Beyond PhD-projects

DC1: Sedimentary Phosphate Remobilisation and In-Stream Mitigation Under Climate Change

Project Focus

This project investigates how climate change conditions transform aquatic sediments into internal pollution sources and develops nature-based solutions using readily available materials to trap phosphorus and emerging contaminants.

Research Approach

The research combines laboratory experiments and field studies to examine phosphorus and pollutant remobilization from sediments under various environmental conditions including warming, intermittent flow, and changing oxygen levels. Different adsorptive materials such as iron-rich filter sand, activated charcoal, and woodchips will be tested in both artificial channels and experimental catchments.

Key Objectives

Determine remobilization potential of sediments under climate change scenarios
Test and optimize materials for in-situ pollutant trapping
Develop temperature-dependent models for phosphorus mobilization and adsorption
Create management strategies for mitigating water pollution in future climate conditions
Expected Impact
The project will provide water agencies and industry with crucial information about climate-induced pollutant remobilization risks and identify climate-resilient materials for effective in-stream remediation measures in highly polluted waters.

Host Institution: WasserCluster Lunz, Austria
Supervisor: Gabriele Weigelhofer (WCL/BOKU Vienna)
International Collaboration: Institut Agro (France), SLU (Sweden)

Project Focus
This project develops innovative fingerprinting techniques to trace colloidal phosphorus and associated elements in European river networks, advancing our understanding of hidden pollution pathways that are typically overlooked in water quality assessments.

Research Approach
The research employs advanced field flow fractionation and particle size separation techniques to identify and quantify particle-specific nutrients in soils and waters. Focus is on nanoparticles (<25 nm) rich in organic carbon and fine colloids (25-400 nm) composed of Fe/Al-oxides that are crucial for phosphorus mobilization and retention. Stable isotope approaches will be used to trace nitrogen mobilization patterns.

Key Objectives

• Quantify colloidal nutrient mobilization and retention processes across catchments
• Identify hot spots and hot moments of colloidal phosphorus emissions
• Develop colloidal fingerprinting tools for tracking nitrogen mobilization
• Predict phosphorus emissions during extreme hydrological events (droughts, floods)

Expected Impact
The project will improve quantification of overall nutrient losses in European rivers, enabling better targeting of catchment remediation efforts and future-proofing of water quality management strategies under global change scenarios.

Host Institution: Forschungszentrum Jülich (FZJ), Germany
Supervisor: Roland Bol (FZJ), Michael Rode (UFZ), Gabriele Weigelhofer (BOKU)
International Collaboration: Uppsala University (Sweden), James Hutton Institute (UK), POSTNOVA, AFBI, CHIVAS

Project Focus
This project harnesses long-term, sub-hourly water quality data from diverse European catchments to decode the complex relationships between hydrological patterns and pollution dynamics, moving beyond traditional low-frequency monitoring approaches.

Research Approach
The research analyzes concentration-discharge (c-q) relationships using high-frequency sensor data to understand how pollutants behave during different flow conditions and extreme events. Advanced pattern recognition techniques will identify dominant biogeochemical processes, while simple measurements like turbidity, conductivity, and UV-absorbance will be validated as cost-effective proxies for tracking multiple pollutants simultaneously.

Key Objectives

• Analyze high-frequency water quality patterns across diverse catchments and climatic conditions
• Link temporal pollution patterns to dominant hydrological and biogeochemical processes
• Develop and validate low-cost proxy measurements for multi-pollutant monitoring
• Create a catchment-specific catalogue of c-q behaviors for different pollutants

Expected Impact
The project will provide water managers with practical tools to maximize value from existing monitoring networks, enable real-time pollution tracking using affordable sensors, and improve understanding of how individual storm events integrate into long-term water quality patterns.

Host Institution: Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
Supervisor: Magdalena Bieroza (SLU), Susana Bernal (CEAB-CSIC), Phil Jordan (Ulster)
International Collaboration: Ulster University, INRAE (France), INTEL, Irish EPA, LUODE Consulting

Project Focus

This project examines how phosphorus (P) and nitrogen (N) are retained, transformed, and removed within European stream networks. By integrating biogeochemical and hydrological perspectives, the research aims to improve understanding of nutrient processing in both anthropogenically impacted streams and streams with near-natural morphology.

Research Approach

The project combines high-frequency in-stream sensor data with stable P and N isotope techniques to quantify nutrient uptake, retention, and removal across spatial and temporal scales. Field studies will focus on headwater streams with contrasting hydro-morphological characteristics, while network-scale analyses will assess cumulative in-stream nutrient processing. The approach allows disentangling assimilatory uptake, sediment sorption, and hydrological controls on nutrient dynamics.

Key Objectives

• Quantify seasonal variability in nutrient retention in headwater streams with differing hydro-morphology using stable isotope approaches

• Assess assimilatory nutrient uptake, in-stream removal, and sorption to stream sediments using high-frequency measurements

• Analyse nutrient removal and processing at the river-network scale

Expected Impact

The project will advance mechanistic understanding of nutrient retention in stream networks and provide robust, process-based evidence to support river-management strategies aimed at reducing diffuse nutrient pollution. Results will be directly relevant for water authorities and environmental agencies working to improve water quality under varying land-use and hydrological conditions.

Host Institution: Helmholtz Centre for Environmental Research – UFZ, Department of Aquatic Ecosystem Analysis, Magdeburg, Germany
Supervisors: Michael Rode (UFZ, Germany); Roland Bol (FZJ, Germany); Zahra Thomas (IARA, France)
International Collaboration: Uppsala University (Sweden); James Hutton Institute (UK); Institut Agro (France); TRIOS and LHW (Germany)

Project Focus

This project explores how citizen science (CS) can be effectively engaged to support water quality monitoring and aquatic ecosystem protection. The research focuses on understanding the social, technical, and organisational dimensions of citizen science and how CS initiatives can complement conventional monitoring frameworks at local and catchment scales.

Research Approach

The project applies an interdisciplinary approach combining social science methods, data-quality assessment, and environmental monitoring frameworks. It will compare motivations, roles, and perceptions among different stakeholder groups involved in water improvement activities, including local communities, NGOs, and agencies, both with and without citizen science involvement. Existing and newly generated CS datasets will be analysed to assess reliability, quality control, and their potential contribution to formal water assessment and management.

Key Objectives

• Investigate who participates in citizen science and their motivations, comparing community groups, NGOs, and other stakeholders

• Evaluate the reliability and quality of citizen science data for water quality monitoring and assessment

• Identify monitoring and knowledge gaps that can be addressed through citizen science

• Develop a citizen science–based toolkit for identifying pressures at local and catchment scales

• Evaluate existing and emerging frameworks for establishing and sustaining long-term citizen science initiatives

Expected Impact

The project will provide evidence-based guidance on how citizen science can be integrated into water quality monitoring and protection strategies. Outcomes will support environmental agencies, researchers, and community organisations in designing robust, inclusive, and sustainable citizen science programmes that enhance monitoring coverage, stakeholder engagement, and catchment-scale water governance.

Host Institution: University College Dublin, School of Biology & Environmental Science, Dublin, Ireland
Supervisors: Mary Kelly-Quinn (University College Dublin); Jan-Robert Baars (University College Dublin); co-supervised by Gabriele Weigelhofer (WasserCluster Lunz, Austria)
Advisors: Per-Erik Mellander (Teagasc, Ireland); Alena Bartosova (SMHI, Sweden); Eulyn Pagaling (James Hutton Institute, UK)

Project Focus

This project investigates why improvements in chemical water quality do not always translate into improved ecological status in European river networks. Focusing on agricultural headwater catchments, the research examines how multiple stressors—including nutrients, sediment, and hydrological variability—interact to affect aquatic ecosystems.

Research Approach

The project adopts an integrated experimental design combining field observations, controlled mesocosm experiments, and laboratory studies. It explicitly addresses the contrasting effects of acute versus chronic pollutant inputs under varying flow conditions and a changing climate. By linking chemical pressures to biological responses, the research aims to unravel mechanistic pathways driving ecological degradation.

Key Objectives

• Assess the impacts of acute and chronic inputs of multiple pollutants (including phosphorus, nitrogen, and sediment) and flow variability on aquatic bio-indicators

• Establish the mechanisms through which nitrate affects aquatic communities

• Define ecological impact thresholds for nitrate and sediment under multiple-stressor conditions

Expected Impact

The project will provide critical insights into the causes of mismatches between chemical and ecological status assessments under European water policy frameworks. Results will support more ecologically meaningful nutrient and sediment management strategies in agricultural catchments and inform future monitoring and regulatory approaches under climate change.

Host Institution: Teagasc, Environment, Soils and Land Use Department, Wexford, Ireland
Supervisors: Daire Ó hUallacháin (Teagasc, Ireland); Per-Erik Mellander (Teagasc, Ireland); Mary Kelly-Quinn (University College Dublin, Ireland); Marcin Penk (University College Dublin, Ireland)
International Collaboration: James Hutton Institute (UK); Sveriges lantbruksuniversitet (Sweden); WasserCluster Lunz (Austria)

Project Focus

This project investigates how low-flow conditions and flow intermittency influence stream metabolism, water chemistry, and the capacity of fluvial networks to process carbon and nutrients. With increasing water scarcity under climate change, the research focuses on intermittent streams as highly vulnerable systems where biogeochemical functioning and water quality are particularly sensitive to hydrological extremes.

Research Approach

The project combines field measurements, laboratory experiments, and hydrochemical modelling to quantify in-stream carbon and nutrient cycling and associated greenhouse gas emissions. Research will assess the spatial and temporal extent of low-flow conditions, variability in stream water chemistry, and changes in bioreactive capacity across contrasting land uses and hydrological regimes. Scenario-based modelling will be used to explore future changes in water quantity and quality under increasing drought and intermittency.

Key Objectives

• Quantify the effects of low flows and intermittency on stream metabolic activity and water chemistry

• Assess in-stream carbon and nutrient processing and associated greenhouse gas emissions under varying hydrological conditions

• Evaluate how land use and hydrological variability influence bioreactive capacity in intermittent stream networks

• Use hydrochemical models to explore future water quantity and quality scenarios under water scarcity

Expected Impact

The project will improve understanding of how intermittent fluvial networks function under hydrological stress and provide a scientific basis for adapting monitoring strategies to low-flow conditions. Results will support water managers and policymakers in developing evidence-based recommendations to protect water quality and ecosystem functioning in increasingly drought-prone river systems.

Host Institution: Center of Advanced Studies of Blanes (CEAB-CSIC), Blanes, Spain
Supervisors: Susana Bernal (CEAB-CSIC, Spain); co-supervised by Per-Erik Mellander (Teagasc, Ireland) and Ophélie Fovet (INRAE, France)
International Collaboration: Institut Agro (Agrocampus Ouest Rennes, France); Teagasc (Ireland); and other BEYOND partner institutions

Project Focus

This project investigates how nutrient export dynamics—including long-term trends, seasonal variability, and storm-driven responses—change across spatial scales, from small headwater catchments to meso-scale river basins. A central aim is to understand how hydro-climatic extremes such as droughts, heatwaves, and extreme precipitation events differentially affect water quality depending on catchment size and stream order.

Research Approach

The research integrates high-resolution water quality monitoring from long-term research catchments across multiple European countries with analyses of public water surveillance datasets at the EU scale. In addition, targeted field monitoring will be implemented downstream of a well-instrumented headwater catchment to track how water-chemistry signals propagate through the river network. Statistical spatio-temporal analyses and parsimonious modelling approaches will be used to disentangle land-to-water delivery signals from in-stream processing and point-source influences.

Key Objectives

• Quantify how nutrient export dynamics vary across spatial scales from headwater to meso-scale catchments

• Assess how hydro-climatic extremes influence water quality as a function of catchment size and stream order

• Test the relative importance of land-to-water delivery versus in-stream processes along the river continuum

• Analyse how nutrient signals observed in headwaters propagate downstream under current monitoring designs

Expected Impact

The project will provide new insights into scale-dependent controls on nutrient export under climate variability and change. Outcomes will inform the design of more effective monitoring strategies and improve interpretation of water quality data across river networks, supporting science-based nutrient management and climate adaptation strategies at catchment to European scales.

Host Institution: INRAE, Joint Research Unit SAS, Rennes, France
Supervisors: Rémi Dupas (INRAE, France); Ophélie Fovet (INRAE, France)
Co-supervisors: Magdalena Bieroza (Swedish University of Agricultural Sciences); Per-Erik Mellander (Teagasc, Ireland)
Advisors: Miriam Glendell (James Hutton Institute); Michael Rode (Helmholtz Centre for Environmental Research – UFZ)

Project Focus

This project examines whether agro-ecological agricultural systems can be scaled to protect water quality while delivering multiple ecosystem services under future climate and socio-economic change. While agroecology promotes whole-system management with reduced external inputs, its catchment-scale impacts on water quality remain insufficiently quantified. The research addresses this gap by evaluating systemic agronomic change and targeted spatial interventions.

Research Approach

The project applies a systems-based modelling framework integrating hydrology, water quality, soil science, and agronomy across climatic gradients. Scenario analyses will assess how agro-ecological practices influence diffuse pollution (nutrients, sediments, and other contaminants), ecosystem services, and resilience to hydrological extremes. Modelling will be complemented by limited field data collection and engagement with farming stakeholders to ensure relevance and realism.

Key Objectives

• Assess the potential of agro-ecological practices to mitigate diffuse pollution and deliver multiple ecosystem services (clean water, carbon stewardship, biodiversity)

• Evaluate how systemic changes in agronomic practice affect water quality and water resources under future hydrological extremes

• Quantify the scale and spatial targeting of interventions required for mitigation and adaptation across contrasting climatic conditions

Expected Impact

The project will provide evidence on how agro-ecological transitions can contribute to water quality protection, climate resilience, and co-delivery of ecosystem services at catchment to regional scales. Outcomes will support policymakers, water managers, and the farming sector in designing effective, climate-robust agri-environment strategies.

Host Institution: James Hutton Institute, Environmental and Biochemical Sciences Department, Aberdeen, Scotland
Supervisors: Miriam Glendell (James Hutton Institute); Cathy Hawes (James Hutton Institute); Phil Jordan (University of Ulster)
Additional Support: Nicholas Schurch (Biomathematics and Statistics Scotland); Leah-Jackson Blake (Norwegian Institute for Water Research); Per-Erik Mellander (Teagasc)
International Collaboration: Agricultural Research Programme (Ireland); Biomathematics and Statistics Scotland; Norwegian Institute for Water Research (NIVA); CARBERY food producer (Ireland)

Project Focus

This project investigates how pollutant stressors and climate change influence microbially mediated nutrient cycling in river networks. By focusing on ecosystem-scale processes, the research aims to improve understanding of how changes in microbial communities affect carbon (C), nitrogen (N), and phosphorus (P) cycling and the delivery of key aquatic ecosystem services.

Research Approach

The project combines field-based ecosystem measurements with microbial community analysis across gradients of land use, climate, riparian conditions, and water chemistry. Experimental approaches will assess how chemical and physical stressors alter microbial community composition and function, linking microbial responses to in-stream nutrient cycling and ecosystem services. Particular attention will be given to whether specific functional microbial groups provide more sensitive or informative indicators of stress than whole-community diversity.

Key Objectives

• Characterise changes in microbial community composition across environmental pressure gradients linked to chemical and physical stressors

• Quantify how pollutants affect microbial community structure and in-stream C, N, and P cycling

• Assess whether specific microbial functional groups differ in stressor sensitivity compared with whole-community diversity

• Evaluate the potential of microbial indicators to inform improved river monitoring and management strategies

Expected Impact

The project will advance mechanistic understanding of how pollutant pressures and climate change affect microbial regulation of nutrient cycling in rivers. Results will support the development of process-based and biologically meaningful indicators for water quality assessment, contributing to more effective river management and protection strategies.

Host Institution: James Hutton Institute, Environmental and Biochemical Sciences Department, Aberdeen, Scotland
Supervisors: Eulyn Pagaling; Marc Stutter; Phil Jordan; Anna Lupon
Institutional Collaboration: Ulster University, School of Geography and Environmental Sciences
International Collaboration: University College Dublin; Centre d’Estudis Avançats de Blanes; Scottish Environment Protection Agency; Environment Protection Agency; CHIVAS