NETFRESH: Networking the response of freshwater ecosystems to environmental change

淡水生物多样性的下降速度远远超过海洋或陆地生物群落，但我们缺乏对其机理的理解。阐明导致这些损失的机制的关键是研究生态相互作用（例如，捕食、竞争、寄生、互惠），这些相互作用将环境变化转化为生物群落结构和功能的变化。然而，由于识别和量化水下环境中生态相互作用的技术限制，我们对淡水生态网络的了解仍然有限。在这里，我们提出了一个雄心勃勃的项目，发展我们量化淡水环境中生态相互作用的能力，目的是了解生态系统对环境变化的反应。我们将结合现有的（肠道含量分析，稳定同位素，产量估计）和新技术（元条形码，结合机器学习/人工智能的视频片段，宏量营养素）来实时探索生态相互作用。利用这些方法，我们将在流水中构建第一个多层生态网络（包括多种相互作用类型，如竞争、捕食、促进），并测试该框架在微观和中观尺度上检测生态系统变化的能力。对于后者，我们关注低流量作为淡水生态系统环境变化的关键组成部分——现有的机制理解围绕不同物种的个体水平反应（即，增加代谢需求）和围绕生态相互作用的潜在反应的明确假设（即，栖息地面积减少导致资源竞争加剧）。该项目将支持产生：(i)确定和量化淡水生态相互作用的新方法；（二）流动水体中生态相互作用的基础知识。此外，这项工作的发现还将有助于为国家监测战略提供信息，以更好地检测生态系统对环境变化的反应，并可以进一步开发方法，为淡水生态系统中的物种丧失和生态系统崩溃提供早期预警系统。

Biodiversity in freshwaters is declining at a rate far greater than marine or terrestrial biomes, yet we lack a mechanistic understanding. A key to elucidating the mechanisms driving these losses is the study of ecological interactions (e.g., predation, competition, parasitism, mutualism), which translate environmental change into alterations in the structure and function of biological communities. Our knowledge of ecological networks in freshwaters, however, remains limited due to technological constraints associated with identifying and quantifying ecological interactions in underwater environments.Here, we propose an ambitious project developing our ability to quantify ecological interactions in running freshwater environments with the aim of understanding ecosystem responses to environmental change. We will combine established (gut content analysis, stable isotopes, production estimates) and novel techniques (metabarcoding, video footage combined with machine learning/artificial intelligence, macronutrients) to explore ecological interactions in real time. Using these methods, we will construct the first multilayer ecological networks (networks including multiple interaction types, e.g., competition, predation, facilitation) in running waters, and test the ability of the framework to detect changes in ecosystems using micro- and meso-cosms. For the latter, we focus on low flows as a pivotal component of environmental change in freshwater ecosystems - with existing mechanistic understanding surrounding the individual-level responses of different species (i.e., increased metabolic demand) and clear hypotheses surrounding the potential responses of ecological interactions (i.e., reduced habitat size leads to increased resource competition).The project will support the generation of: (i) novel methods for identifying and quantifying ecological interactions in freshwaters; and (ii) fundamental knowledge on ecological interactions in running waters. Furthermore, findings from this work will also help to inform national monitoring strategies to better detect the response of ecosystems to environmental change and methods could be developed further to potentially provide an early warning system for species loss and ecosystem collapse in freshwater ecosystems.