DESTRESS

Context

Growing human demand for clean freshwater and accelerating climate change are putting increasing pressure on river ecosystems worldwide. Human freshwater consumption mainly involves the abstraction of groundwater or surface water for drinking and irrigation of agricultural land. Increasing urbanisation further disrupts the cycle through centralised discharges of wastewater and urban runoff. This combination of climate change-induced extreme weather events, human freshwater consumption, and urbanisation leads to a significant increase of flow extremes in river systems (droughts and floods) that threatens riverine biodiversity as well as freshwater supply for human society and food safety. In order to identify the quantitative limits of sustainable freshwater use (i.e. the Safe Operating Space (SOS)), the minimum flow requirements of riverine biodiversity need to be quantified.

Main objectives

The overall objective of DESTRESS is to provide guidance and actionable knowledge needed to balance freshwater needs between riverine biodiversity and human society. This project will enable a faster and more informed transition towards biodiversity-positive management and policies in river catchments with multiple functions and potentially conflicting interests.

Main activities

DESTRESS is spearheaded by the Aquatic Synthesis Research Centre (AquaSYNC) and will synthesise and analyse unique and comprehensive time series of European riverine macroinvertebrate monitoring data to identify temporal trends in ecological and biological trait composition, abundance, and common biodiversity metrics (based on >2,000 sites across 23 European countries; 1968-2020, average 15 years of sampling). Temporal biodiversity trends will be linked to simulated hydrological regimes for a subset of the sites and to existing European data on measured contaminant exposure to analyse pressure-response relationships and identify biodiversity change points along existing gradients of hydrological and contaminant stress. The pressure-response relationships will be used to define SOS for riverine biodiversity in the context of their water quality and quantity requirements.

Through co-creation processes with key stakeholders at local, national, and European level, the concept of SOS will be applied to relevant case study examples to understand management, end user, and legislative requirements for the effective development of the SOS concept in these areas. These inputs will be key for the SOS concept development in DESTRESS, ensuring that the final guidance document is operational, relevant, and meets the legislative requirements of end users, managers, and competent authorities across EU member states. The guidance document will enable evidence-based decision- making on freshwater consumption, supply, and treatment to balance water quantity and quality needs between freshwater biodiversity and human society.