Tjärnö – Marine Research and Coastal Scenery

Tjärnö is part of an island chain south of Strömstad, connected by bridges. The chain includes Öddö, Tjärnö, and Saltö, farther out. The coastal landscape is characterized by small, narrow cultivated plots in rock crevices; from Tjärnö, the view stretches across Kosterhavet. Marine research, island nature, and traces of local history give a stay here different points of focus.

Marine Research and Insights into Kosterhavet

Tjärnö is home to the University of Gothenburg’s marine research station. As a workplace and knowledge center, it shapes the island. The Tjärnö Marine Laboratory is located in northern Bohuslän, in Sweden’s most species-rich marine area and right next to Kosterhavet National Park. School groups and the general public are welcome there.

At Tjärnö Aquarium, you can see more than 200 different animal and algae species from the underwater world of Kosterhavet, as well as a Swedish coral reef. A touch pool lets you see species such as dead man’s fingers, cushion stars, and sea cucumbers up close. The aquarium is open to the public in summer; two marine biologists answer questions and give live presentations, for example about oysters, lobsters, crabs, or jellyfish. Since the seasonal program may change from year to year, it is a good idea to check the dates before your visit.

On a guided visit to the station, you can hear a marine biologist explain the sea and marine environmental issues. You can also see parts of the research and teaching facilities and the vessels; the visit also includes the aquarium and a film about Kosterhavet National Park.

Excursions and Activities with Seasonal Dates

The 2026 seasonal program described two excursions aboard the research vessel Nereus. On the marine diversity trip, algae and animals are collected from the seabed and then examined at the station under a stereo microscope. The tour “Filming the Depths of Kosterhavet” uses a remotely operated underwater camera to show life 100 meters below the boat; the footage is shown live on board and explained by a guide. Both activities are seasonal. Check the dates for your travel period before you go.

Tjärnölaboratoriet also offers seasonal activities: children can learn more about marine life through stories, their own investigations, and experiments. The program takes place over two mornings, one at the beach and the next in the laboratory. In summer, the laboratory also hosts popular science talks about life in and around the sea. Gullnäsgården on Tjärnö has a different focus, offering courses and retreats on topics such as active relaxation, mindful breathing, self-care, yoga, meditation, and Qi Gong. Specific offerings may change.

Saltö: Trails, Beach, and Underwater Trail

In the nearby Saltö Nature Reserve, easy-to-walk trails wind through pine forest; there are also opportunities for swimming, fishing, and hiking. The landscape includes rolling wooded areas, meadows, and pastures, with granite as the predominant bedrock. Saltö is one of the entrances to Kosterhavet National Park.

A special feature is the underwater snorkel trail, about 200 meters long. It runs at a depth of 1 to 1.5 meters and has eight underwater information signs. If you prefer to stay on land, you can use the forest trails or enjoy the scenery from one of the swimming spots. Svallhagen’s sandy beach is an excursion destination on Tjärnö. At the swimming area by Bofors Camping, the strip of shore is narrow; the seabed consists of sand and small stones. There is a parking lot, toilets, bathing jetties, and a kiosk there in summer.

Church and Local History

The current stone-built Tjärnö Church was constructed in 1855 to plans by architect Carl Gustaf Blom Carlsson. However, written evidence of a stone church in Tjärnö dates back to the Middle Ages; the earliest records are from 1391. The former church and the present building therefore belong to different periods of local history. Summer concerts are held at Tjärnö Church; their program is seasonal.

Bus route 891 connects Strömstad with the aquarium. Route numbers and timetables may change, so check the timetable for your travel date in advance. If you are looking for a hotel for a stay on Tjärnö, the area’s different points of focus can help you decide: marine research and seasonal activities, trails and swimming spots, or the island’s history.

Discover more destinations: Öfverby, Båleröd, Skee, Flåghult, Hällestrand, Strömstad, Hogdal, Svinesund

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