New policy brief: Safeguard ecosystem function and carbon storage capacity in deep soft bottoms
Deep soft bottoms are of vital importance for the functioning of the whole marine ecosystem and for long-term carbon storage. This is emphasised by researchers from several different departments at Stockholm University in a new policy brief. They stress that EU Member States must be better at protecting these habitats in the Baltic and North Sea.
Hardly anyone has seen them, the muddy sea beds that lie at depths with permanent darkness. They constitute a large part of the Baltic and North Sea ecosystems but are not considered particularly valuable by humans. Nowadays, a large proportion are labelled dead, with bacteria as the only sign of life. But these dark habitats should still be recognised for providing important ecosystem services.
Ellen Bruno, a policy analyst at Stockholm University Baltic Sea Centre, noted a knowledge gap when she listened to people talking in different contexts.
"As a society we talk a lot about the impact of bottom trawling and sea bed mining on deep soft bottoms, but the understanding of which processes and animals we hurt is actually very limited. We wanted to shed some light on the importance of these often unknown, and in my view unappreciated, ecosystems."
Ellen gathered a group of scientists from Stockholm University with relevant expertise, but from very different perspectives. Together they started the work of compiling the relevant knowledge. The resulting policy brief explains the role of benthic ecosystems for marine life and the role of deep soft sediment in the carbon cycle. It also describes the impacts of bottom trawling and seabed mining on marine life, as well as on carbon storage and climate gas release. Legal experts also compiled information on the current legal protection of deep soft bottoms.
But making this policy brief proved more difficult than the group first thought. Because of their location, much of the knowledge of these bottoms comes from extrapolations and models rather than true measurements. Also, investigations of human disturbance is hampered by the fact that there are hardly any bottoms left that are not already disturbed. All in all this renders a lot of uncertainties.
"But when it comes to conclusions and recommendations the researchers were very aligned – these areas are super important and worth a better protection", Ellen Bruno concludes.
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About this policy brief
This policy brief was published by Stockholm University Baltic Sea Centre in April 2025.
The researchers involved were Anna Christiernsson, Department of Law, Volker Brüchert, Department of Geological Sciences, Clare Bradshaw and Francisco Nascimento, Department of Ecology, Environment and Plant Sciences and Sofia Wikström from Baltic Sea Centre.
Last updated: April 10, 2025
Source: Baltic Sea Centre