Shipping traffic through marine protected areas in the Baltic Sea and the North Sea/Skagerrak–Kattegat region is far more extensive than one might expect. A new report from the Swedish Institute for the Marine Environment shows, for example, that more than 20,000 vessel passages occur in just three of the areas that the EU has classified as among Europe’s most valuable for conservation. This is despite the fact that there is considerable legal scope for introducing stricter regulations.

Sweden and the EU support the UN target of protecting 30 percent of the world’s oceans. According to the EU Biodiversity Strategy, at least 10 percent of marine areas should moreover be strictly protected. Along the Swedish coast and in Swedish territorial waters, marine protected areas have therefore been established—primarily in the form of nature reserves and national parks, but also as part of Natura 2000, the network of Europe’s most valuable natural areas.

A new report from the Swedish Institute for the Marine Environment, commissioned by the Swedish Agency for Marine and Water Management (HaV), analyzed historical AIS data from vessels and shows that around 9,390 unique ships with registered IMO numbers operated in the Baltic Sea and the North Sea during 2023. Tankers, dry bulk carriers, and general cargo vessels accounted for nearly 70 percent of traffic, while ferries, RoRo vessels, container ships, and cruise ships made up an additional roughly 11 percent. Smaller vessels, fishing boats, and leisure craft without IMO numbers were not included in the analysis. Just under three percent of the ships sailed under the Swedish flag.

What is particularly striking is the sheer volume of traffic passing through marine Natura 2000 sites. In nine out of eleven areas, thousands of vessel passages were recorded annually, and in three of them the figure exceeded 20,000. In several cases, shipping lanes guided traffic straight through protected areas via existing traffic separation schemes.

This raises concerns about impacts on marine ecosystems. Previous research shows that shipping can cause significant damage through discharges of oil, chemicals, and scrubber water, as well as through underwater noise. For critically endangered species such as the Baltic harbour porpoise and the long-tailed duck, several of these areas are crucial for reproduction and overwintering.

At the same time, the report finds that the legal room for manoeuvre is greater than is currently being used. Its legal analysis shows that EU Natura 2000 rules, in combination with international maritime law, give coastal states the ability to introduce more far-reaching restrictions on shipping, particularly within territorial waters. Examples from Germany, Italy, Greece, and Norway demonstrate that environmentally adapted routes and restrictions are already feasible.

The report also highlights the need for international measures. Reforming the Baltic Sea’s designation as a Particularly Sensitive Sea Area (PSSA), as well as banning discharges of scrubber water, are identified as important steps. If the conservation objectives of Natura 2000 areas are to be taken seriously, the analysis concludes, both national and international regulations must be fully utilized, and the environmental impact of shipping can no longer be treated as an exception in protected marine areas.

The report was authored by researchers from the University of Gothenburg, the Swedish Maritime University at Linnaeus University, and Uppsala University. Kjell Larsson analyzed the extent of shipping traffic based on AIS data from the Swedish Maritime Administration. David Langlet and Niels Krabbe analyzed the legal conditions for achieving reduced environmental impact.