Royal Netherlands Institute for Sea Research
Phone number
+31 (0)222 36 9423
Senior Research Assistant
  • European riverine nutrient loads
  • Numerical modelling of hydrodynamics and biogeochemistry of marine environment
  • Linking lower to higher trophic level models (end-to-end modelling)
  • Stressor response studies of the marine ecosystem using numerical modelling
  • Ecohydrodynamic regions

Dr. Ir. Sonja van Leeuwen

Senior Research Assistant


Studying marine interactions, stressors and scenarios with complex models


Research interests

As a marine ecosystem modeller my research interests span everything from European riverine nutrient loads, hydrodynamics, marine chemistry, lower trophic levels, higher trophic levels all the way to ecosystem services. I have worked at CEFAS, Lowestoft, UK (a governmental research institute) for 12 years looking at eutrophication, low oxygen zones, deep chlorophyll maxima, ecohydrodynamic regions and combined stressor effects (nutrient loads, climate change, acidification, fishing pressure) in combined lower and higher trophic level models, mainly with a focus on the European Shelf but occasionally further away (Barents Sea, Patagonia, Mediterranean). Though simulations of the marine environment rarely capture the variability observed in nature they do provide information at spatial and temporal scales that observations cannot match, and allow for future and past projection over long time scales (decades to centuries). The latter provides insights into long-term combined stressor response and possible management actions. I have a particular interest in understanding marine biogeochemical processes (including benthic-pelagic coupling), combining bottom-up and top-down pressures in system response and end-to-end modelling.

Although I work mainly with so-called hydrobiogeochemical models, especially GETM-ERSEM-BFM (the joint NIOZ/CEFAS model), I also have experience with size-structured models (representing higher trophic levels, i.e. fish, marine mammals), particle tracking models, the Phytoplankton Index (formerly known as the Phytoplankton Community Index or PCI), linking of lower and higher trophic level models (including 2-way coupling), end-to-end modelling and Fe cycling. I am also the official keeper of the OSPAR ICG-EMO (Intersessional Correspondence Group on Eutrophication MOdelling) riverine load database, consisting of daily flow and nutrient load values for rivers exiting onto the European Shelf. This database is freely available upon request.





Previous key-publications

Van Leeuwen, S.M., le Quesne, W., Parker, E.R. Potential future fisheries yields in shelf waters: a model study of the effects of climate change and ocean acidification, Biogeosciences, 13, p.441-454, 2016 doi: 10.5194/bg-13-441-2016

Van Leeuwen, S.M., Tett, P., Mills, D.K., van der Molen, J. Stratified areas in the North Sea: long-term variability and biological and policy implications, Journal of Geophysical Research - Oceans, Vol. 120 (7), pp 4670-4686, 2015, doi: 10.1002/2014JC010485

Jickells, T., Andrews, J., Barnard, S., Tett, P., van Leeuwen, S.M. Natural Sciences Modelling in Coastal and Shelf Seas, in Coastal Zones Ecosystem Services, K. Turner and M. Schaafsma (eds.), in series Studies in Ecolological Economics, 9, Springer International Publishing Switzerland, 2015, ISBN 978-3-319-17214-9, doi:10.1007/978-3-319-17214-9

Van Leeuwen, S.M., van der Molen, J., Ruardij, P., Fernand, L., Jickells, T. Modelling the contribution of Deep Chlorophyll Maxima to annual primary production in the North Sea, Biogeochemistry, Vol. 113 (1), pp 137—152, 2013, DOI: 10.007/s10533-012-9704-5

Lenhart, H-J., Mills, D.K., Baretta-Bekker, H., van Leeuwen, S.M., van der Molen, J., Baretta, J.W., Blaas, M., Desmit, X.,  Kühn, W.,  Los, H.J.,  Ménesguen, A.,  Neves, R., Proctor, R.,  Ruardij, P.,  Skogen, M.D., Vanhoutte-Brunier, A., Villars, M.T., Wakelin, S. Predicting the consequences of nutrient reduction on the eutrophication status of the North Sea, Journal of Marine Systems, Vol 81,pp 148-170, 2010

Publications since starting at NIOZ

Capuzzo, E., Lynam, C.P., Barry, J., Stephens, D., Forster, R.M., Greenwood, N., McQuatters-Gollop, A., Silva, T., van Leeuwen, S.M., Engelhard, G. H., 2017, A decline in primary production in the North Sea over twenty‐five years, associated with reductions in zooplankton abundance and fish stock recruitment, Global Change Biology, DOI: 10.1111/gcb.13916


Professional education



Awards and Prizes




Linked news

Thursday 15 February 2024
Salt gradient in the Wadden Sea under pressure due to changing climate
Particularly in spring, less and less freshwater flows from Dutch and German rivers into the Wadden Sea. “This affects the life of algae and, therefore, fish and birds on the mudflats as well”, says Professor Katja Philippart, director of the Wadden…
Monday 03 July 2023
Warmest June ever recorded in Wadden Sea; concerns for mortality in overheated cockles
In the past six summers, there were as many as five with high mortality among cockles in the Wadden Sea. That mortality always occurred several weeks after above-average water temperatures were recorded. "I therefore hold my breath for the shellfish,…
Friday 30 June 2023
Dossier: warm sea and ocean water
Global warming dominates global news. Here, rising atmospheric temperatures are usually the common thread. But of all the extra heat trapped by our greenhouse gas emissions, only 1 per cent remains in the air. The vast majority (89 per cent)…

NIOZ publications

  • 2023
    van Leeuwen, S.M.; Lenhart, H.-J.; Prins, T.C.; Blauw, A.N.; Desmit, X.; Fernand, L.; Friedland, R.; Kerimoglu, O.; Lacroix, G.; van der Linden, A.; Lefebvre, A.; van der Molen, J.; Plus, M.; Ruvalcaba Baroni, I.; Silva, T.H.; Stegert, C.; Troost, T.A.; Vilmin, L. (2023). Deriving pre-eutrophic conditions from an ensemble model approach for the North-West European seas. Front. Mar. Sci. 10: 1129951.
  • 2022
    van Leeuwen, S.M.; Beecham, J.; García-García, L.M.; Thorpe, R. (2022). The Mediterranean Rhodes Gyre: modelled impacts of climate change, acidification and fishing. Mar. Ecol. Prog. Ser. 690: 31-50.
  • 2021
    de Winter, N.J.; Dämmer, L.K.; Falkenroth, M.; Reichart, G.-J.; Moretti, S.; Martínez-Garcia, A.; Höche, N.; Schöne, B.R.; Rodiouchkina, K.; Goderis, S.; Vanhaecke, F.; van Leeuwen, S.M.; Ziegler, M. (2021). Multi-isotopic and trace element evidence against different formation pathways for oyster microstructures. Geochim. Cosmochim. Acta 308: 326-352.
    Hjøllo, S.S.; van Leeuwen, S.M.; Maar, M. (2021). Marine research and management topics addressed by process-based ecosystem models. Mar. Ecol. Prog. Ser. 680: 1-6.
    Lenhart, H.; Blauw, A.; Desmit, X.; Fernand, L.; Friedland, R.; Heyden, B.; Kerimoglu, O.; Lacroix, G.; Van der Linden, J.; van der Molen, J.; Plus, M.; Prins, T.; Ruvalcaba, J.L.; Stegert, C.; Thewes, D.; Troost, T.; Vilmin, L.M.; van Leeuwen, S. (2022). ICG-EMO report on model comparison for historical scenarios as basis to derive new threshold values. ICG: [s.l.].
    Skogen, M.; Ji, R.; Akimova, A.; Daewel, U.; Hansen, C.; Hjøllo, S.S.; van Leeuwen, S.M.; Maar, M.; Macias, D.; Mousing, E.A.; Almroth-Rosell, E.; Sailley, S.F.; Spence, M.A.; Troost, T.A.; van de Wolfshaar, K. (2021). Disclosing the truth: Are models better than observations? Mar. Ecol. Prog. Ser. 680: 7-13.
    van der Molen, J.; van Leeuwen, S.M.; Govers, L.L.; van der Heide, T.; Olff, H. (2021). Potential micro-plastics dispersal and accumulation in the North Sea, with application to the MSC Zoe incident. Front. Mar. Sci. 8: 607203.
    van Leeuwen, S.M.; Salgado, H.; Bailey, J.L.; Beecham, J.; Iriarte, J.L.; García-García, L.; Thorpe, R. (2021). Climate change, marine resources and a small Chilean community: making the connections. Mar. Ecol. Prog. Ser. 680: 223-246.
  • 2020
    Jacobs, P.; Kromkamp, J.C.; van Leeuwen, S.; Philippart, C.J.M. (2020). Planktonic primary production in the western Dutch Wadden Sea. Mar. Ecol. Prog. Ser. 639: 53-71.
  • 2019
    Greenwood, N.; Devlin, M.; Best, M.; Fronkova, L.; Graves, C.A.; Milligan, A.; Barry, J.; van Leeuwen, S.M. (2019). Utilizing eutrophication assessment directives from transitional to marine systems in the Thames estuary and Liverpool Bay, UK. Front. Mar. Sci. 6: 24.
  • 2018
    Préat, N.; De Troch, M.; van Leeuwen, S.; Taelman, S.E.; De Meester, S.; Allais, F.; Dewulf, J. (2018). Development of potential yield loss indicators to assess the effect of seaweed farming on fish landings. Algal Research 35: 194-205.

Linked projects

Anieke van Leeuwen
Project duration
1 Jan 2020 - 31 Dec 2024