A type of blue-green algae is adapting to rising CO2 levels, meaning the species is even more resilient to changing climate conditions than previously hypothesised.
A team of microbiologists at the University of Amsterdam has conducted research on the implications caused by cyanobacteria on clean drinking water, swimming safety and freshwater ecosystems.
Aquatic microbiologist and project leader Professor Jef Huisman studied the proliferation of the species in lakes and reservoirs during the summer months by analysing its genetic composition in both the lab and in the field under CO2-rich conditions.
Huisman said: “Before this, the adaptive potential of these harmful cyanobacteria in response to increasing CO2 concentrations had never been studied systematically, even though this can help us predict how algal blooms will develop in future.”
Under both lab and field conditions, cyanobacteria’s genetic make-up altered as it responded to increased CO2 exposure.
Co-author Giovanni Sandrini added: “It’s a textbook example of natural selection. Cyanobacteria absorb CO2 during photosynthesis to produce their biomass, and we observed that the strain best equipped to absorb dissolved CO2 eventually gains the upper hand.
“We discovered that these high-speed strains enjoy a major selective advantage in CO2-rich water. Given the rising atmospheric CO2 values, these strains are poised to thrive.”
Cyanobacteria’s adaptation is causing concern for microbiologists because Microcystis is capable of producing microcystin, a toxin that causes liver damage in birds and mammals. In high concentrations, cyanobacteria are disruptive to freshwater ecosystems, killing fish and aquatic plants.
Swimming areas in the Netherlands are often closed due to toxic blue-green algal blooms.
The study, which was funded by the Netherlands Organisation for Scientific Research and supported by Horizon 2020, has been published in the online journal researchgate.