By Jeannette Bylov, AAU Communication and Public Affairs
Photo: Alvise Vianello, Department of the Build Enviroment

Researchers at Aalborg University’s Department of the Built Environment have discovered elevated levels of microplastics in the Limfjord. Their studies reveal that microplastics are widely present in all surveyed fjord areas, which links the North Sea with the Kattegat and covers over 1,500 square kilometers in Northern Jutland. Notably, the concentration of microplastics on the seabed is approximately 100,000 times greater per volume than in the surrounding water.

"The Limfjord has effectively turned into a landfill for accumulated microplastics, posing a serious pollution risk to both wildlife and human health. It’s crucial that we conduct further research and take action to address these issues," says Jes Vollertsen, a research leader and professor at the Department of the Built Environment.

The presence of microplastics can disrupt entire ecosystems by altering food webs and interfering with the reproduction and growth of marine species, ultimately impacting biodiversity. The researchers estimate that between 4 and 165 tons of microplastics may be distributed across the Limfjord's seabed.

Significant concentrations of microplastics have been identified particularly near Aalborg and at locations where wastewater treatment plants discharge. This pollution could have long-term implications for marine environments and for communities that rely on these waters for food and livelihoods. Consequently, these new findings about the Limfjord are alarming.

"Understanding the scope of microplastic pollution is essential for assessing potential risks to both nature and human health. The insights gained from studying microplastics in the Limfjord are vital for informing our decisions on where to act and how to tackle this pressing issue," adds Jes Vollertsen.

Advanced equipment behind the findings

The researchers at AAU have set out to comprehensively assess pollution levels in the Limfjord. To achieve this, they utilized state-of-the-art analytical techniques that enable them to accurately identify and quantify various types of microplastics.

"Our advanced equipment has allowed us to detect particles smaller than the width of a human hair. This level of precision is essential, as different plastics have distinct chemical compositions that can have varying effects on both the environment and human health," says Jes Vollertsen.

Shellfish on the menu could indicate microplastics in our bodies

The studies, which have been conducted between 2020 and 2024, reveal that microplastic pollution has built up in the sediments of the Limfjord. These sediments, which accumulate on the fjord's bottom, can consist of various materials, including minerals, organic matter, and remnants of marine life. Organisms residing in this environment are at risk of chemical contamination, physical harm, and malnutrition if they consume microplastics.

Humans, too, may encounter microplastics through food, particularly shellfish, as well as through drinking water. This exposure could lead to health issues, the full extent of which researchers have yet to fully determine.

More research needed in the Limfjord

Given the alarming levels of microplastics in the Limfjord, the researchers at AAU emphasize the urgent need for greater attention and action to protect both ecosystems and public health.

"Enhanced monitoring and research are essential for understanding the impacts on the Limfjord's ecosystem and for developing effective management strategies," says Jes Vollertsen.