Brill
Brill are native flatfish found around the Irish coast, though numbers have dropped significantly in recent decades. Once a regular catch over offshore sandbanks, a specimen-sized fish is now genuinely rare.
Anglers targeting plaice, turbot, or rays on sandy ground may still encounter them, and dedicated flatfish boats working Donegal, the northwest, and Cork waters turn them up occasionally.
Scientific Name: Scophthalmus rhombus
- Oval-bodied flatfish, more elongated than the diamond-shaped turbot — smooth brown skin with scattered lighter and darker flecks, creamy-white underside; flecking stops at the tail fin.
- Both eyes sit on the left side of the body; the leading edge of the dorsal fin is distinctly frilly, with the first rays free of the fin membrane — the clearest visual difference from turbot.
- Turbot has rough, bumpy skin (tubercles); brill has small smooth scales — run a finger across the back to tell them apart quickly in hand.
- Irish record stands at 9lb 8oz; specimen weight is set at 3.53lb (1.6kg), reflecting how scarce larger fish have become in Irish waters.
What to know
Habitat Distribution
- Native to Irish coastal waters; present all around the coast but more common in southern areas, with records from Donegal, the northwest, and Cork Harbour.
- Sandy and muddy seabeds are the preferred ground — the same offshore sandbanks that hold plaice and turbot.
- Juveniles tolerate shallow water and can turn up in estuaries and sheltered bays; larger adults move into deeper water, typically 10–70m.
- Brill can handle brackish conditions, so estuarine marks and sheltered inlets are worth fishing, particularly for smaller fish.
Key Locations
- Mulroy Bay and the Donegal coast — sheltered inlets and offshore sandbanks have produced brill, including fish from charter boats out of Downings.
- Causeway Coast sandbanks (Dunseverick, Ballycastle, Red Bay) — historically productive offshore marks for mixed flatfish including brill.
- Belmullet, Co. Mayo — west coast sandbanks have yielded fish, typically juveniles in recent years.
- Cork Harbour — southern Irish waters hold brill and the harbour has a record of producing fish for boat anglers targeting flatfish.
- Kilkeel and Castletownbere — both ports land brill commercially, indicating fish are present in the surrounding offshore grounds.
Specific Spots
- Offshore sandbanks are the primary marks — brill lie flat on clean sandy bottom and move onto the bank edges to intercept baitfish moving with the tide.
- Current edges and tide runs over sand are productive; the flowing trace method works because it keeps bait moving naturally just above the bottom where brill are hunting.
- Sheltered bays and inlets along the Donegal coast, including Mulroy Bay, hold fish — calmer water concentrates smaller brill, especially in summer.
- Cork Harbour and the sandbanks off the Causeway Coast (Dunseverick, Ballycastle, Red Bay) have produced fish historically; boat anglers working these marks for mixed flatfish are most likely to encounter brill.
Brill FAQ
Answers from onWater's species guide.
What are the best lures and bait for Brill?
Whole sand eels or launce (fresh or frozen) on a long flowing trace are the top brill bait in Irish waters, rig them to flutter in the tide rather than lying static. Long mackerel belly strips or mackerel fillet sections are a reliable alternative; cut them into a tapering strip so they move in the current.
When is the best time to fish for Brill?
Late spring through early autumn (May–October) produces the most consistent catches, with June and July generally the peak months in Irish waters. Brill can be caught year-round, but winter fishing is much less productive as fish move into deeper water and feed less actively.
How do you catch Brill?
Boat fishing over offshore sandbanks is the most reliable approach in Ireland, using a long flowing trace baited with sand eel or mackerel strip and worked with the tide.
What do Brill eat?
Sand eels and launce (greater sandeel) are the primary forage, long launce fillets or whole sand eels on a flowing trace imitate this directly and are the top brill baits in Irish waters.
Where do Brill live?
Native to Irish coastal waters; present all around the coast but more common in southern areas, with records from Donegal, the northwest, and Cork Harbour. Sandy and muddy seabeds are the preferred ground, the same offshore sandbanks that hold plaice and turbot.
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