European Flounder
The flounder is Ireland's most widespread flatfish and the go-to winter shore species when bass and mackerel have long since disappeared.
Native to Irish coastal waters, it turns up on sandy beaches, in estuaries, and well up into tidal rivers — accessible from almost any shore mark around the country.
Its willingness to take a simple bottom-fished bait makes it a natural first sea fish for beginners, while specimen-hunters chase the bigger autumn and winter fish in earnest.
Scientific Name: Platichthys flesus
Also known as Fluke, Flatties, Fladhóg
- Oval, diamond-shaped flatfish; upper side a mottled brownish or greenish-grey, sometimes with faint orange blotches; underside white.
- Distinguished from plaice and dab by touch: a line of small, rough prickles runs along the base of the dorsal and anal fins — run a finger along the lateral line and it feels distinctly rough.
- Smaller orange spots than plaice; smooth skin unlike the sandpaper-rough dab. Note that flounder and plaice can hybridise, making some individuals tricky to ID.
- Most Irish fish run well under 1kg; the specimen threshold sits at 1.10kg, and the Irish record is 2.23kg — a genuinely big flounder by any measure.
What to know
Habitat Distribution
- Native to Ireland and found around the entire coast on sandy and muddy bottoms in estuaries, harbours, surf beaches, and shallow inshore ground.
- Unusually tolerant of low salinity — juveniles push well up into tidal rivers and can spend extended periods in near-freshwater, making them catchable far from the sea.
- Adults move into deeper coastal water to spawn in winter, then return inshore through spring and summer.
- South and southeast coasts — Wexford bays, Cork estuaries, Kerry beaches — hold the highest concentration of specimen-sized fish, though flounder are present coast-wide.
Key Locations
- Youghal, Co. Cork — the Slob Bank estuary leads all Irish venues for specimen flounder submissions by a wide margin; classic flood-tide fishing on sandy ground.
- Ballyteigue Bay and Bannow Bay, Co. Wexford — consistently produce specimen-class fish from sandy estuary and bay marks on the southeast coast.
- Killybegs to Teelin, Co. Donegal — quality flounder from west coast beaches, with the odd larger fish showing through winter.
- Benone Strand and Portstewart Strand, Co. Derry — reliable north coast surf beach marks producing flounder through the winter months.
- Wicklow coast (Kilcoole, Brittas Bay, The Murrough) — a productive stretch for winter flounder accessible to Dublin-area anglers, with marks fishing well from October through March.
Specific Spots
- Estuary channels and gutters: flounder follow the tide up onto shallow sandy or muddy flats to feed, then drop back into the channel as the tide ebbs — work the flood through high water for best results.
- Surf beach troughs and gullies: depressions between sandbars concentrate worms and crustaceans; flounder sit in these natural larders, especially after a blow stirs up the bottom.
- Harbour walls and pier bases on sandy ground: sheltered from strong current, flounder hold tight to the bottom here and are easy to reach with a short cast.
- Tidal river banks just above the salt limit: on many Irish rivers, flounder push surprisingly far upstream — fish the bottom of pools and slack water on the inside of bends.
European Flounder FAQ
Answers from onWater's species guide.
What are the best lures and bait for European Flounder?
Lugworm and ragworm are the universal starting point, effective coast-wide and easy to source from tackle shops near most Irish shore marks.
When is the best time to fish for European Flounder?
October to March is the prime window coast-wide, bigger, better-conditioned fish feed hard ahead of spawning, and flounder are often the most reliable shore species through the darkest months.
How do you catch European Flounder?
Shore fishing accounts for almost all flounder caught in Ireland, a simple bottom-fished bait on a running ledger or paternoster rig, cast into estuaries, surf beach troughs, or tidal river banks.
What do European Flounder eat?
Adults eat mainly worms (lugworm, ragworm), molluscs, and crustaceans, which is why lugworm and ragworm are the standard baits, and peeler crab (a crab that has shed its shell) is often the most effective option, especially on southern marks.
Where do European Flounder live?
Native to Ireland and found around the entire coast on sandy and muddy bottoms in estuaries, harbours, surf beaches, and shallow inshore ground. Unusually tolerant of low salinity, juveniles push well up into tidal rivers and can spend extended periods in near-freshwater, making them catchable far from the sea.
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