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RESEARCH ARTICLE

Monitoring of cyanobacteria for water quality: doing the necessary right or wrong?

M. Moustaka-Gouni A D , U. Sommer B D , M. Katsiapi A and E. Vardaka C
+ Author Affiliations
- Author Affiliations

A Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece.

B GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, Düsternbrooker Weg 20, D-24105 Kiel, Germany.

C Department of Nutritional Sciences and Dietetics, International Hellenic University, GR-574 00 Thessaloniki, Greece.

D Corresponding authors. Email: mmustaka@bio.auth.gr; usommer@ifm-geomar.de

Marine and Freshwater Research 71(5) 717-724 https://doi.org/10.1071/MF18381
Submitted: 30 September 2018  Accepted: 3 September 2019   Published: 27 November 2019

Abstract

Cyanobacteria are an essential biological component of phytoplankton water quality assessment. However, there are some problems associated with the widely used everyday practices of sampling, estimation and use of cyanobacteria when calculating phytoplankton indices assessing water quality. Many indices were developed during the implementation of the Water Framework Directive, considered the most innovative European environmental legislation. Most indices include cyanobacteria as a composition or bloom metric. Problems with the indices concern the exclusion of most chroococcalean taxa from cyanobacterial biovolume estimations in lakes and reservoirs of the Mediterranean region, treatment of the mucilage of colonial chroococcalean taxa in biovolume estimations and overlooking of deep-water cyanobacterial blooms due to sampling depth. These problems may lead to a biased view of water quality. In this paper we argue in favour of including all cyanobacteria taxa and their mucilage in biovolume estimations and considering a sampling depth that covers deep-water maxima, such as those formed by Planktothrix rubescens or colonial chroococcalean taxa.

Additional keywords: Cyanodictyon imperfectum, euphotic zone, Greece, Merismopedia tenuissima, Secchi depth, Water Framework Directive, WFD.


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