Giving Compass' Take:
- New research from the University of Gothenburg shows how trawling restrictions are benefitting anemones and coral in addition to fish and shellfish in the Koster Sea.
- How might similar restrictions be implemented in other marine areas to support the conservation of habitats for marine creatures such as coral and anemones?
- Learn more about key climate justice issues and how you can help.
- Search our Guide to Good for nonprofits focused on climate justice in your area.
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The marine wildlife in Kosterhavet National Park has changed rapidly in recent years. The introduction of trawling restrictions in the area for the national park during the last 25 years, brought about a change in the living conditions for the animals that live on the seabed.
“Animals that capture nutrients through filtration, such as mussels, anemones and soft corals, do not thrive when bottom trawls stir up sediment from the seabed. Several of these species have recovered significantly,” says Matthias Obst, researcher on marine ecosystems at the University of Gothenburg and research leader in the project.
Loss at Shallow Depths Is Remedied by Trawling Restrictions
At the same time, the study shows that large and heat-sensitive species are declining at shallow depths in the Koster Fjord or are disappearing completely from the area. The most dramatic decline has been in the football sponge Geodia barretti, while the excavated fileclam Acesta excavata also declined steadily. Both animals are important components of the Koster Sea ecosystems as they build habitats for many other organisms.
The study was made possible thanks to a large treasure of underwater videos taken at a rock wall in Koster Sea. The wall has been filmed with an underwater robot during various study visits, teaching sessions and projects at the Tjärnö Marine Laboratory from 1997 onwards.
Machine Learning
“The videos were stored on a number of thick hard drives that were kept on a shelf. We are lucky that the underwater photographers at the Tjärnö Marine Laboratory chose to keep this data until now, when we can use machines to go through it,” says Matthias Obst.
Without machine learning, it would have been impossible to analyse such a large number of underwater videos with varying quality and count the abundance of 17 different species over 26 years, 1997–2023. Master's student Christian Nilsson reviewed selected parts of the material and taught an AI object detection model to recognise characteristic features of each species.
Read the full article about trawling restrictions in the Koster Sea at University of Gothenburg.