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;

EMLS was supported by COST Actions NETLAKE and CYANOCOST.


Microcystin-LR included in the proposed revision of the Drinking Water Directive !

The European Commission has issued a proposal for a Directive on the Quality of Water Intended for Human Consumption. The proposal is a recast of Directive 98/83/EC, which was amended in 2003, 2009 and 2015.

Microcystin-LR is included in the proposal as a “Chemical Parameter”, with a parametric value of 1μg/L, along with other organic compounds that are added in the list (Bisphenol A, Haloacetic acids, Nonylphenol, PFAS). Performance criteria for determination of MC-LR are specified as 30% uncertainty at the parametric value, while methods should comply to the requirements of ISO 17025.

Inclusion of MC-LR in the proposed Directive is a result of increased occurrence of microcystins in European waters and beyond, as well as of increased awareness of the health risks and hazards associated with toxic cyanobacteria. CYANOCOST has significant contributions in this field, including two books on chemical analysis of cyanotoxins and molecular detection of toxigenic cyanobacteria and many joint parers on cyanotoxin research. Since 2012, CYANOCOST has also contributed in raising awareness of cyanotoxins in Europe; in this sense, the proposed Directive is rewarding of the vast amount of voluntarily work done within the Network and highlights the important societal impact of COST Actions.

The proposed Directive is under public consultation till 2 April 2018. You can download the related documents and submit your feedback here.



Toxic cyanobacteria and cyanotoxins in European waters – A review of CYANOCOST contributions

A review by Meriluoto et al. (Advances in Oceanography and Limnology, 2017; 8(1): 161-178) summarizes the outcomes of some recent European research concerning toxic cyanobacteria and cyanotoxins, with an emphasis on developments within the framework of the CYANOCOST Action. Highlights of the Action include phycological and ecological studies, development of advanced techniques for cyanotoxin analysis, elucidation of cyanotoxin modes of action, management techniques to reduce cyanobacterial mass development, and research on methods and practices for cyanotoxin removal during drinking water treatment. The authors have identified a number of gaps in knowledge. Proposed directions for future research on toxic cyanobacteria and cyanotoxins are also discussed.

The review is open-access and can be downloaded here.

This review is published within the CYANOCOST Special Issue in AIOL that can be downloaded here.