The increasing occurrence of toxic cyanobacterial blooms, driven by anthropogenic nutrient pollution in freshwater ecosystems, threatens water security and quality for humans and animals worldwide and severely disrupts ecosystem balance. Therefore, the implementation of thorough monitoring strategies for cyanobacteria, along with evaluation of the risks of bloom incidents and a plan for prevention and control measures, is now required in water suppliers' water safety plans. The significant economic losses to water companies, fisheries, recreational activities and businesses caused by cyanobacterial blooms require greater attention from policymakers. A suite of in-lake control methods exists, but there is little guidance on their efficiency. Decreasing nutrient input from the catchment is crucial for long-term prevention/ reduction of blooms and would be possible by the transition towards a more sustainable, low-nutrient-leakage agriculture, but needs implementation strategies. The COST Action CA23160, titled “Effective Lake management: reducing cyanobacteria by actions in the catchment - CYANOACTION”, aims to increase and broaden capabilities throughout Europe for effective and sustainable management of water resources using a catchment-wide approach by creating a unique network of experts, end users and stakeholders. Gathering and distributing information on early warning detection methods and on the effectiveness of both long- and short-term control methods will underpin Decision Support Tools for water managers and authorities, ensuring the selection of appropriate methods for a specific waterbody. The overarching goal is a close integration of scientific knowledge and management practices to reduce cyanobacterial blooms, taking into account the distinct characteristics of the water body and its catchment, as well as regulations across Europe. CYANOACTION will protect human and environmental health by creating an interdisciplinary network of experts, living labs, stakeholders, managers and decision-makers. Total project budget: ~600K€. NCSR-D budget: ~60 K€. NCSR “DEMOKRITOS” is the Grant Holder (GH) of the Action, and Dr. T. Triantis participates as a Management Committee (MC) member, Grant Holder Scientific Representative and Grant Holder Manager of the Action.