WATR - The Blue-Green Algae early warning system

WATR in use as a blue-green algae early warning system that utilizes cutting-edge technology to monitor water quality and detect harmful algal blooms.

Image showing a lake with a blue-green algae bloom

Blue-green algae (BGA), also known as cyanobacteria, can range in colour from greens, reds, blues, and black. BGA can reduce the carbon, nitrogen and deplete dissolved oxygen when overabundant.

As last summer proved, with increasingly hot summers and onset of climate change, it creates the perfect conditions for blue-green algae to literally bloom. This subsequently had a devastating effect as councils issued warnings about the dangers to human, animal, aquatic and environmental health.

Numerous lakes and water facilities across Europe were closed. Creating a devastating effect on water based leisure activity and fisheries. Not to mention the associated revenue impact and risk of liability.

As well as creating a serious threat to water quality, ecosystem stability, drinking water supplies, and public health through toxin production and the large biomass produced in algal blooms. Too much algae in a stream, river, or lake can kill fish and other species. Some algal species release “biotoxins” that can harm or even kill other organisms.

The late detection of BGA will trigger long-term expensive intervention techniques in order to attempt to rectify the issues. When faster, lower cost and less impactful solutions could have been deployed with early warning through real-time monitoring.

As Peter Drucker stated, “You can’t manage what you don’t measure”.

It is essential to understand your water quality benchmarks during the year to detect issues with Blue-Green Algae at the earliest time.

Blue-Green Algae comes in many forms and different strains, all behave differently dependent on the conditions and environments. Therefore, to effectively measure BGA in real-time it’s important to understand the base lines in your waterways during the year. This will define the benchmarks and enable monitoring alerts as soon as thresholds reach a set point.

The WATR Real-Time BGA monitoring solution directly detects the fluorescence of living algal cells and determines relative algal biomass to trigger alerts and notifications. As well as keeping an ongoing data history of algae levels during the year to build trends and more sophisticated detection.

The following charts show how the fluorescence yield detected from the Chl-a and Phycocyanin channels will change for given concentrations of different algae species.

Detection of an algae bloom can be achieved by triggering on deviations from established baselines of the fluorescence signals. This is a robust strategy, as during the onset of an algae bloom, rates of algae growth can often be very rapid.

An example of this is presented below, which is taken from data at the intake of a water treatment processing plant. Although the levels that are being reported are low, a comparable rise is clearly seen in both Chlorophyll-a and Phycoerythrin channels, with the Phycocyanin signal (notated ‘amber’ within the graph) also rising at a significant rate, but with different characteristics.

In the case above, the baseline can be established over the early part of this dataset (15/08 to 29/08). A threshold can be determined based on 6 SDs (Standard Deviations or Σ). By using this method, the resulting increase in signals that had occurred post 31/08 would trigger an alarm.


  • Real-time water quality and BGA health monitoring
  • Reduce the impact of lake closure
  • Timely intervention to reduce impact costs
  • Reduce the impact on the environment

To find out more about WATR’s BGA solution contact:

Glyn Cotton

Get in touch

WATR has been designed to improve water quality around the world by providing an easy, accurate and a reliable way of monitoring water conditions, if you have any enquiries or questions please get in touch. Send us your specific requirements and we will get back to you as soon as possible.