Kosterfjord
Sweden · Europe
Kosterfjord is home to Sweden's first and only marine national park, Kosterhavet, established in 2009. The fjord plunges to over 240 metres and channels nutrient-rich Atlantic water from the Norwegian Trench — making it the most species-rich marine environment in Scandinavia. Cold, clear water feeds extraordinary macro life: hundreds of nudibranch species, sea spiders, horse mussels the size of dinner plates, and dense fields of sea urchins carpeting rock walls. Dead man's fingers soft coral and sea fans colonise near-vertical walls. The protected status means visibility and biodiversity are exceptional for a temperate site.
How this reef is doing
ⓘ How we measure thisReef state
Live science signals for this reef are still being gathered.
Coral cover
Fish life
Heat
Fishing
Open to fishing, and the water is busy.
Sources · Global Fishing Watch and reef gravity
What you will see
36 species across the dive sites here
Dead Man's Fingers
Seen 2 months ago
at Saltö Wall
Common Starfish
Seen 3 months ago
at Nordkoster Urchin Fields
Horse Mussel
Seen 7 months ago
at Saltö Wall
Plumose Anemone
Seen 10 months ago
at Saltö Wall
Green Sea Urchin
Seen 11 months ago
at Nordkoster Urchin Fields
Common Tunicate
Seen 11 months ago
at Nordkoster Urchin Fields
Oarweed
Seen 11 months ago
at Stängselrevet Reef
Common Lobster
Seen Jul 2025
at Stängselrevet Reef
Least concern
Sugar Kelp
Seen Jun 2025
at Stängselrevet Reef
Norway Lobster (Langoustine)
Seen Apr 2025
at Koster Trench
Least concern
Pollock
Seen Jan 2025
at Nordkoster Urchin Fields
Blue Mussel
Seen Dec 2024
at Stängselrevet Reef
Spider Crab
Seen Nov 2024
at Koster Trench
Limacia Nudibranch
Seen Oct 2024
at Saltö Wall
Northern Stone Crab
Seen Sep 2024
at Stängselrevet Reef
Deep-sea Prawn
Seen Jul 2024
at Koster Trench
Wolffish
Seen Jul 2024
at Koster Trench
Sea Anemone (Cup Coral)
Seen Jun 2024
at Koster Trench
Arctic Starfish
Seen year round
at Saltö Wall
Brittle Star
Seen year round
at Koster Trench
Dahlia Anemone
Seen year round
at Stängselrevet Reef
Edible Crab
Seen year round
at Nordkoster Urchin Fields
Encrusting Sponge (Orange)
Seen year round
at Saltö Wall
Flabellina Nudibranch
Seen year round
at Saltö Wall
Giant Sea Spider
Seen year round
at Saltö Wall
Onchidoris Nudibranch
Seen year round
at Saltö Wall
Purple Sea Urchin
Seen year round
at Stängselrevet Reef
Stalked Crinoid
Seen year round
at Koster Trench
Velvet Swimming Crab
Seen year round
at Nordkoster Urchin Fields
Ballan Wrasse
Seasonal visitor
at Saltö Wall
Coryphella Nudibranch
Seasonal visitor
at Nordkoster Urchin Fields
Leafnose Sculpin
Seasonal visitor
at Koster Trench
Leopard-spotted Nudibranch
Seasonal visitor
at Stängselrevet Reef
Painted Goby
Seasonal visitor
at Stängselrevet Reef
Least concern
Sea Cucumber
Seasonal visitor
at Koster Trench
Least concern
Sea Scorpion
Seasonal visitor
at Nordkoster Urchin Fields
Least concern
Dive sites
Saltö Wall
dead man's fingers · flabellina nudibranch · onchidoris nudibranch · limacia nudibranch
Koster Trench
norway lobster (langoustine) · spider crab · stalked crinoid · horse mussel
Stängselrevet Reef
sugar kelp · oarweed · common lobster · painted goby
Nordkoster Urchin Fields
green sea urchin · edible crab · velvet swimming crab · coryphella nudibranch