Stockholm Royal Seaport

Sustainability Report

A marine park is planned for Stockholm Royal Seaport

Stockholm Royal Seaport borders Husarviken in the north and Lilla Värtan in the east, and features eight kilometers of waterfront. In the upcoming detailed development plan for Kolkajen, a marine park is planned, designed to enhance recreational values and aquatic biodiversity.

When Kolkajen, located in the northeast of Stockholm Royal Seaport, is fully developed, it will include 1,250 residences, spaces for services and businesses, and numerous public areas. Kolkajen is surrounded by the waters of Lilla Värtan, and the planning work has focused on making the waterfront location accessible. Therefore, the marine park is now being planned with docks and pathways, aimed at enhancing the habitat for aquatic life.

"The marine park will be a water-themed park environment, designed for marine life with aquatic plants and reeds that create a varied habitat for fish and other aquatic creatures. The park will strengthen the conditions for aquatic life in Lilla Värtan," says Staffan Lorentz, Head of development for Stockholm Royal Seaport, Stockholm City Development Administration.

New habitats for fish and plants

Although Stockholm is a city on the water, there are currently few natural spawning and breeding grounds for fish left in the inner city. Boat harbours and hardened quays occupy the sheltered bays and shallow shores that fish require. Therefore, the ambition is for the Marine Park to mimic a natural bay, with zones of varying depths to offer different environments for fish and plants to inhabit. The zones vary in depth from 0.5 meters to 3 meters, contributing to varying temperatures and different bottom materials. Shallow areas also include protected breeding grounds built with stone blocks.

Beneath the piers, reefs will connect Husarviken with the Marine Park. The plan is for the reefs to consist of net bags filled with blasted rock, known as gabions. The reefs’ cavities and aquatic plants provide nooks and nourishment for both small and large fish. The Marine Park will provide conditions for many organisms to establish themselves or visit temporarily. Shore plants such as reed and eelgrass will be planted as part of the project, but the idea is that several aquatic plants and algae will establish themselves over time. The same applies to fish species like perch, roach, bream, pike, and trout. Besides fish and plants, the marine park will also offer favourable habitats for many bird species.

"Through the design, the ambition is to spark a curiosity for marine life and the idea is for the park to be used as an educational tool for nature and environmental issues. The Marine Park is also part of the research project MASSA, which investigates how excavation materials from the expansion of Stockholm's metro can be used to create new habitats in Stockholm's inner archipelago. The park will develop over time, but we have observed that reefs have been constructed with positive results in several locations," says David Langseth, project manager at the Development Administration.

"The Marine Park will contribute to more sustainable fish stocks, recreational activities such as sport fishing, and the opportunity to see spawning pike right in the city. Creating a new environment for aquatic biodiversity, although relatively small, contributes to significant educational value, highlighting the importance of favourable habitats and urban nature. Our hope is that this will create ripples for future projects within the city. The Marine Park, along with the new fish wetland at Lillsjöäng and the forthcoming reef in Isbladsviken, will contribute to the marine ecology around the whole of Lilla Värtan,” says Oliver Karlöf, fish biologist at the Sports Administration.

Collaboration in early stages

The work on the Marine Park is conducted in close collaboration with several of the city’s administrations. Working with aquatic biodiversity at such an early stage is relatively unusual within the City of Stockholm. By addressing these issues early, biology and ecology become a natural part of how the area is built and developed, rather than compensating for this at a later stage.

The Marine Park will be lined with piers, outdoor cafés, trees, and plantings. Across the bay, there will be several smaller pedestrian bridges, which will be closed during parts of the spring to avoid disturbing the spawning fish. The Marine Park can be constructed once the area has been remediated and as the final part of the transformation occurring through block development adjacent to Kolkajen, and is expected to be completed during 2037.

More information

For more information about the marine park, please contact David Langseth.

Article Published: 21/04/2024 Updated: 05/06/2024