Bluefin Tuna on the Fly

<Editor’s note: this article was first published by in either 1999.  Some of the info may be considered out of date by today’s standards.  mncahill>

Many regard bluefin tuna as the most powerful fish that visits the Northeast waters and many fishermen consider bluefin the ultimate big game fish. Depending on weather, ocean currents and availability of bait, the northern bluefin, Thunnus thynnus, appears in Massachusetts waters around the first part of July.

All about Bluefin Tuna

big-poseIn the North Atlantic, two separate stocks of northern bluefin are present, the West Atlantic stock which spawns in the Gulf of Mexico and the East Atlantic stock which spawns in the Mediterranean Sea. Most likely, fish from both stocks co-exist when in Northeastern waters. Schoolie bluefin (2 to 4 years old from 15 to 135 pounds), which fly fishermen seek, start their seasonal feeding migration through the continental shelf from Hatteras to Cape Cod and the Gulf of Maine. They then leave New England waters when the water temperature drops below 50 oF. They go east to the Sargasso Sea near Bermuda or they stay near the boundary currents of the Gulf Stream. More mature bluefin (four years and older) move a bit differently — they appear to make spawning runs to the Gulf of Mexico and enjoy the warm water from February to May. After spawning, bluefin begin their journey past Bimini, the Carolina and Virginia Outer banks, New Jersey’s Mud Hole, Montauk and Cape Cod to the Canadian provinces of Nova Scotia and Newfoundland. In the fall, they return to their primal spawning grounds to complete the centuries old migration ritual.

In Massachusetts during the early part of the bluefin season (July), schoolies can be found east of Chatham and south of the Vineyard inside the 25 fathom curve. Later in the season (September-October), as the water temperature drops, schoolie bluefin congregate at Stellwagen Bank where they feed extensively as they prepare for their southerly migration. Traditionally, the waters of Cape Cod Bay and particularly Stellwagen Bank, were fished by commercial and recreational anglers for giant bluefin tuna. But in the last two years, schools of smaller tuna started to show up in large numbers at the locations historically roamed by giants.

The regulations for bluefin tuna are administered by the National Marine Fisheries Service, a Division of National Oceanic and Atmospheric Administration. The fishing dates and quotas for tuna are established every year depending upon the apparent health of the populations. The 1999 regulations allowed fishermen possessing a tuna licence to keep two schoolies per day in 27 to 47-inch range until October 6, one large schoolie per day in the 47 to 59-inch range throughout the season, and one giant over 71 inches per year.

Top Techniques

If you have decided to go for bluefin, here are my personal recommendations for success. I have found that following these steps results in landing what you are after. As I mentioned, a combined knowledge of ocean elements such as bottom surface configurations, water temperature breaks, water color and current, are essential when trying to locate tuna. Thoroughly studying a navigational and temperature chart before departing are two necessary activties. A few private companies supply ocean temperature charts and you can get these via e-mail. When looking at the chart, look for warm water breaks – zones of warm core eddies and filaments. If you combine these with areas of dramatic bottom contour you can determine potential tuna hotspots.
When reaching your targeted areas, the presence of whales on the surface often indicates a supply of forage that bluefin may be working over in the depths below, as do the indications of schools on your depthfinder.

bustingWhen going after bluefin with a fly rod, fishermen have to bring the fish within fly-casting range and entice bluefin to strike a fly. Three approaches can be applied to achieve this. Chummingand chunking, although the most labor intensive method, is potentially the most effective. The first key to chumming is to anchor or drift on the edges of prominent “structure” as indicated on your depthfinder and chart. The type of bait presented to the fish can mean the difference between raising tuna to the surface or not. While chumming and chunking at Stellwagen, small pogies, mackerel or bluefish can be used to develop the chum slick. Butterfish are my first choice at locations south from the Vineyard. Adding a small amount of menhaden oil to the ground fish is a good idea so the chum slick is reinforced but without adding additional food, which could diminish the hunger of the tuna, making chunking, is essentially tossing balls of ground fish over the side of the boat at a regular rate. After fifteen minutes of chumming or when fish begin to show up, small chunks of cut bait are thrown into the chum slick to keep the tuna around the boat. When using this approach one person can toss the bait and watch the depthfinder while the other person is prepared to cast to the rising fish. Repeatedly cast your fly (selection recommendations appear further on in article) into the slick and strip it back at various speeds, starting with a fast retrieve and ending with the dead-drifted fly. For most of the situations a fairly long casts 50 to 70 feet are necessary.

Trolling is the second technique commonly employed to tease tuna to surface. It is more gear intensive and primarily used to locate fish rather than to attract. The fisherman is trying to mimic the underwater environment by creating a mini-ecosystem composed of the artificial lures. I recommend putting out a minimum of 2 hookless spreader bars containing squid of uniform size (ranging from 7 to 11 inches) and color (green, natural or purple). On each spreader bar, attach a straight running lure, like green machines behind the last middle squid. The spreader bar should be set approximately 25 feet behind the boat. Although the final distance should be adjusted based on squid performance. Keep the bar out of the water to give the spreader bar lures the most realistic presentation. On two additional rods set a combination of a bird (medium sized) followed by lure (about three feet behind the bird). These two riggings are set on either side 100-150 feet behind the spreaders. Lastly, a final lure is set 100 feet behind the bird-lure combination. This lure is on a third rod which is set in the middle of the stern. Another important point to remember. When configuring your trolling spread, try to include a variety of lures, such as feathers, Yo-Zuri (Hydro Tigers or Magnums), Rapala (CD22 or CD26 Magnums) and skirted lures.

You never know what will attract the bluefin to your setup. Once you start trolling (6-8 knots) it’s important for everybody to stay focused on the trolling set up. As soon as a tuna strikes one of the trolled lures, the captain puts the boat into neutral, and immediately, the fisherman should start casting towards the trolling set. Although there is only one fisherman at any time, this approach is a team effort requiring at least one, but ideally two, additional anglers. One crew member starts throwing chunks over the side of the boat while the other crew member clears the trolling setup. If there are only two people on the boat, one has to initiate chunking and clear all lines while the second is casting. If a tuna does not strike your fly within 20 minutes, resume the trolling.

Lastly, when fishing is really hot and bluefin are actively feeding on the surface, try to determine the direction the school is traveling, motor about 100 yards ahead of them, turn the engine off and drift. Bluefin are sensitive to engine noise so leave adequate distance driving around them. At these times, the abundance of fish offers an excellent opportunity to cast the fly without having to tease fish.

Gearing Up

When gearing up for your trip, it is crucial to know the habits of bluefin. Tuna routinely feed below the surface, therefore fast-sinking lines are your best choice. A sinking shooting head in 500 to 750 grain range is my preferred type of line for bluefin, regardless of the technique used. This line presents the fly to deeper locations and placing the at the fish’s feeding level is always important. When tuna are on the surface, use a fast retrieve but they are down, let the fly and line sink for approximately twenty seconds to get the fly down to twenty feet before starting to retrieve.

Also critical is the realization that bluefin of all sizes are extremely, so your equipment has to match the quarry. A 12-weight rod is a good choice. This rod usually has a foregrip which helps tremendously when pumping the bluefin up from the depths. Although stiffer, higher weight class rods could be more beneficial during the long fight, I recommend using a 12 weight rod over the heavier sticks particularly when fishing relatively shallow waters. The weight and action of the heavier sticks makes casting relatively large flies muchmore difficult. Casting may be less of a factor while chumming and chunking, but it definitely plays a major role during trolling and drifting and, regardless of rod weight, the maximum amount of pressure an angler
can exert whole fishing with a 20 pound test tippet can not exceed six pounds anyway. Thus the lighter rod is better as it affords greater finesse while playing the fish.

However, when fishing at locations where the water depths range from 50 to 100 fathoms, fishermen have no choice but to use heavier rods. At these locations, bluefin typically make a long, powerful run and then sound into the depths to their “comfort zone”. The fisherman then has a hard time to recover every inch of line and the battle is usually long and will keep your undivided attention for hours.

Reels have to match the rods and the fish, and therefore, should hold a minimum of 600 yards of backing. Large arbor, fast retrieve reels will do the trick. Tuna move through water with great speed, so to minimize water pressure on the line, use only 15 feet of shooting head followed by 50 feet of running line, attached using double Bimini twists to ultra thin backing, such as 30-pound Spectra. If you decide to use thin backing, just watch your fingers when the fish takes off. The leader does need to be longer
than 5 feet and can be made from RIO Product IGFA monofilament and a fluorocarbon tippet (10 to 12 inches of 60 or 100 pound). The class tippet is made by tying double Bimini twists, one within the first foot of the butt section and one at the end of the butt section. Then tie a nail knot in front of the Bimini using heavy fluorocarbon line. The connection between the class tippet and heavy fluorocarbon tippet is made by tying 3 to 5 half Huffnagle knots and one full Huffnagle knot.

Flies for the Challenge

flies1Depending what the bluefin are feeding on at a particular location, the selection of flies could include sand eel patterns, or small bluefish and mackerel imitations. Keep in mind that the more closely the fly represents what the tuna are feeding on, the more likely it will be to trigger a strike. If you troll lures, observe which are being hit and while selecting the fly, try to mach the size and color of the lure. Light intensity can be a factor so try different colors (darker and then lighter or reverse) of
the same imitation. I have had great luck with a Sea Habit tied in green, blue or purple dorsal, 6 inches long with a 6/0 stinger hook.

Prior to landing bluefin, I had guided and landed numerous “big game” species. These experiences have brought me to believe that blue water fly fishing represents one of fishing’s greatest challenges. You may be ambivalent about the blue water at first, but eventually it will beckon.


Mark N. Cahill has been writing and editing for since 1995. He started fishing in the mid-1960's and caught his first striper off World's End in Hingham in 1966. From there on in it was an obsession. He loves fishing for tuna, and fly fishing for striped bass. In a pinch, anything with fins will do...

Posted in Bluefin Tuna, Saltwater Fly Fishing

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