Kosterhavet National Park

Kosterhavet Overview

Kosterhavet National Park, known as Kosterhavets nationalpark in Swedish, is Sweden’s first marine national park, covering approximately 153 square miles (390 square kilometers).

It is located off the western coast of Sweden, near the border with Norway, in the province of Bohuslän. The park surrounds the Koster Islands and extends into the Skagerrak Sea, encompassing an extensive archipelago, rocky islets, deep fjords, and vibrant underwater ecosystems.

Established in 2009, Kosterhavet is part of a larger marine protected area that connects with Norway’s Ytre Hvaler National Park, forming an internationally significant marine conservation region.

Kosterhavet’s landscape is defined by its rugged coastal beauty, shaped by centuries of glacial movement and the relentless forces of the sea. Above water, the park features rocky shores, windswept islets, and small sandy beaches, interspersed with meadows and coastal heathlands. The Koster Islands, North Koster and South Koster, are the heart of the park, with granite cliffs and rolling hills covered in low-lying vegetation.

The waters surrounding the islands are exceptionally clear, with deep trenches and underwater canyons that reach depths of up to 250 meters (820 feet). These nutrient-rich waters support an astounding diversity of marine life, including over 12,000 species, many of which are found nowhere else in Swedish waters. Seagrass meadows, coral gardens, and kelp forests thrive beneath the surface, providing habitat for a wide range of fish, crustaceans, and mollusks.

Kosterhavet is renowned for its rich marine biodiversity, and visitors may spot harbor seals basking on the rocky shores or swimming gracefully through the waters. The park is also home to the elusive porpoise, which can occasionally be seen surfacing in the distance. Fish such as cod, mackerel, and sea trout are common in the area, along with a remarkable variety of invertebrates, including the Norway lobster and rare cold-water coral species.

Birdwatchers will find plenty to admire, as the park supports a variety of seabirds, including common eiders, cormorants, black guillemots, and Arctic terns. The islands also provide breeding grounds for oystercatchers and gulls, while migratory species pass through during different seasons.

One of the most popular features of Kosterhavet is its pristine and relatively untouched underwater world, attracting snorkelers and scuba divers eager to explore Sweden’s only coral reef and the teeming marine life that inhabits it. The park also offers scenic hiking and cycling trails, particularly on North and South Koster, where well-marked paths lead visitors through forests, coastal meadows, and rocky shorelines.

Kayaking is another favorite activity, allowing for a closer look at the park’s hidden coves and sheltered bays. Boat tours provide an easy way to experience the park from the water, with guided excursions that educate visitors about the unique marine environment. Fishing is permitted in certain areas, following strict regulations to protect the ecosystem.

The conservation efforts in Kosterhavet have been largely successful, with strict protections in place to safeguard the delicate marine environment. Collaboration with Norway’s Ytre Hvaler National Park has created a transboundary marine sanctuary, fostering research and conservation initiatives.

Challenges remain, particularly concerning climate change, invasive species, and human activity, such as overfishing and pollution. However, ongoing efforts to promote sustainable tourism, responsible fishing practices, and habitat restoration have helped maintain the park’s ecological integrity.

Kosterhavet serves as an outstanding example of marine conservation in Sweden, offering both a sanctuary for biodiversity and an immersive experience for visitors eager to connect with the country’s coastal heritage.

Park Map

Kosterhavet National Park Highlights

Wildlife

Birds

Kosterhavet National Park is also a haven for seabirds, attracting a wide variety of species that thrive in its coastal and marine environments. These birds rely on the rich waters of the park for food and nesting grounds.

Black Guillemot
A striking seabird with black plumage and bright red legs, the black guillemot is a strong diver that hunts for fish and crustaceans in the coastal waters.

Common Eider
One of the largest ducks in Europe, the common eider is well-known for its soft down feathers, which have been used for insulation in clothing and bedding.

Eurasian Oystercatcher
Easily recognized by its black-and-white plumage and long, bright orange bill, this bird is often seen along rocky shores searching for shellfish.

Great Cormorant
A skilled fisher, the great cormorant dives deep into the water to catch fish, often perching on rocks with its wings spread wide to dry.

Arctic Tern
Known for its incredible migration from the Arctic to Antarctica and back each year, the Arctic tern is a graceful flier that nests on coastal islands within Kosterhavet.

European Herring Gull
A common yet highly adaptable seabird, the herring gull is an opportunistic feeder that thrives along the coast, often scavenging near fishing boats.

Northern Gannet
A large, striking seabird with a yellowish head and long wings, the northern gannet is a spectacular diver, plunging into the water from great heights to catch fish.

Razorbill
A close relative of the puffin, the razorbill is a sleek black-and-white seabird with a distinctive thick beak, often nesting on cliffs and rocky outcrops.

Little Tern
One of the smallest terns in Europe, this agile bird is known for its sharp diving ability as it catches small fish from the water’s surface.

Puffin
Perhaps the most beloved seabird of Kosterhavet, the puffin is instantly recognizable with its colorful beak and waddling walk. It spends most of its life at sea, coming ashore to breed on rocky islands.

Kosterhavet National Park is a vital sanctuary for marine and seabird species, offering a glimpse into the rich biodiversity of Sweden’s coastal waters.

Kosterhavet National Park, Sweden’s first marine national park, is a stunning coastal area known for its diverse marine life and unique underwater ecosystems. Located along the western coast of Sweden near the Koster Islands, the park is home to an incredible array of marine species, including rare corals, crustaceans, and fish. The rich biodiversity of Kosterhavet makes it a vital habitat for many fascinating species.

Harbor Seal
One of the most iconic species of Kosterhavet, harbor seals can often be seen resting on rocky shores or swimming in the shallow waters. They are social animals, forming colonies along the coast, and are known for their curious nature.

Porbeagle Shark
A relative of the great white shark, the porbeagle shark is a powerful predator found in the deeper waters of the park. It is known for its speed and endurance, feeding on fish and squid.

Norway Lobster (Langoustine)
This small, slender lobster is an important species in the North Sea and is found in the deeper sandy bottoms of Kosterhavet. It has a bright orange-pink color and is highly valued in seafood cuisine.

Velvet Swimming Crab
This aggressive and fast-moving crab gets its name from the fine hairs covering its shell, giving it a velvety texture. It is distinguished by its bright red eyes and is known for its quick movements in the water.

Edible Sea Urchin
Found in the rocky seabeds of Kosterhavet, the edible sea urchin is covered in sharp spines for protection. It plays an essential role in controlling algae growth and is a delicacy in Scandinavian cuisine.

Atlantic Cod
Once a dominant fish species in the North Atlantic, the Atlantic cod is an important predator in Kosterhavet’s ecosystem. It is recognizable by its whisker-like barbel on the chin and is a prized catch for fishermen.

Common Cuttlefish
A master of camouflage, the common cuttlefish can rapidly change its color and texture to blend into its surroundings. This intelligent mollusk is also known for its fascinating ability to squirt ink as a defense mechanism.

European Lobster
This deep-blue lobster is one of the largest crustaceans in Kosterhavet, living in rocky crevices along the seabed. It is highly sought after for its sweet and tender meat.

Ballan Wrasse
A colorful fish that plays a vital role in maintaining the health of marine ecosystems, the Ballan wrasse helps control populations of sea urchins and parasites on other fish. It is commonly found among kelp forests.

Ocean Quahog
A type of large clam that can live for more than 500 years, making it one of the longest-living marine animals. Found in the cold, deep waters of Kosterhavet, it is an important species for studying climate history through its shell growth rings.