Fishonomics/Bluefin Tuna
Florida Keys field guide

Bluefin Tuna.

Thunnus thynnus

Rare Keys winter visitor. Mostly a Carolinas/Northeast fishery.

Behavior

How they feed in the Keys

Atlantic bluefin tuna are rare in the Florida Keys. The species is a cool-water migratory predator that stages in the Carolinas, the Mid-Atlantic, and New England — only occasional fish (often juveniles) cross into Keys waters in winter. When they do show up, it's typically during cold-front pushes January–March. Targeting bluefin in the Keys is more of a long-shot bonus than a planned fishery — most Keys captains will tell you to fish further north for serious bluefin action.

Water temp

60–72°F

Active 55–76°F

Tide

Less direct (offshore).

Current

Stream edges concentrate fish when present.

Weather

Calm to moderate seas.

Pressure

Stable.

Time of day

All day at depth.

Moon phase

Less direct.

Tidal coefficient

Less direct.

Realism check

Most Keys anglers will not encounter bluefin in their lifetime locally. If targeting bluefin is a goal, plan a trip to Hatteras, Cape Cod, or the Maritime Provinces.

Seasonality

12-month outlook

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
PeakGoodOKSlowPoorSpawn window
Bait

What they eat, what catches them

Top 3 baits
1

Live mackerel

Live tinker mackerel or cero on a heavy circle. The standard if targeted offshore.

2

Live bonito

Bigger live bait for trophy fish.

3

Trolled ballyhoo (large)

Skirted ballyhoo + horse ballyhoo combos for searching.

Alternates
  • Vertical jigs· Heavy 400+ g jigs over deep structure.
When to use what
  • If you find them

    Heavy 80 lb class conventional + live mackerel + 130 lb leader + 10/0 circle. Hold on.

Gear

How top captains rig it

Line

80–130 lb mono or braid.

Reel

Heavy 50W–80W class with strong drag.

Rod

Bent-butt stand-up class.

Leader

150–200 lb fluorocarbon or mono.

Setups by situation
  • Targeted bluefin

    80 lb class conventional + 80 lb mono + 150 lb leader + 10/0 circle + live mackerel.

Regulations

Recreational rules

Size limit

27" curved fork length minimum (HMS Atlantic).

Bag limit

1 per vessel per day in some seasons; HMS rules vary by quota period.

Season

HMS Atlantic permit + reporting required. Quotas adjusted seasonally.

Prohibited methods

HMS rules apply. Fish must be reported.

Note · Bluefin harvest in the Atlantic is one of the most-regulated fisheries in the U.S. Always check NOAA HMS current rules before targeting; report harvested fish within 24 hours.

Recreational rules · FWCVerify current rules at FWC →
Bite-score factors

What actually moves the bite

Each factor is rated by how much it shifts the bite for this fish in the Keys. Calibrated against the Bite Score weights — see the Bite Score reference for what each factor measures.

Not ImportantImportant
Water Temp
95
Current Strength
85
Dawn / Dusk
70
Wind
70
Wave Height
70
Barometer
50
Moon Phase
45
Wind vs Sea
35
Incoming Tide
20
Outgoing Tide
20
Slack Tide
15
For sport fishing reference only · Not for navigationField guide · Fishonomics