Atlantic Halibut
Atlantic halibut are the largest flatfish in the world and a rare but genuine target in Irish offshore waters.
They're seldom fished for deliberately here — most are caught by accident — but the fish exist along Ireland's north and west coasts, particularly around deep offshore reefs.
The Irish record of 156 lb, taken off Belmullet in 1972, hints at what's possible for anglers willing to fish the right ground seriously.
Scientific Name: Hippoglossus hippoglossus
Also known as Halibut
- Elongated diamond-shaped body, dark mottled brown on top and white or cream underneath; older fish may show grey or reddish mottling on the blind side.
- Distinguished from other flatfish by a concave (inward-curved) tail fin and a strongly arched lateral line rising sharply above the pectoral fin.
- Large gaping mouth armed with sharp, curved teeth — handle with care when unhooking.
- Typical rod-caught fish run 30–90 lb; the Irish record stands at 156 lb, and fish exceeding 300 lb have been taken commercially.
What to know
Habitat Distribution
- Native to the cold North Atlantic; Ireland sits near the southern edge of its European range, with fish present along the north and west coasts.
- Primarily a deep-water, bottom-dwelling species found over sand, gravel, and clay substrates — not soft mud or bare rock.
- Depths of 50–2,000 m are recorded, but most rod-caught fish come from offshore reefs and broken ground in the 50–200 m range.
- Historically found throughout Irish waters; current distribution is not well documented, but divers and commercial fishermen report large fish on north-coast offshore reefs.
Key Locations
- Belmullet (Co. Mayo) — site of the Irish record; the offshore pinnacles known as The Stags hold suitable reef ground, though strong currents make access challenging.
- North coast offshore reefs — divers and commercial fishermen have reported large halibut regularly on deep reef systems off the north coast of Ireland.
Specific Spots
- Offshore pinnacles and reef systems with strong tidal current — the fish use current edges to intercept prey moving along the bottom.
- Broken ground adjacent to sandy or gravel flats, where halibut can move onto the flat to feed and retreat to structure.
- Deep-water drop-offs and gullies between reef systems, particularly where baitfish like coalfish and pollack concentrate.
Atlantic Halibut FAQ
Answers from onWater's species guide.
What are the best lures and bait for Atlantic Halibut?
Whole live or freshly killed baitfish, coalfish, pollack, mackerel, or whiting, are the most effective baits; present them on a running ledger rig or paternoster that keeps the bait just off the bottom.
When is the best time to fish for Atlantic Halibut?
Can be encountered year-round, but the most productive period in British and Irish waters is broadly summer through autumn. Offshore reef fishing for other species during the warmer months gives the best incidental opportunity, as boat access to exposed north and west coast marks is weather-dependent.
How do you catch Atlantic Halibut?
Halibut are almost exclusively targeted from a boat, drifting or anchoring over deep offshore reefs and broken ground. The standard approach is to present a large whole baitfish on a heavy ledger rig, keeping it near the bottom in areas of tidal current.
What do Atlantic Halibut eat?
Primarily other fish, cod, haddock, coalfish, pollack, sand eels, herring, and mackerel, making large whole or strip baits the most direct imitation; a whole live or freshly killed coalfish or mackerel is the go-to bait in Irish and British waters.
Where do Atlantic Halibut live?
Native to the cold North Atlantic; Ireland sits near the southern edge of its European range, with fish present along the north and west coasts. Primarily a deep-water, bottom-dwelling species found over sand, gravel, and clay substrates, not soft mud or bare rock.
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