Saltwater · Spring and fall peaks; around the Keys reefs much of the year

Blackfin Tuna

Thunnus atlanticus

The Atlantic's pocket tuna — blackfin school over Keys humps and Gulf ledges at dawn, out-pull their size by a mile, and eat better than any other small tuna.

Seasons · Peak

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Blackfin Tuna — Photo: Williams, J. T.; Carpenter, K. E.; Van Tassell, J. L.; Hoetjes, P.; Toller, W.; Etnoyer, P.; Smith, M., CC BY 2.5 — Wikimedia Commons

Identifying features

Dark metallic back separated from the white belly by a clean line; no stripes or bars on the belly
Short pectoral fins that do NOT reach the second dorsal fin — the key separator from other small tunas
Fins are dusky, and the finlets behind the dorsal and anal fins are dark-centred, not fully black
Torpedo tuna body, smaller and slimmer than skipjack
Look-alike: skipjack tuna have bold black horizontal stripes on the lower belly; blackfin bellies are plain white

Habits

Schools over reef edges, wrecks and ledges, often mixed with skipjack tuna
Feeds on small fish, squid and shrimp — frigate birds and surface splashes give the schools away
A dawn specialist: the bite frequently fires at first light and fades by mid-morning
Migrates along the Atlantic coast and through the Gulf with water temperature

Distribution

Galveston, TX · Gulf Coast★ Primary

Tampa, FL · Florida★ Primary

Norfolk, VA · Mid-AtlanticCommon

Charleston, SC · SoutheastCommon

Where to find them

The humps and reef edges off Islamorada and Key West
Gulf Stream edges and weed lines off southeast Florida
Northern Gulf ledges and oil rigs in summer

Where they live

Offshore rips and weed linesReef edges and wrecksLedges near the Gulf Stream

How to catch them

Trolling feathers at dawn

Rig: Small feather lures trolled 6-8 knots along rips and reef edges

Bait/lure: Feathers in green, pink or black/red

Key tip: Be on the spot before sunrise; the first hour is the blackfin hour.

Live-chumming the school

Rig: Light conventional gear, small circle hook through the bait's nose

Bait/lure: Live pilchards, with freebies thrown to hold the school

Key tip: Keep a trickle of live chum going and drift your bait back with it — no weight.

Best baits & lures

Small feathers and cedar plugs trolled fastLive pilchards chummed to the transomSmall spoons and jigs cast to surface schools

Techniques Academy →

Baseline setup

Rod: 6'6"-7' medium conventional or heavy spinning rod
Line: 20-30 lb mono or braid
Terminal: Feathers, cedar plugs, small circle hooks for live bait

Recommended gear for this species

Rod · Best value

9' 5-weight fly rod outfit

≈ US$180-260

Covers chironomid lakes and small rivers with one setup.

Flies · Budget

Chironomid assortment (30 patterns)

≈ US$25-40

Chironomids are 60% of a lake rainbow's diet in spring.

Picks come from our rule library — never paid placements. Prices are guides; affiliate links may earn us a commission.

Typical size

Common 5-15 lb; large specimens 25-35 lb

On the table

The best-eating of the small tunas — dark red loin meat, far richer than skipjack; sear it rare or use it fresh.

Similar species

Skipjack TunaSkipjack have 4-6 bold black stripes running along the white lower belly; blackfin have an unmarked white belly and dusky finlets

Little TunnyLittle tunny (false albacore) wear a marbled 'worm' pattern on the back and scattered fingerprint spots below the pectoral fin; blackfin backs are plain dark

Regulations vary by area and can change in-season — always check the official rules for your area before you fish. Regulations guide →

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