AWS Postdoc Projects

Amsterdam Water Science startup activities: investing in three new postdoc projects.

The contribution of atmospheric CO2 to phytoplankton productivity in eutrophic lakes

Dr. Jolanda Verspagen

Many freshwaters receive large amounts of terrestrial derived organic matter. The mineralization of this organic matter causes CO2 supersaturation. Lakes are therefore generally considered to be sources of CO2 to the atmosphere. Phytoplankton need inorganic carbon for photosynthesis and growth and can consume large quantities of CO2. The productivity of many freshwaters is largely subsidized by the mineralization of organic matter. However, in eutrophic systems with dense phytoplankton blooms, the contribution of atmospheric CO2 to phytoplankton productivity may be substantial, and these lakes may be sinks of CO2 at least during summer. Dense blooms in eutrophic systems often largely consist of toxic cyanobacteria that are hazardous to public healthand rising CO2 concentrations are predicted to intensify these blooms.

To be able to assess to what extent rising atmospheric CO2 concentrations will impact phytoplankton bloom size, we first need to quantify the current contributions of atmospheric CO2 and organic matter to phytoplankton productivity in eutrophic lakes. In this project we will measure CO2 fluxes from the atmosphere and the sediment and measure primary productivity in a shallow Dutch peat lake. A mathematical model will be built to make more accurate predictions on the impact of rising CO concentrations of phytoplankton bloom intensity.


Visser, P. M., Verspagen, J. M. H., Sandrini, G., Stal, L. J., Matthijs, H. C. P., Davis, T. W., Paerl, H. W., & Huisman, J. (2016). How rising CO2 and global warming may stimulate harmful cyanobacterial blooms. Harmful Algae, 54, 145-159.

Sandrini, G., Ji, X., Verspagen, J. M. H., Tann, R. P., Slot, P. C., Luimstra, V. M., Schuurmans J. M., Matthijs H. C. P., & Huisman, J. (2016). Rapid adaptation of harmful cyanobacteria to rising CO2. Proceedings of the National Academy of Sciences, 113, 9315-9320.

Water Science Image Arie Vonk

Jolanda Verspagen preparing a multisensor probe for deployment.

Sediment’s history defines future of constructed reservoirs in river deltas

Dr. J. Arie Vonk

In delta regions, population densities are amongst the highest globally and combined with sea level rise this results damming of water bodies to ensure protection against flooding and availability of freshwater. In the resulting shallow reservoirs, focus has been mainly on the management of water quantity while ecological quality is often low. Since these reservoirs are characterized by unconsolidated sediment and large sediment-surface to water-volume ratios, the benthic-pelagic coupling plays a strong role in ecosystem functioning of these water bodies. Alterations in this coupling, for example induced by development of extensive mono-cultures of macrophytes or by expansions of invasive filterfeeders, will have profound effects on the ecology in these systems.

We hypothesize that in shallow freshwater reservoirs in delta regions, sediment origin and composition together with processes over the sediment-water interface drives element cycles and ecosystem functioning of these systems.

The focus of our study is on:

  • the influence of coupled fluxes of phosphorus, iron and sulphur over de sediment-water interface on the trophic status and functioning of benthic communities
  • sediment resuspension and resulting particle–algae interactions that define aggregation, settlement, and productivity in shallow reservoirs
  • organic matter settlement, decomposition and mineralisation to assess whether sediment is a carbon sink or source for pelagic productivity (collaboration with AWS-project Jolanda Verspagen)


Vonk, J. A. et al. The significance of linoleic acid in food sources for detritivorous benthic invertebrates. Sci. Rep. 6, 35785; doi: 10.1038/srep35785 (2016).

Bridget R. Deemer, John A. Harrison, Siyue Li, Jake J. Beaulieu, Tonya DelSontro, Nathan Barros, José F. Bezerra-Neto, Stephen M. Powers, Marco A. dos Santos and J. Arie Vonk: Greenhouse Gas Emissions from Reservoir Water Surfaces: A New Global Synthesis, BioScience (November 01, 2016)66 (11): 949-964.doi: 10.1093/biosci/biw117

Hunting ER, Vonk JA, Musters CJM, Kraak MHS, Vijver MG (2016) Effects of agricultural practices on organic matter degradation in ditches. Scientific Reports 6: 21474

Bohan DA, Landuyt D, Ma A, Macfadyen S, Martinet V, Massol F, McInerny G, Montoya JM, Mulder C, Pascual U, Pocock MJ, White P, Blanchemanche S, Bonkowski M, Bretagnolle V, Bronmark C, Dicks L, Dumbrell A, Eisenhauer N, Friberg N, Gessner MO, Gill RJ, Gray C, Haughton A, Ibanez S, Jensen J, Jeppesen E, Jokela J, Lacroix G, Lannou C, Lavorel S, Le Galliard JF, Lescourret F, Liu S, Loeuille N, McLaughlin O, Muggleton S, Penuelas J, Petanidou T, Petit S, Pomati F, Raffaelli D, Rasmussen J, Raybould A, Reboud X, Richard G, Scherber C, Scheu S, Sutherland WJ, Tamaddoni-Nezhad A, Ter Braak C, Termansen M, Thompson MS, Tscharntke T, Vacher C, Van der Geest H, Voigt W, Vonk JA, Zhou X, Woodward G (2016) Networking our way to better ecosystem service provision. Trends in Ecology and Evolution 31:105-115

Mulder C, Bennett EM, Bohan DA, Bonkowski M, Carpenter SR, Chalmers R, Cramer W, Durance I, Eisenhauer N, Fontaine C, Haughton AJ, Hettelingh J-P, Hines J, Ibanez S, Jeppesen E, Krumins Adams J, Ma A, Mancinelli G, Massol F, McLaughlin Ó, Naeem S, Pascual U, Peñuelas J, Pettorelli N, Pocock MJO, Raffaelli D, Rasmussen JJ, Rusch GM, Scherber C, Setälä H, Sutherland WJ, Vacher C, Voigt W, Vonk JA, Wood SA, Woodward G (2015) 10 Years later: Revisiting priorities for science and society a decade after the Millennium Ecosystem Assessment. Advances in Ecological Research 53:1-53

Water Science Image Arie Vonk

Arie Vonk holding a sediment sample.

Dr. Joshua F. Dean

Joshua Dean is a postdoctoral researcher at the Vrije Universiteit Amsterdam and will be running a novel eddy-covariance set up with Prof. Han Dolman to measure the carbon dioxide emissions and sequestration in the Amstelveense Poel alongside Jolanda’s measurements. Joshua will also be working with Arie Vonk to develop methods to measure dissolved carbon dioxide and methane in the water across the lake.

AWS_Joshua Dean

Joshua F. Dean working in a peatland in central Scotland

Extreme future weather events

Dr. Iris Manola

The Netherlands is a low lying country shaped by river deltas, that makes it very vulnerable to flooding events. Due to climate change the frequency and intensity of extreme precipitation events is expected to increase. It is therefore of high importance to develop climate change scenarios tailored towards the needs of policy makers in order to develop efficient adaptation and mitigation strategies to reduce the hazard risks from future extreme weather events.
It is mainly not the climate (i.e. the average weather) that concern policy makers, but the extreme weather events causing such flooding. Therefore, a new concept has been introduced recently that takes known historic events as a basis, and modifies the observed data so that the outcome shows how the same event would occur in a warmer climate. This concept is introduced as ‘Future Weather’.
This project presents a novel method of projecting a future extreme precipitation event, based on a historic event (the flooding event of 28 July 2014 over the broader area of Amsterdam). The outcome is compared to a benchmark method using a weather model.


Manola, Iris, Bart van den Hurk, Hans de Moel, and Jeroen Aerts. "Developing future precipitation events from historic events: An Amsterdam case study." In EGU General Assembly Conference Abstracts, vol. 18, p. 459. 2016.

AWS Fieldresearch

Iris Manola launching a weather balloon.

Published by  IBED Water

23 November 2016