Nitrogen and phosphorus load reduction approach within safe ecological boundaries for the Nordic-Baltic region

Project Information

NORDBALT-ECOSAFE

Grant agreement ID: 101060020

DOI

10.3030/101060020

Project closed

EC signature date 11 May 2022

Start date 1 September 2022

End date 31 August 2025

Funded under

• Food, Bioeconomy Natural Resources, Agriculture and Environment

Total cost

€ 1 999 008,75

EU contribution

€ 1 999 007,00

Coordinated by

AARHUS UNIVERSITET
Denmark

Periodic Reporting for period 2 - NORDBALT-ECOSAFE (Nitrogen and phosphorus load reduction approach within safe ecological boundaries for the Nordic-Baltic region)

Reporting period: 2024-03-01 to 2025-08-31

Summary of the context and overall objectives of the project

The NORDBALT-ECOSAFE project involved eight partners in the Nordic-Baltic region and included seven work packages and a crosscutting issue on climate change. The project has developed new standards for setting safe ecological boundaries in water bodies and novel
nutrient regulations using sensors, models, mitigation and policy tools and governance schemes. The project has also performed an in-depth assessment of nutrient reference conditions and established harmonized safe ecological boundaries for various biological indicators in several different water body types in the Nordic-Baltic region, including and assessment of climate change impacts on safe ecological quality nutrient thresholds. The project has calibrated and validated a state-of-the-art catchment model (SWAT+) to the project’s six river basins and demonstrated to stakeholders how to estimate nutrient concentrations, loads, sources and pathways. The SWAT+ results has been compared with existing national models to assess model credibility. The water body status after adoption of the new ecological boundaries was then investigated using the SWAT+ model output and discussed with regional stakeholders. The project has produced a guidance and a cleaning software for managers when they use high frequency sensors in nutrient monitoring as well as a scientific analysis of the pros and cons when compared to standard grab sampling monitoring techniques. Furthermore, the project has conducted an analysis of trends in river stoichiometry (N,P,Si) and the outcome was compared with that of historical policies for a larger river dataset from the Nordic-Baltic Region as a demonstration of the use of stoichiometry in water quality monitoring and management. The project has developed a policy brief on balancing GHG emissions with nutrient loadings to water bodies as a new framework for novel nature-based solutions (NBSs) and mitigation measures (MMs), including guidance for optimum efficiency for nutrient reduction and side effects. Finally, a River Basin Management Support System for implementing NBSs and MMs in river basins to meet nutrient reduction targets has been developed and demonstrated in the pilot river basin Odense, Denmark. Two rounds of regional meetings with stakeholders and policy makers was held during the project period.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

NORDBALT-ECOSAFE project has applied a harmonized method to calculate nutrient reference conditions in different freshwater bodies (lakes and rivers) in the Nordic-Baltic region and compared the achieved nutrient reference conditions with the existing nationally applied reference conditions. NORDBALT-ECOSAFE has also developed new boundaries for good/moderate conditions for total N and total P concentrations for a range of river and lake types in the Nordic-Baltic region (Thrane et al., 2025).

The project has delivered seven policy briefs and a joint policy brief with two sister projects NAPSEA and NEW-HARMONICA.

A novel software (SENTEM-QC) for cleaning of high-frequency sensor data has also been developed as part of the project and made public through ZENODO platform (van't Veen et al., 2025). A supporting guidance for the best practices in sensor monitoring has been developed (Rozemeijer et al., 2025) and Monte-Carlo tests of the advantages of using high-frequency sensor technology for river monitoring of nitrogen, suspended sediment and phosphorus has been conducted (van't Veen et al., 2025; Skarbøvik et al., 2025).

The project has tested a new method to apply stoichiometry for nitrogen (N), phosphorus (P) and silicium (Si) in riverine waters for evaluation of the eutrophication potential in marine waters on a large river monitoring dataset from the Nordic-Baltic Region (Futter et al, 2025).

Calibration and validation of the SWAT+ model on six river basins in the Nordic-Baltic region has been conducted and the six SWAT+ setups made available through a depository.

NORDBALT-ECOSAFE has developed a classification framework considering various factors that are essential for selecting, designing, and evaluating a particular measure has been developed in NORDBALT-ECOSAFE. In combination with the SWAT+ modelling in WP4, the classification framework can help to identify the most suitable measures and optimize their placement in a given river basin/catchment. NORDBALT-ECOSAFE has also developed examples of Info Sheets that enables end-users to compare between the six NORDBALT-ECOSAFE countries established knowledge on NBSs and MMs.

A novel model support system for running scenarios with SWAT+ has been developed 'CatchmanSS'. A test of the novel model support system has been run on river Odense Basin (Bieger et al., 2025).

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

NORDBALT-ECOSAFE has developed and tested a new method to derive nutrient reference conditions for river and lake types in the NORDIC-BALTIC region as the methodology has been tested in the six partner countries.

NORDBALT-ECOSAFE has developed a Fact Sheet with new safe nutrients boundaries for establishing good ecological conditions in different river and lake types in the NORDIC-BALTIC region (Thrane et al., 2025).

NORDBALT-ECOSAFE has developed a novel software technology for cleaning of high-frequency sensor data (SENTEM-QC) that is available for download on ZENODO (SentemQC – software. 10.5281/zenodo.13830623) and a paper describing the software was publised in Open Research Europe (van’t Veen et al., 2025: (https://doi.org/10.12688/openreseurope.18134.2)).

NORDBALT-ECOSAFE has investigate the advantages of implementing high-frequency sensors for nutrient monitoring (van't Veen et al., 2025 & Skarbøvik et al. 2025).

NORDBALT-ECOSAFE has developed a support tool for running scenarios with SWAT+ (CatchManSS)

NORDBALT-ECOSAFE has tested stoichiometry for N. P and Si on a larger river monitoring dataset from the Nordic-Baltic region (Futter et al., 2025).

NORDBALT-ECOSAFE has calibrated, validated and run scenarios on how to close the gap between current nutrient levels and the boundary nutrient levels to achieve good ecological status in rivers, lakes and coastal waters in six Nordic and Baltic river basins (Bieger et al., 2025).

Project River Basins and Monitoring Netwrok Stations

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