As suggested in its name this member of the Tuna has bright yellow fins. The finlets, in particular are canary yellow with black margins and the caudal fin is distinctly notched in an “M” shape at the centre of its fork. Behind the second dorsal fin and the anal fin, the body profile of the Yellowfin tuna is somewhat flat. Its black to iridescent blue back and silver to bright gold flanks are magnificent.
Yellowfin tuna adults are distinguished by having a moderately long pectoral fin that is one third to one quarter its body fork length and the second dorsal and anal fins may be exceedingly elongated. In juveniles there are about 20 broken pale lines crossing the fish’s lower sides. Yellowfin tuna have been recorded in excess of 150kgs and being a very good eating fish they are hunted by the world’s commercial fishing fleet. They are also known as the hardest fighting Tuna in the sea. Yellowfin Tuna can be found close inshore when there are clean warm currents, but are more common on the continental shelf areas. They prefer clean water with water temperatures of 17-27C. Their diet consists essentially of other fish and squid.
When targeting the super-sized bluewater game fish of the Indian Ocean you are going to need a rod with a lot of lifting power, yet you dont want to compromise on the cast ability. Match the rod with a high quality machined large arbor reel with a capacity to handle a heavy fly line and a large amount of backing.
There are three ways which can be used by themselves or combined to target Yellowfin Tuna. Anglers can blind cast, use chum or teas the fish to the surface. The tactics are varied slightly depending on what works best at the particular venue.
The skipper will target structure like a pinnacle, wreck or drop-off that is not too deep as to allow you to target the fish drawn to it. He will then position the boat as to allow you to cast up current and get your fly to sink to the structure. Even though you will be blind casting, with the aid of modern day eco sounders you will have a good idea weather there are fish present or not. Use a long leader and a heavy fly that will sink quicker than your fly-line, as to allow your target species to see the fly before the fly-line. Always use a full fly-line whether it be a full-sink or sink-tip. Reason being is that often a fish will take at full length and you do not want to end up trying to set the hook with backing or braided running line in your hand.
Often the combination the above mentioned tactics and the use of live bait or chunking works best as it allows you to draw fish from deeper areas. Chunking is the use of finely cut up fish pieces thrown in the water to make a chum line. Once you have found your target area its often best to set anchor or a parachute as to allow you to concentrate on one spot. Off Cape Town in South Africa the Aft of Hake trawlers are often targeted as they often attract large amounts of feeding Yellowfin.
Blind casting with the aid of live bait
With the use of a sounder the skipper will target a pinnacle, wreck or drop-off which is holding fish. Once he is convinced a suitable area has been found communication will be made with a crew member to start chumming, at the same time he will imitate predators attacking a bait ball by doing a series of tight circles with the boat After a couple of rotations the engines will be turned off and the chumming will continue. It will take a few minutes, but this will often bring the fish to the surface allowing you to get a few casts in. The secret is to use just enough live bait to keep them coming to the surface as too much will take the emphasis away from your fly. When selecting your fly pattern always try to match the size and colour of your live bait. This is a process that needs lots of live bait, an experienced skipper and crew.
When teasing for Yellowfin Tuna the FlyCastaway guides have found that 2 methods work well. Firstly, trolling drop-offs and structure with bullet-head or soft-head skirts in red and black, green and chartreuse or blue and white works well. As in the case of all teasing having a belly shine or halfbeak adds to the attraction, the fishy taste often brings a hotter shoal of fish to the boat, giving you extra time to make your cast. (If you have live bait its the best way to hold the fish at the boat). Also remember that the engines should be in neutral before the cast is made, other wise its not considered as fly fishing. The optimum speed to troll teasers solely for Yellowfin Tuna is between 6 and 7 knots, depending on sea conditions. Another extremely successful method is by casting hookless plugs over the similar areas. As the fish shows interest the plug is quickly reeled in and pulled out the water as the angler places their fly in the path of the fish. Bear in mind the secret to switch-ups with Yellowfin is timing, it has to be very quick as they often loose their attraction to the teaser. As the teaser is removed it should be immediately replaced by your fly.
- Fly Rod: Quick action 12 15 weight fly rod.
- Reel & Backing: Saltwater series reel that can hold 500 or more meters of 50 – 60lbs braid. A Bimini Twist to Double Surgions should be tied into the braid, following which the fly line and backing should be joined using the loop to loop method.
- Fly Lines: 500 – 750 grain sink-tip lines with 50lbs braided loops nail knotted on both ends. Leaders: 80 – 120 lbs Fluorocarbon or Monofilament Shock.
- Knots: Fly to leader – Improved Homer Rhode or Perfection Loop. Leader to fly -Perfection loop. NB mono has a stretch factor and a tendency to slip before seating, when tying your knots make sure you leave a tag and seat them property with the use of pliers. But in saying this be extremely careful not to stress the knot.
- Flies: Poodle, Sea Habits, Mega Clousers and Flashy Profiles in blue and white or chartreuse and white or black and white tied on a Gamakatsu SL12S or SC152H in 6/0 – 8/0 (Link to fly patterns)
- Sunglasses: Dark amber or blue mirror grey lenses.
Before leaving on your trip you will be briefed in detail by the FlyCastaway guides as to exactly what fly patterns you are going to need and how you should prepare your tackle. For all our destinations we have compiled a comprehensive tackle list.