Atlantic Bluefin Tuna
Atlantic bluefin tuna show up along Ireland's west and southwest coasts each autumn, following mackerel, herring, and other baitfish into inshore waters.
After decades of near-absence caused by overfishing, they've returned in real numbers — particularly to Donegal Bay and the waters off Kerry and Galway.
Under Ireland's Tuna CHART programme, anglers can target them on authorised charter boats on a strict catch-and-release, tag-and-release basis only.
Scientific Name: Thunnus thynnus
Also known as Bluefin, Giant bluefin, BFT
- Torpedo-shaped body, nearly circular in cross-section; dark blue-black on the back, silvery-white on the lower sides and belly with faint colourless spots.
- Short pectoral fins (less than 80% of head length) and a reddish-brown second dorsal fin — key features that separate bluefin from other large tuna.
- Fish recorded in Irish waters typically run around 2 m in length; the species can exceed 4 m and 900 kg, though giants over 1,000 lb were historically reported from commercial catches off Kerry and Donegal.
What to know
Habitat Distribution
- A highly migratory oceanic species — not native to Irish waters in a resident sense, but a regular seasonal visitor to the west and southwest coasts in autumn.
- Tagging data shows fish tagged off Donegal have subsequently turned up off Spain, Portugal, and in the Mediterranean, confirming these are wide-ranging eastern Atlantic stock fish.
- In Irish waters they're pelagic, hunting near the surface and in the mid-water column, typically over open water rather than structured ground.
- Donegal Bay, the waters off Kerry, and the Galway/Aran Islands area are the most documented locations under the Tuna CHART programme.
Key Locations
- Donegal Bay — the most documented location in Ireland, with consistent annual returns of fish and a base for several authorised CHART skippers operating out of Mullaghmore.
- Kerry coast — fish tagged off Kerry have been recaptured off northwest France; authorised boats operate out of ports along this coastline.
- Kinsale and Baltimore (Cork) — authorised charter operators based here cover the southwest approaches where bluefin follow baitfish inshore.
- Aran Islands / Cleggan (Galway/Connemara) — authorised boats cover the Aran Islands to Achill Head corridor, a productive stretch of the west coast.
Specific Spots
- Look for working birds and surface boils over baitfish schools — bluefin herd mackerel and herring to the surface and feed visibly when conditions allow.
- Concentrations of mackerel or scad are the single best locator; where the bait is, the tuna follow, often in open water well offshore.
- Donegal Bay's inshore grounds have produced consistent action, with fish sometimes visible from shore — but most trips run 10–30 miles out depending on where bait is holding.
Atlantic Bluefin Tuna FAQ
Answers from onWater's species guide.
What are the best lures and bait for Atlantic Bluefin Tuna?
Fresh or live mackerel is the primary bait used on Irish Tuna CHART trips, trolled whole or rigged as a dead bait behind the boat at speed.
When is the best time to fish for Atlantic Bluefin Tuna?
Season opens 1 July under the Tuna CHART programme, though fish are rarely encountered this early. Peak fishing runs September through November, when bluefin are most reliably inshore along the west and southwest coasts following autumn baitfish concentrations.
How do you catch Atlantic Bluefin Tuna?
All bluefin fishing in Ireland runs through the Tuna CHART programme on authorised charter boats, anglers book a full-day trip, troll mackerel baits or large lures over open water, and all fish are tagged and released as part of the scientific programme.
What do Atlantic Bluefin Tuna eat?
In Irish waters, bluefin feed heavily on mackerel, herring, and scad, the same schooling fish that draw them inshore each autumn. Trolled or live mackerel is the standard bait on Irish charter trips. They also take squid and will chase smaller baitfish opportunistically.
Where do Atlantic Bluefin Tuna live?
A highly migratory oceanic species, not native to Irish waters in a resident sense, but a regular seasonal visitor to the west and southwest coasts in autumn.
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