The Baltic Sea is suffocating. It has had too much of the good stuff for too long. And I’m not talking about fast food as we know it. I’m talking about people and industries pouring agricultural runoff and sewage into the sea for years. These high nutrient inputs cause overgrowth, a phenomon known as eutrophication. The nutrients work as food for microscopic algae , causing them to increase in numbers. More algae leads to a higher consumption of oxygen. Without oxygen, very few organisms can live. So what should we do about it? The Algoland recovery project is working on one way to decrease nutrient inputs to the Baltic Sea.
In rain or shine, the Algoland sampling crew dons their work gear and heads out in a car filled with sampling bottles to a greenhouse located at a local power plant, Kalmar Energi. There, three “raceway ponds” which, to the casual observer may look like strange algae-filled bathtubs, help the team to do important work in the field of sustainability.
Tiny, unicellular aquatic plants called microalgae are grown in these raceway ponds to treat wastewater that leaks out from the nutrient-heavy landfill nearby (owned by waste management company KSRR). As a bonus, carbon dioxide, a waste product from Kalmar Energi’s heat production, is bubbled into the raceway ponds to boost microalgal growth. By using the natural ability of microalgae to take up nutrients and carbon dioxide, we can help industries to clean their wastewater and their greenhouse gas emissions.
But Swedish climate is not always as nice as in the post cards. In fact, most of the time it’s not. And this of course has implications for growing microalgae. Therefore, we grow microalgae during the different seasons to understand how our climate influences nutrient uptake. So far, we have experienced a winter experiment with snow up to our knees, a spring experiment where we nearly suffered heatstroke, and now finally a rainy autumn experiment is ongoing. The question still remains: Which season is most beneficial for microalgal nutrient recovery, and why?
– by Lina Mattsson
Lina Mattsson is a PhD student of supervisor Dr. Catherine Legrand in the Department of Biology and Environmental Sciences at Linnaeus University. She is a member of the research group Marine Phytoplankton Ecology and Applications and works on the Algoland project.