New EU project to improve protection of the marine environment

Eutrophication, overfishing and habitat loss. The status off the North sea continues to be poor. To reverse this trend, marine ecosystems must be restored and more of the sea protected.

The European Parliament recently adopted a restoration law that calls for more marine habitats to be mapped and plans to restore them. And the EU's biodiversity strategy calls for 30 per cent of European seas to be protected by 2030, with a third of them under strict protection.

"Current protected areas have not been very effective. In many places, fishing and other activities are allowed. The new legislation will provide better and more effective protection for marine habitats," says Pierre De Wit, researcher in marine biology at the Department of Biological and Environmental Sciences at the University of Gothenburg.

Eelgrass meadows and mussel beds

The newly launched EU project MARHAB will take a broader view of what needs to be done to improve the protection of the marine environment. The project, led by the Norwegian Institute of Marine Research, will bring together researchers from five different countries focusing on the marine habitats in the Kattegat and Skagerrak seas. The results will then be used in the implementation of new protected areas.

"We will develop guidelines and methods to ensure that the measures implemented have a better effect," says Pierre De Wit.

An important part of the project is to examine how the distribution of individuals within species should be taken into account when planning new protected areas. Pierre De Wit, together with his colleague Marlene Jahnke from the Department of Marine Sciences, will particularly focus on mussel beds and eelgrass meadows, two habitats that are important for many marine species.

"It is important that the protected areas form a network between which individuals can disperse. For this to work, we need to take into account, for example, ocean currents, genetic variation and the different dispersal patterns of species," he says.
 

Lack of large predatory fish

While eutrophication and oxygen depletion have received a great deal of scientific attention – and have been a central focus of management efforts for several decades – the lack of large predatory fish in coastal marine ecosystems has not received the same focus.

Karin Hårding, researcher in zoological ecology at the Department of Biological and Environmental Sciences, together with Norwegian colleagues, will investigate the consequences of fewer large predatory fish and marine mammals in the ecosystems.

"The loss of large predatory fish such as cod can cause so-called trophic cascades, where the absence of predatory fish disrupts ecosystem function and leads to habitat degradation. Studies have shown that when predatory fish disappear, similar effects to eutrophication occur," she says.

Together with her Norwegian colleagues, Karin Hårding will attach transmitters to cod, tuna and seals to map where large predatory fish and marine mammals feed and how they move between different sea areas. This will be an important piece of the puzzle to protect the right areas.

"An important objective of the project is to develop protection that will allow these top predators to return to the west coast of Sweden. For this to happen, there must also be corridors between the protected areas so that the large predatory fish can move without being fished out," she says.

Text: Karl-Johan Nylén