Algae are true all-rounders. They not only improve the water quality, but are also in demand in industry and cosmetics. Therefore, scientists in the Baltic Sea want to combine two useful things. As part of a research project, they are specifically cultivating native bladderwrack on the foundations of wind turbines. There it is supposed to clean the over-fertilized water and could also be harvested as a raw material, for example for cosmetics.
Bladderwrack (Fucus vesiculosus) is one of the best-known brown algae in the North and Baltic Seas. It gets its name from the olive-sized bubbles in its tissue. These gas-filled bubbles give it buoyancy in the water, bringing the algae closer to the sunlight. Bladderwrack is the largest vegetable biomass producer in the Baltic Sea and provides a valuable habitat for many marine organisms. At the same time, this macroalgae is also versatile for us humans. For example, it is used as animal feed, fertilizer and food, but also as an ingredient in cosmetics. It also filters nutrients out of the water and thereby cleans it.
Wind power foundations as an algae breeding station
It is therefore not surprising that research has long since taken a look at the useful brown alga and is looking for efficient ways to benefit from it. The focus of the project “Climate-friendly offshore production of algae biomass” is primarily the improvement of the water quality in the Baltic Sea. Because: “Even if you don’t always look at it everywhere, the Baltic Sea is doing badly,” says Ulf Karsten from the University of Rostock, who is co-coordinating the project. “This is mainly due to the continued excessive introduction of nutrients, which massively deteriorate the water quality.” The brown areas of the Baltic Sea also suffer from this over-fertilization, their stocks have decreased in recent years.
Karsten’s team was therefore looking for a way to grow bladderwrack in the Baltic Sea in the most efficient and sensible way possible. The idea behind this: In order to give the young bladderwrack the necessary support, it could be cultivated on the foundations of offshore wind turbines. A corresponding test facility is to go into operation soon in Eckernförde Bay near Kiel. The team from the University of Rostock, the GEOMAR Helmholtz Center for Ocean Research Kiel and the Christian-Albrechts-University in Kiel are using special raft structures to test whether and how the bladderwrack can be cultivated under conditions similar to those at offshore facilities.
Double benefit
This algae cultivation would not only be useful for the stocks of bladderwrack, its cultivation would also benefit the water quality of the Baltic Sea. As the brown algae grow, they absorb nutrients and thus help to clean the seawater. The seagrass meadows of the Baltic Sea would also benefit from this filtering effect of the bladder wrack, because the heavy nutrient load is currently endangering this important habitat for fish and small animals. Healthy seagrass meadows would have some advantages for the Baltic Sea ecosystem. Because they store large amounts of carbon dioxide, release oxygen into the water and also solidify the sediments on the sea floor.
Algae farming would not only serve to protect the Baltic Sea and its habitats. Since the bladderwrack has to be fished out in good time before it decomposes, these residues could possibly also be used industrially, for example as an ingredient in cosmetics. Karsten can also imagine the brown algae as a substitute for fertilizer in agriculture. “That would stimulate the formation of humus in the soil and increase soil fertility,” explains the marine ecologist. In order to check which possible uses are really possible, the research team will examine the components of bladderwrack in detail.
Source: University of Rostock, GEOMAR Helmholtz Center for Ocean Research Kiel, Christian-Albrechts-University of Kiel