Madrid, 5 (Europe Press)
These are the conclusions of scientists from the Helmholtz-Zentrum Hereon, related to the North Sea and published in the journal Communications Earth & Environment.
Varying conditions and wind currents, increasing precipitation and changing surface climate: the impacts of offshore wind farms in the North Sea are diverse and not yet fully investigated. Some are already happening, and others are still expected due to the continued expansion of wind turbines into large-scale wind farms. To better understand it and fill in the remaining knowledge gaps, a team of researchers from the Hereon Institute for Modeling and Analysis of Coastal Systems is working on different key elements of the problem.
For example, Nils Christiansen’s team showed that wake turbulence (vortices of air caused by wind turbines) alter the flow and stratification of the water beneath. But the climate directly above sea level is constantly changing, as another team led by Dr. Naveed Akhtar has been able to show.
The latest study, led by Dr Otti Dowell, confirms that these effects also alter the spatial distribution of components of the marine ecosystem. This includes the distribution of nutrients, phytoplankton and zooplankton, as well as biomass in the sediment, which is the food base for many bottom-dwelling organisms.
In the model study, the team hypothesized the existence of large-scale offshore wind farms in the North Sea. For deep marine areas, the researchers found that the amount of vital carbon in the sediment would increase locally by 10% and that the oxygen concentration, in an area that was already very low, could drop even further.
In addition, already proven wind changes would locally modify primary phytoplankton production by up to +/- 10%. And this is not only in the regions of the wind farms themselves, but also distributed throughout the southern North Sea. This means that even if the total production in the region changes slightly, there is a spatial redistribution of production. This also has consequences for the distribution of zooplankton, which is the food base for many species of fish. The early life stages of fish in particular often depend on the availability of zooplankton “at the right time, in the right place”.
The spatio-temporal restructuring of zooplankton distribution can influence these process chains and thus positively or negatively affect the amount of available fish. Therefore, even a small change in primary production will have a lasting impact on the entire food web in the southern North Sea.
“Our results show that significant expansion of offshore wind farms will have a significant impact on the structuring of offshore coastal ecosystems. We need to quickly better understand these impacts and also take them into account in managing coastal ecosystems,” concludes Otti Doyle in a statement.
“Award-winning zombie scholar. Music practitioner. Food expert. Troublemaker.”