Climate change could make cyanobacteria more toxic

Certain cyanobacteria in water produce toxic blooms. Changes in the climate could result in more toxic cyanobacteria. But what determines their toxicity? NIOO-researcher Dedmer van de Waal has just won a major European grant to find out. "From tiny cells to the entire ecosystem, we're going to get to the nitty-gritty using novel techniques."

It's a hot summer's day and you could do with a nice, cool dip. But you're out of luck: no swimming allowed, due to harmful algal blooms (HABs). The cyanobacteria that form these blooms - also referred to as blue-green algae - can also contaminate drinking water and harm cattle. For millions of people worldwide, that's not some bleak vision of the future but everyday reality. And climate change could make things so much worse.

"Toxic blooms are becoming more frequent and more intense due to too many nutrients in the environment", says NIOO-researcher and cyanobacteria-expert Dedmer van de Waal. "Climate change will in all likelihood aggravate this problem." Yet we know precious little about the how and why of the toxicity of these ancient organisms in the water.

Toxic success

What we do know is that it involves a combination of factors at different ecological scales: from the accumulation of cyanobacterial biomass in the water to the dominance of toxic species or genotypes, and the amount of toxin in a single cell.

So how do we find out more? With the help of theory, technology and a whole slew of expertiments. "With more knowledge, we can begin to understand how the properties of an algal cell may contribute to the success of a toxic species", clarifies Van de Waal.

Technology in this case means a tricked out flow cytometer: a device that can test more than 1000 cells per second by running them past a laser beam, allowing for the properties found in naturally occurring algal communities to be analysed almost live. "In this way, we can take a kind of fingerprint of properties, and develop an understanding of why particular species are dominant."

Natural labs

To measure the reponses of the many different cyanobacteria species and genotypes, Van de Waal is to use a new version of the so-called 'lab on a chip'.  "It's no bigger than a stamp, but still it has 64 mini test chambers." He's developing the chip together with Twente University. In due course, Van de Waal will be able to perform the ultimate tests in both the limnotron facilities (indoor experimental lakes) of NIOO's labs and the natural outdoor lab of Dutch lakes.

"It won't just tell us how climate change affects toxic algal blooms, it will also give us a new toolbox of knowledge and techniques for water management. With it, we can hopefully monitor water quality more thoroughly on points that are found to stimulate toxic algae."

Tackling big questions

Last Thursday, the European Research Council announced the latest round of its Consolidator Grants, awarding funding to research projects in 24 countries to "tackle big scientific questions." Van de Waal's BLOOMTOX was among nearly thirty Dutch projects to win a substantial (2 million euro) grant.

Out of a total of 2652 applications from mid-career scientists, 313 were successful. That's 12%. The grants should help them pioneer breakthroughs on important scientific and social issues. As ERC president Prof. Maria Leptin commented: "We do not know today how their work might revolutionise tomorrow - we do know that they will open up new horizons, satisfy our curiosity and most likely help us prepare for unpredictable future challenges."

Project Dedmer van de Waal: 

• BLOOMTOX - Global change impacts on cyanobacterial bloom toxicity

More information:

• Researcher Dr. Dedmer van de Waal, Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), +31-317-473553 / +31-6-14126667, d.vandewaal@nioo.knaw.nl
• Science information officer Froukje Rienks, Netherlands Institute of Ecology (NIOO-KNAW), tel. +31-6-10487481 / +31-317-473590, f.rienks@nioo.knaw.nl