The colours of algae lead the way to smarter aquaculture

Signals of toxicity with bright colours, it is called aposematism – nature’s own warning system. Now, researchers at SLU and KTH want to find out whether similar signals also exist below the surface, in algal species that produce toxins in the coastal waters of the Baltic Sea.

The project, called The Kingdom of Colours, focuses on developing and testing new technology to achieve a system for early warning when algae start producing toxins. The researchers will study, among other things, the colours and patterns of the algae. The aim is to create new tools for environmental monitoring and risk management in aquaculture

– The colours of cyanobacteria sometimes reveal more than one might think, and certain colours can indicate the presence of toxic producing bacterias. However, when it comes to macroalgae, knowledge is still limited. One species we are investigating in the project is Ceramium tenuicorne – a filamentous red alga that develops stronger contrasts when producing toxins, almost like a red-and-white warning pattern, says Elin Dahlgren, Associate Professor of Aquatic Ecology and project leader of The Kingdom of Colors at SLU.

To measure the algae’s visual signals, the researchers are developing a specially adapted underwater robot equipped with a multispectral camera and sensors. The robot navigates autonomously and analyzes data in real time using artificial intelligence.

– Our vision is to create an intelligent monitoring system that can detect and interpret subtle visual signals and  changes in algae in real time. It’s like giving the robot biological vision, says Ivan Stenius, Associate Professor at the Royal Institute of Technology and responsible for the robotics development within the project

– Our goal is for our results to be useful for researchers, producers, and decision-makers. We want to provide the aquaculture industry with tools to act in time when the environment changes, says Elin Dahlgren.

The project will run until 2028 and is expected to contribute to sustainability in aquaculture by improving the monitoring of algal toxins and developing technology that can protect both the environment and the economy of the aquaculture industry. The project is funded by the Swedish Board of Agriculture through the EU’s Maritime, Fisheries and Aquaculture Fund.