Kutser Tiit, Soomets Tuuli
Estonian Marine Institute, University of Tartu, Mäealuse 14, 12618, Tallinn, Estonia.
Sci Rep. 2024 Jun 22;14(1):14391. doi: 10.1038/s41598-024-65250-7.
Lakes are a crucial source of drinking water, provide ecological services from fisheries and aquaculture to tourism and are also a critical part of the global carbon cycle. Therefore, it is important to understand how lakes are changing over time. The ESA Ocean Colour Climate Change Initiative (OC-CCI) database allows to study changes in the largest lakes over 1997-2023 period. The Caspian Sea and ten next largest lakes were under investigation. Changes in the phytoplankton biomass (Chl-a), the concentration of particulate matter (b(555)), the colored dissolved organic matter, CDOM (a(412)), and the light diffuse attenuation coefficient in water (K(490)) were analyzed. Both increasing and decreasing trends (or no significant trend at all) of studied parameters were observed in these lakes over the study period. In some of the Laurentian Great Lakes the changes in CDOM over the study period were found to be in accordance with the lake water level changes i.e. with the inflow from the catchment. There was difference between the trends of Chl-a and b(555) in lakes Michigan and Huron indicating that there may have been shift in phytoplankton community that took place around 2005. The study demonstrated that remote sensing products, like the ones created by ESA OC-CCI, are valuable tools to study behavior of large lakes ecosystems over time.
湖泊是重要的饮用水源，提供从渔业、水产养殖到旅游业等多种生态服务，也是全球碳循环的关键组成部分。因此，了解湖泊如何随时间变化非常重要。欧洲航天局海洋颜色气候变化倡议（OC-CCI）数据库有助于研究1997年至2023年期间最大湖泊的变化情况。里海和接下来的十个最大湖泊都在研究范围内。分析了浮游植物生物量（叶绿素a）、颗粒物浓度（b(555)）、有色溶解有机物（CDOM，a(412)）以及水中光散射衰减系数（K(490)）的变化。在研究期间，这些湖泊中研究参数呈现出上升、下降趋势（或根本没有显著趋势）。在一些五大湖地区，研究发现研究期间CDOM的变化与湖泊水位变化一致，即与流域的水流情况一致。密歇根湖和休伦湖的叶绿素a和b(555)趋势存在差异，这表明2005年左右浮游植物群落可能发生了变化。该研究表明，像欧洲航天局OC-CCI创建的这类遥感产品，是研究大型湖泊生态系统随时间变化行为的宝贵工具。
