van Leeuwen et al. 
Maritime and Fisheries Fund. Deltares and IFREMER were partly 
supported by the Jerico-S3 project, funded by the European Union’s 
Horizon 2020 research and innovation programme under grant 
agreement No 871153. RBINS received financial support from 
BELSPO through the project ReCAP, which is part of the Belgian 
research program FED-tWIN. 
Acknowledgments 
We like to thank Thomas Neumann (IOW) and Stiig Markager 
‚Aarhus University) for their contribution to derive pre-eutrophic 
Joundary condition for the Baltic Sea outflow. A very special thanks 
:©o Hjalte Parmer for providing the ICES data that are used within 
ıhe COMPEAT tool. We thank the members of ICG-Eut and TG- 
COMP for the fruitful discussions, as well as OSPAR for 
commissioning this work. Part of the maps in this manuscript 
were made using the free package M_Map: Pawlowicz, R., 2020. 
“M_Map: A mapping package for MATLAB”, version 1.4m, 
[Computer software], available online at www.eoas.ubc.ca/-rich/ 
map.html. Computing facilities for Deltares were provided by the 
DECI resource Cartesius based in The Netherlands at SURFsara 
with support from PRACE. The support of Maxime Moge from 
SURFsara, The Netherlands is gratefully acknowledged. UK riverine 
data was processed from raw data provided by the Environment 
Agency, the Scottish Environment Protection Agency, the Rivers 
Agency (Northern Ireland) and the National River Flow Archive. 
French water quality data was provided by Agence de l’eau Loire- 
Bretagne, Agence de l’eau Seine-Normandie and IFREMER, while 
low data was provided by Banque Hydro. German and Dutch 
riverine data was provided by the University of Hamburg (Johannes 
Paetsch, Hermann Lenhart), with some additional German river 
data supplied by IOW (Ulf Graewe). Irish flow data was provided by 
Hydrodata and the Environment Protection Agency (Hydronet), 
while water quality data was obtained from OSPAR RID reports. 
Norwegian flow data was supplied by NVE’s Anne Fleig (afl@ 
10.3389/fmars.2023.1129951 
nve.no), water quality data was obtained from NIVA (www.niva.no) 
and Tore Hegäsen (tore.hogaasen@niva.no). Danish water quality 
data was provided by the National Environmental Research 
Institute (NERI). Water quality data for Baltic rivers was 
provided by the University of Stockholm and the Baltic Nest 
(www.balticnest.org/bed). Spanish data was provided by Dr. Luz 
Garcia (while at Cefas, UK). Portuguese data was obtained from Dr. 
Amelia Araujo (Cefas, UK). Dr. S. M. van Leeuwen, NIOZ, 
Lansdiep 4, ‘t Horntje, Texel, the Netherlands, pers. comm. 
Conflict of interest 
The authors declare that the research was conducted in the 
absence of any commercial or financial relationships that could be 
construed as a potential conflict of interest. 
The reviewer JB declared a shared affıliation Helmholtz Centre 
for Materials and Coastal Research with the author CS to the 
handling editor. 
7ublisher’s note 
All claims expressed in this article are solely those of the authors 
and do not necessarily represent those of their affiliated 
organizations, or those of the publisher, the editors and the 
teviewers. Any product that may be evaluated in this article, or 
claim that may be made by its manufacturer, is not guaranteed or 
endorsed by the publisher. 
Supplementary maz:eria! 
The Supplementary Material for this article can be found online 
at: https://www.frontiersin.org/articles/10.3389/fmars.2023.1129951/ 
‚ull#supplementary-material 
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