From pressure indicators to management action: prioritising recreational pressures in freshwater ecosystems under uncertainty

Recreational use of freshwater ecosystems is increasing worldwide, generating diverse pressures that are often poorly quantified and unevenly regulated. Although policy frameworks require the identification of such pressures, translating assessments into prioritised management actions remains challenging, particularly under conditions of data scarcity and multiple co-occurring activities and impacts. This study presents an integrated workflow to support the management of recreational pressures in freshwater ecosystems. The framework combines spatial indicators, stakeholder interviews, expert judgement, and multi-criteria prioritisation to assess pressures from multiple recreational activities and to evaluate management measures. Pressure assessments explicitly distinguish between low pressure and unquantified use, thereby accounting for data gaps rather than masking uncertainty. Management measures are ranked based on expected effectiveness and implementation feasibility, and a decision-support algorithm guides the selection of appropriate responses for individual water bodies, considering data availability, pressure intensity, conservation status, and ecological impact significance. Application of the framework reveals strong spatial heterogeneity in recreational pressures and highlights monitoring deficits, particularly for informal activities that do not require permission. Results indicate that targeted data acquisition of the number of visitors and biodiversity and water quality monitoring often represent the most appropriate initial approach in freshwater ecosystems. More proactive interventions are justified where high pressures coincide with conservation designations and documented ecological impacts. The proposed workflow offers a transparent and adaptable framework to support ecosystem-based management and resource allocation in data-limited and rapidly changing freshwater ecosystem contexts.