Improved predictions possible for blue-green algae

Published: 20 May 2014

There are more factors involved in the growth of blue-green algae than previously thought: the acidity of the water also has an important role to play. This emerged from the study ‘Physical aspects explaining cyanobacteria scum formation in natural water systems’, Evelyn Aparicio Medrano's doctorate thesis for Eindhoven Technical University, which contributes to an improvement in our understanding of how this 'pond scum' behaves and makes it possible to predict blooms more precisely.

Acccurate forecasting important for bathers

That is important news for water management agencies, for whom cyanobacteria blooms are a major problem, particularly now as the weather is warming up. Miguel Dionisio Pires, Evelyn Aparicio Medrano’s supervisor and also a specialist in cyanobacteria at Deltares: ‘These algae can be particularly toxic and they are a threat to bathers so water managers keep a close eye on cyanobacteria levels by monitoring chlorophyll and cell concentrations in the water, as well as toxins when concentrations rise. However, they still can’t predict levels a few days ahead. That requires information about water temperatures and weather forecasts. Even so, in practice, this has not always produced reliable results and now we know why. Water managers also need to include acidity in their predictions.’

Algal bloom in the Abcoude Lake

Algal bloom in the Abcoude Lake

Major step towards more effective pesticides

The new information will not lead immediately to more effective pesticides. Miguel Dionisio Pires: ‘This is an important first step in that direction. Aeration systems are widely used to prevent algal blooms. They produce fast results but algae start growing again quickly as soon as the system is turned off. The new findings will allow us to look at whether the system can be adjusted differently to have a structural impact.’

For the full text of the thesis: klick here