Understanding and managing cyanobacterial blooms of the future: learning from past and present day dynamics

• Research unit: COST
• Project number: C13.0105

Key words (English)

Eutrophication; climate change; harmful algal blooms; synergistic interaction; paleolimnology; lake survey; chemostat experiments; predictive models

Research programs (English)

COST-Action ES1105 - Cyanobacterial blooms and toxins in water resources: Occurrence, impacts and management

Short description (English)

Eutrophication is still a large problem facing surface waters in Europe. Blooms of cyanobacteria choke out other aquatic life and produce toxins which endangers the safe production of drinking water, recreation and public health. The recent scientific literature forecasts that climate warming will augment these problems. A warmer climate will promote cyanobacterial blooms and threatens to undo decades of succesful lake restoration in Europe,.where meausures to mitigate eutrophication and control cyanobacterial blooms have been taken at the expense of billions of euros. Yet there is no scientific consenus about the way eutrophication and climate change will interact. Some authors claim nutrients will remain the main cause of blooms and see only a minor role for temperature, while others predict climate warming will have a major impact ('blooms like it hot'). Important question: will nutrients and temperature interact synergistically? This is not only of scientific interest, it also determines which measures must be taken to prepare our ecosystems and control blooms in future. This proposal seeks to provide reliable answers on the question how the two stressors interact. We will do so by a three pronged approach: (i) paleolimnology (learning from climate change in the past), (ii) experiments under controlled conditions in chemostats, (iii) a multiple lake survey in all CyanoCOST countries, results to be used to construct a predictive cyanobacterial distribution model.

Further information (English)

Full name of research-institution/enterprise: University of Geneva - Faculty of Sciences Department F.-A. Forel for Environmental and Aquatic Sciences & Institute for Environmental Sciences - Uni Carl Vogt - Room C211

Partners and International Organizations (English)

AT; BE; BG; HR; CY; CZ; DK; EE; FI; FR; F.Y.R. of Macedonia; DE; EL; HU; IE; IL; IT; LT; LU; NL; NO; PL; PT; RO: RS; SK; SI; ES; SE; TR; UK; US

Abstract (English)

Eutrophication is still a large problem facing surface waters in Europe. Blooms of cyanobacteria choke out other aquatic life and produce toxins which endangers the safe production of drinking water, recreation and public health. The recent scientific literature forecasts that climate warming will augment these problems. Yet there is no scientific consenus about the way eutrophication and climate change will interact. Important question: will nutrients and temperature interact synergistically? This is not only of scientific interest, it also determines which measures must be taken to prepare our ecosystems and control blooms in future. We investigate this question using 3 complementary approaches: (i) a European wide multi lake survey across gradients of nutrients and temerature, (ii) paleo-limnology, how did nutrients and temperature interact in the past to stimulate blooms?, (iii) multi-factoral design experiments. In 2015 a special issue of Aquatic Ecology was assembled – with our participation as guest-editors and co-author of several papers - in which all available methods to mitigate and control cyanobacterial blooms and restore lake ecosystems were presented and discussed. Most papers are now online, the formal publication of the whole issue will follow in September 2016. Also in 2015 a Eurpean scale multiple lake survey (EMLS) in all CyanoCOST countries was carried out. Representative from ca 30 different countries were invited to a Training School (TS) in Evian-les-Bains (F) where every aspect of the lake sampling, sample processing, storage and shipment was discussed and practiced. Participants of the TS went home to their respective countries as ambassadors of the EMLS to stimulate participation. Some 400 lakes have been sampled. All samples were shipped to Wageningen (NL). Dedicated labs were identified for the analysis of all samples to ensure comparability: flowcytometry of phytoplankton was carried out in Geneva, algal pigments using HPC in Amsterdam, nutrients and cyanobacterial toxins in Wageningen. Each country will do microscopy of their own lakes using standardises methods. Samples for eDNA have been taken and stored. Work on papleolimnology and experiments was continued but less intensively than the EMLS, which was the centre of activity in 2015. Data analysis and interpretation will follow in 2016.

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C13.0105