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Flounder
Flounder (Platichthys flesus), A lean bottom-feeder low in the food chain; watch for local harbour advisories.. The national eating advice, why it applies, the rules that matter when you catch it, and what the kitchen changes about the numbers.
Where it lives
The flatfish of the Baltic, and one of the few sea fish an ordinary person can catch from a shore or a small boat without specialist gear. Flounder lies on sandy and muddy bottoms in shallow water, moves inshore in summer, and is taken on bottom rigs, in nets and in traps along the whole coast from the Gulf of Finland to the Gulf of Riga.
Why the advice says what it says
A flounder eats molluscs, worms and crustaceans off the bottom. That is a low position in the food chain, and it shows: flounder is lean, its mercury is low, and it appears in no national frequency advisory. The one thing worth knowing is what "off the bottom" implies. A bottom-feeding fish is in permanent contact with sediment, and sediment is where a century of harbour, shipyard and industrial discharge ends up. That is a local question, not a species question: the general advice on flounder is unrestricted, but specific harbours, river mouths and former industrial basins in this region carry their own local advisories against eating fish caught there. If you fish inside a working port or downstream of an old industrial site, look for a local notice before you look at a species page.
The advice
| Who it applies to | What the advice says | Where it comes from |
|---|---|---|
| Everyone | No frequency restriction. A lean, low-trophic fish. | Finnish Food Authority (Ruokavirasto) general fish advice |
| Anyone fishing inside harbours or old industrial basins | Check for a local advisory on the specific water. Sediment contamination is site-specific and is not covered by species-level advice. | National and municipal local advisories |
The rules
What the rule book says about this fish, described by instrument rather than printed as a number:
- Minimum sizes and area closures for flatfish exist in parts of the Baltic and differ by country and by coastal zone.
- Spawning closures apply in some areas in spring.
- Net and trap fishing along the coast needs the local gear permit even where rod fishing does not.
- Where a port authority or municipality has posted a local eating advisory, that notice is the operative rule for the catch, whatever the fisheries rules say about keeping it.
In the kitchen
Flounder is usually cooked whole: scored, floured and pan-fried, or baked. Skinning the dark side is the traditional first step and is also the sensible one, since skin is where a bottom fish carries most of what little fat it has. The flesh is delicate and sweet, and the fish is thin enough that it goes from underdone to overdone in about a minute.
This is a reference page, not a fishing licence and not medical advice. Minimum sizes, closed seasons, bag limits and licence prices are set per country and per water body and change most years, so no number for them is printed here — each species page says which instrument sets the rule and where to look up the figure for the water you are standing on. If a clinician has given you a fish frequency or a contaminant instruction, that instruction outranks anything on this page.
Nutrition figures
| Per 100 g, raw | Amount |
|---|---|
| Energy | 70 kcal |
| Protein | 12.4 g |
| Fat | 1.9 g |
| Carbohydrate | 0 g |
| Fibre | 0 g |
| Salt | 0.7 g |
| Published row | Flounder and sole, raw |
Related published rows:
- Flounder and sole, cooked — 86 kcal per 100 g
- Turbot, raw — 95 kcal per 100 g
Typical round weight for the calculator: 200–800 g.
Eating advice: Finnish Food Authority and Swedish Food Agency national advice on Baltic and inland fish. Contaminant ceilings and the Baltic derogation: Regulation (EU) 2023/915; weekly tolerable intakes: EFSA methylmercury (2012) and dioxins/dioxin-like PCBs (2018). Nutrition figures: USDA FoodData Central rows published on this site. Checked 2026-09-06.
Frequently asked questions
Is it safe to eat fish caught in a harbour?
That depends entirely on the harbour, which is why species-level advice cannot answer it. Sediment contamination is local, it is measured locally, and where it is a problem the authorities post an advisory for that specific water. Look for the local notice; the absence of one is not the same as having read one.
Fish in the same advice group
Cod
Lean and low in mercury; the problem with Baltic cod is the stock, not the fillet.
Garfish
A spring visitor with alarming green bones that are entirely harmless.
All species compared
The full table, grouped the way the advice groups it.
Eat the fish, log the fish
TempoLife tracks what you actually ate against the same food data linked on this page, so a fish meal shows up in your omega-3, vitamin D and salt totals without a second thought.