Gadus morhua
The Baltic Cod
A Stock in Collapse
The Atlantic Cod (Gadus morhua) in the Baltic Sea is the same species as the North Atlantic giant, but today's eastern Baltic cod are small and thin - weakened by low oxygen, parasites and a shortage of food. The Baltic holds two stocks: the western stock in the Belt Sea and the Öresund, and the eastern stock, which spawns in the deep Bornholm Basin and in the 1980s spread as far as the Gulfs of Finland and Bothnia. In Finnish waters it is called Turska.
Baltic Sea 2026: targeted recreational cod fishing is prohibited in ICES subdivisions 22–32. In 22–26, accidentally caught cod must be released immediately. Only in 27–32 may incidental cod caught while lawfully fishing for other species be retained, subject to additional local conditions; this does not permit targeting cod.
The story is now one of collapse. By 2019 the eastern Baltic cod stock had crashed so severely - driven by hypoxic dead zones in the deep spawning basins, parasite loads, food-web shifts and overfishing - that the EU closed the directed fishery on the eastern stock, a closure renewed every year since. Anglers who still meet cod in the western archipelago are meeting the survivors of an ecological emergency, and the framing of any cod page must reflect that.
Cod are bottom-dwelling predators that hunt crustaceans and fish. Their food and habitat change with their size and the sea area. Research on the eastern Baltic stock focuses particularly on changes in the stock and its feeding conditions.
Season & activity
Activity patterns of Baltic Cod in Finnish waters - peak activity in cold months when oxygen-rich water reaches the basins, near-dormancy in stratified summer.
SourcesDiet Spectrum
Bottom-dwelling animals and fish are part of the Baltic cod's diet. Smaller cod take different sizes of prey from larger fish; accessible food on the bottom plays an important role in their development.
- Sprat
- Herring
- Benthic crustaceans
- Polychaetes
Growth at a glance
Length and weight as the animal grows.
Sources| Age (Years) | Length | Weight | Size comparison |
|---|---|---|---|
| 1 | 12 cm | 14 g | |
| 2 | 20 cm | 80 g | |
| 3 | 28 cm | 220 g | |
| 4 | 35 cm | 450 g | |
| 5 | 42 cm | 750 g | |
| 6 | 48 cm | 1.1 kg | |
| 8 | 58 cm | 2.0 kg | |
| 10+ | 68 cm | 3.2 kg |
Habitat Requirements
Water Temperature
- Typical conditions
- Cool water
- Other influencing factors
- Heat and oxygen shortage
Water temperature affects feeding and growth. Look for temperature zones that suit the species and season, from shallow shores to deeper areas.
Oxygen
- Typical conditions
- Adequate oxygen supply
- Other influencing factors
- Prolonged oxygen shortage
Currents, wind and mixing bring oxygen into the water. Temperature and water exchange help you find suitable places for fish to feed and shelter.
Structure
- Typical conditions
- Deep basin slopes, hard bottom edges
- Other influencing factors
- Soft anoxic mud, open water
Demersal - adults hold near rocky reefs and basin edges. Juveniles work shallower benthic habitat.
Substrate
- Typical conditions
- Sand, gravel, mixed hard bottom
- Other influencing factors
- Anoxic black mud
Spawning requires neutrally buoyant eggs to hold in oxygenated mid-water - increasingly rare as deep layers go anoxic.
Water Depth
- Typical conditions
- Depth varies locally
Depth use depends on oxygen, temperature and prey; 30–80 m is not a survival limit.
Water Type
- Typical conditions
- Sea water; ≥ 11 PSU to spawn
- Other influencing factors
- Low-salinity gulfs
A marine fish that copes with brackish water. In the Baltic, cod eggs need a salinity of at least about 11 PSU to develop, so the stock spawns only in the deep southern basins; the low-salinity Gulfs of Bothnia and Finland hold few cod.
Cod Fishing: Only Where It Is Legal
Baltic Sea 2026: targeted recreational cod fishing is prohibited in ICES subdivisions 22–32. In 22–26, cod caught while fishing for other species must be released immediately; only in 27–32 can incidental bycatch be retained under the applicable conditions. Swedish Baltic waters also have a 38 cm minimum for retention; that Swedish size rule is not a Finnish rule.
The methods below describe permitted cod waters, not an opening of the whole west coast. Gullmarsfjorden, the mapped Orust fjords and parts of the southern Kattegat have year-round closures. Elsewhere further rules apply, generally including a 30 cm minimum and January–March protection inside the trawl boundary; Brofjorden has separate conditions. Check the exact HaV area map before jigging, drift or shore fishing.
Vertical Jigging (Pirk)
Autumn & spring (west coast)Heavy 200-400 g pirks dropped to the bottom over rocky banks and wrecks. Slow lift-drop. Use barbless hooks if you plan to release.
Bait Drifting
Autumn & spring (west coast)Natural bait (herring strip, shellfish) drifted along the bottom. Effective but prone to deep-hooking - use circle hooks if you plan to release.
Shore & Pier Fishing
Autumn (west coast)Bottom rigs or small jigs are an option only at open locations. Bohuslän and Halland have local closures; cod angling is prohibited year-round in Gullmarsfjorden, the mapped Orust fjords and parts of the southern Kattegat. Elsewhere rules include January–March protection inside the trawl boundary and the local minimum sizes. Check the exact position, not just the destination name.
Slow Trolling
Autumn (west coast)Slow-pulled diving plugs along the slopes of deeper banks. Highly variable - expect blank days.
Where Cod Are Still Found in Finland
Cod encounters in Finnish waters are increasingly rare and concentrated in a few residual western-archipelago areas. Northern Bothnian waters are now essentially cod-free.
Outer Turku Archipelago / Åland Fringe
60.0°N, 21.5°ELast residual western refuge
The deeper outer-archipelago waters at the boundary with the Baltic Proper still hold occasional cod - the last reliable Finnish encounter zone, and even here fish are scarce.
Southern Bothnian Sea (Selkämeri)
61.5°N, 21.4°EMarginal - declining
Once a productive area, now sees only occasional fish. Encounters are increasingly accidental rather than targeted.
Hanko / Tammisaari Outer Coast
59.8°N, 23.2°ERare Gulf of Finland encounters
Eastern Baltic cod spread into the Gulf of Finland in the productive 1980s but are rare there today; occasional fish turn up along the deeper outer coast.
Bothnian Bay Southern Fringe
63.5°N, 22.6°ENorthern limit (essentially gone)
Cod are essentially absent from the Bothnian Bay today - salinity and oxygen conditions exclude them from this northern reach.
Conservation Notice
The eastern Baltic cod stock has been under EU directed-fishery closure since 2019 due to stock collapse driven by deep-basin hypoxia, parasite loads and overfishing. Treat every fish as a survivor of an ecological emergency; the conservation framing is not optional.
In mainland Finland, anglers aged 16 or over must also report incidental and released marine cod catches electronically to Luke each day, for example through Omakala. Include whether you fished from shore, boat, underwater or ice. Check Åland’s reporting requirements separately (Luke).
