankton biomass. Enhanced sediment resuspension and higher temperatures synergistically interacted, maintaining a high level of inorganic suspended solids. Our experimental results are in line with long-term seasonal observations from Lake Markermeer. Our findings demonstrate that for shallow lakes suffering from wind effects, measures such as Marker Wadden aimed at reducing sediment resuspension can be effective in restoring secondary production and supporting higher trophic levels.
风引起的浅湖底泥沙再悬浮会增加营养物质的可利用性，同时减少浮游植物生长所需的光照，从而影响整个食物网。预计减少风引起的再悬浮的湖泊恢复项目将提高营养物质的转移效率，从而改善食物网的结构和功能。然而，减少再悬浮也可能导致水柱中营养物质浓度降低，促进底栖藻类的生长，减少浮游植物生物量的产生，从而减少浮游动物的次级生产力。荷兰的马基尔梅雷尔湖是一个受到风引起的底泥再悬浮影响的浅水三角洲湖。马基尔沃登修复项目由新建造的岛屿组成，旨在减少底泥再悬浮并促进更高的营养水平。在这里，我们在 14 天的室内微宇宙实验中，测试了减少底泥再悬浮对浮游植物生物量积累、底栖藻类发育和不同温度下浮游动物丰度的影响。我们使用了马基尔沃登沉积物，结合三种再悬浮强度和三种温度，以测试浅水避风区更高温度的影响。减少底泥再悬浮降低了营养物质浓度和浮游植物生物量的积累，同时增加了光照的可用性，并增强了底栖藻类的生物量发展。减少底泥再悬浮还增加了浮游动物的生物量。增强的底泥再悬浮和更高的温度协同作用，维持了高水平的无机悬浮物。我们的实验结果与马基尔梅雷尔湖的长期季节性观测结果一致。我们的研究结果表明，对于受到风影响的浅湖，马基尔沃登等旨在减少底泥再悬浮的措施可以有效地恢复次级生产力，并支持更高的营养水平。
