“Mitigation of cyanobacteria in lakes by dilute hydrogen peroxide”- Dr Petra Visser at NCSR Demokritos

Dr Petra Visser is giving a lecture on “Mitigation of cyanobacteria in lakes by dilute hydrogen peroxide” in the Library Hall of NCSR Demokritos, on 21st March 2019 at 13:00.

Dr Petra Visser is Associate Professor in the Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam. Her research interests include physiology and ecology of cyanobacteria and algae, toxic cyanobacteria, eutrophication, water management, macroalgae, benthic cyanobacterial mats, coral reefs. She has carried out pioneering work on the use of hydrogen peroxide for selective suppression of harmful cyanobacteria in entire lakes. Among others, she has been Leader of the Working Group “Prevention and Control of Toxic Cyanobacteria and Cyanotoxins” of the CYANOCOST network and Editor of a recent Special Issue on “Cyanobacterial blooms – Ecology, prevention, mitigation and control” in Aquatic Ecology.

Description of the event


The European multi-lake survey dataset is published in Scientific Data.

The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. The first product of the European Multi Lake Survey (EMLS) was published by Mantzouki et al. (2018) in Toxins. Following this publication, the dataset of in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, is now published in Scientific Data (Mantzouki et al. 2018). The data can be found and downloaded from the Environmental Data Portal (EDI). EMLS was coordinated by Evi Manzouki and Bas Ibelings from the University of Geneva, and supported by COST Actions Netlake and CYANOCOST.


  1. E. Mantzouki et al. (2018). A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins. Scientific Data 5, 180226. https://doi.org/10.1038/sdata.2018.226 .
  2. Data citation: Mantzouki, E. et al. (2018). Environmental Data Initiative https://doi.org/10.6073/pasta/dabc352040fa58284f78883fa9debe37

The Principle and Value of the European Multi Lake Survey

Abstract from a recent paper by E. Mantzouki & B. Ibelings, published in  Limnology & Oceanography Bulletin  (ASLO):

On‐going global warming and eutrophication are expected to promote cyanobacterial dominance worldwide. Although increased lake temperature and nutrients are well‐established drivers of blooms, the mechanisms that determine cyanobacterial biomass are complex, with potentially direct, indirect, and interactive effects. Cyanobacteria can produce toxins that constitute a considerable risk for animal and human health and thus a substantial economic cost if we are to ensure safe drinking water. Such global range phenomena should be studied at a wide spatial scale, to directly compare phytoplankton response in different lake types across contrasting climatic zones. The European Multi Lake Survey (EMLS) sought to harness the power of group science in order to sample lakes across Europe and disentangle the effect of environmental stressors on potentially toxic cyanobacterial blooms. The first EMLS results showed that the distribution of cyanobacterial toxins and the toxic potential in lakes will be highly dependent on direct and indirect effects of temperature. If nutrients are not regulated, then they may interact synergistically with increased lake temperatures to promote cyanobacterial growth more than that of other phytoplankton taxa. Providing continental scale evidence is highly significant for the development of robust models that could predict cyanobacterial or algal response to environmental change.


Mantzouki, E. and Ibelings, B. W. (2018), The Principle and Value of the European Multi Lake Survey. Limnology and Oceanography Bulletin. . doi:10.1002/lob.10259

First European Multi-Lake Survey on cyanotoxins published !

Article by Evanthia Mantzouki and Bas Ibelings, Univ. of Geneva.

The first product of the European Multi Lake Survey (EMLS) is published in Toxins. This paper would not have been possible without the EMLS, the grassroots initiative that brought together around 200 scientists from 26 European countries to sample their lakes and answer questions of ecological importance. Understanding global scale phenomena, such as climate warming, requires information of high spatial resolution to investigate if lakes of similar characteristics (e.g. morphometry, trophic status) would respond in a consistent manner to similar environmental forcing. Cyanobacterial occurrence as a typical consequence of environmental perturbation in aquatic systems worldwide, was the centre of attention in the EMLS. Starting from a common goal to produce adequate evidence and eventually push for stricter regulation towards improved freshwater quality, the EMLS consortium (Figure 1) designed straightforward sampling protocols to accommodate the capacity in funding, time, personnel and equipment of all participants, without compromising quality. Cyanotoxins, phytoplankton pigments and environmental parameters were sampled and analysed in a fully standardised way to ensure scientific validity.

As a result of this effort, the first peer-reviewed EMLS article casts light on cyanotoxins and toxin quota distribution across the European continent. In an unexpected -but welcoming for our research purpose!- hot summer in 2015, temperature effects, both directly through boosting physiological processes of cyanobacterial growth and, indirectly through enhancing water stability that facilitate buoyant cyanobacterial cells, determined the spatial distribution of hepatotoxins (microcystins), neurotoxins (anatoxin-a) and cytotoxins cylindrospermopsin). The Northern European lakes were struck by a prolonged heat wave, more than the Mediterranean ones, during the sampling period that pinpointed the reality of climate warming. In such an event, toxin diversity increased along the latitudinal gradient, showing that cyanobacterial toxin production is enhanced not necessarily when it is hot (Mediterranean) but when it gets warmer than usual (heat event in North). Increases in toxin diversity (increase in toxin numbers but also representation of each toxin), entailed an increased presence of cylindrospermopsin, anatoxin and less studied microcystin variants, with a simultaneous decrease in the famous MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.

Reference (Open access):

Mantzouki et al. (2018). Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins. Toxins 2018, 10(4), 156; https://doi.org/10.3390/toxins10040156

EMLS was supported by COST Actions NETLAKE and CYANOCOST.


Position as a researcher in marine and coastal lagoon ecology – Sardinia, Italy

The deadline for applications for the position as a researcher in marine and coastal lagoon ecology has been extended to 31 January 2018.

One post-graduate researcher position is available at the Foundation IMC International Marine Centre in Oristano, Sardinia, Italy (http://www.fondazioneimc.it/) in the field of sustainable management and conservation of Mediterranean coastal marine and lagoon environments.

We are seeking for a researcher with expertise in ecology of marine organisms and transitional aquatic environments. In particular, the successful candidate will have to evaluate the interactions between ecological processes and human activities in Mediterranean coastal-marine and lagoon environments assessing environmental quality of marine and transitional areas.


The successful applicant will be expected to:

  • assess the impacts of fishing and aquaculture activities on marine and coastal lagoon environments;
  • monitor and characterize benthic assemblages and fish communities in coastal marine and lagoon environment;
  • assess biotic and abiotic factors affecting benthic assemblages.

The position’s description and application form can be found here.

Postdoctoral researcher in Limnology specialized in lake modelling in Sweden

Project:  WATexR  a Climate JPI project led by Dr Rafa Marce (ICRA, Gerona, ES)

The Department of Limnology at Uppsala University, Sweden is searching for a Post Doctoral researcher specializing in lake modeling.  The post doc will participate in three projects. Common to all projects is the use mathematical models to predict lake hydrothermal structure and lake water quality.

A full description of the position and application instructions are available at. https://uu.mynetworkglobal.com/en/what:job/jobID:178441/. The deadline for the application is 31 December 2017.

This post was sent by Eleanor Jennings, Chair of NETLAKE.