Costa Rica Yellowfin Tuna Fishing on Dolphin Schools

Costa Rica yellowfin tuna fishing runs on dolphin schools. Off Golfito and the Osa Peninsula, yellowfin travel with white belly porpoise, spinner dolphins and spotted dolphins, and each species tends to hold a different size of fish. The tuna usually sit out in front of the pod, so the pass you make with the boat decides the day more than the bait you throw.

We filmed this fishery with Mike Hennessy of Colio Sportfishing out of Golfito, and on one of those days I was the one on the rod, fighting a yellowfin off a spotted dolphin school on a sailfish outfit with 12 lb of drag. Hennessy has a decision rule for each of the three cetaceans, and this page lays them out.

For the species basics, start with our yellowfin tuna fishing tips for offshore anglers, then come back here for the dolphin-school version.

Why do yellowfin tuna travel with dolphins?

The association between yellowfin and dolphins is well documented across the eastern tropical Pacific. Both feed on the same bait, the tuna push it toward the surface while the dolphins and seabirds work it from above, and commercial purse seiners have used the pairing for decades to find tuna.

Hennessy's working picture is specific. The dolphins locate the bait by sonar, which off Golfito is usually a small black anchovy, and track onto it. The tuna sit slightly in front of the pod and down about 100 to 200 ft, and they push the bait up. That is why he tells his anglers to read the birds, not the dolphins. The birds dive on the tuna that are in front of the pod.

The purse seiners matter here in two ways. They have been moved out to 100 miles, which Hennessy credits with helping the tuna across Central America. But these schools were seined for years, and they are boat-shy because of it.

Farther offshore, the Costa Rica Dome adds to the region's productivity. NOAA's Southwest Fisheries Science Center describes the Dome as a regional center of high productivity in the eastern tropical Pacific, with higher plankton biomass that supports prey for dolphins and other predators.

When is the best time to catch yellowfin tuna in Costa Rica?

In Costa Rica's southern zone, yellowfin are available most of the year rather than in one short season. Numbers build steadily through March, fish stay available from May through August, and in December yellowfin, roosterfish, wahoo and cubera snapper can all be targeted in the same week.

Out of Golfito, the run to the offshore structure is one to one and a half hours, and the surface bite with poppers and stickbaits comes when conditions push the tuna up and they are eating aggressively. Our month-by-month fishing calendar for Costa Rica's southern zone covers the rest of the year by species.

Hennessy's caution is that patterns change day to day, so the school you find tells you more than the month does.

Which dolphin school holds the biggest yellowfin?

Ask the captains on Costa Rica's Pacific coast and most will tell you spotted dolphins. White belly porpoise, spinner dolphins and spotted dolphins all carry yellowfin, but each species moves differently and tends to hold a different size of fish, so the approach and the tackle change with the school you find.

Spotted dolphins usually carry the fish between 100 and 300 lb. Spinners are Hennessy's favorite school to fish, because they track so well, but they hold everything from 30 to 200 lb.

How do you fish white belly porpoise for yellowfin?

White belly porpoise travel in a long, loose line and change direction often, so the usual approach is to find the part of the school with birds and surface activity, get well ahead of it, and drop live baits in its path. Patience on the approach matters more than speed, because a rushed pass pushes the fish down.

Hennessy describes a white belly school as an army moving forward, up to five miles wide. He works only the section with birds in front of it and tuna popping, gets about 100 yards ahead, and tosses baits when that group is about 100 ft away. A butt-hooked bait swims down on a slow school; a nose-hooked bait lets him reposition fast. Never come in from behind. If it takes 20 minutes to line up a clean pass, take the 20 minutes.

When live bait only produces 10 to 20 lb fish, he trolls ballyhoo under a blue and white or purple and black sea witch at four to five knots, and as slow as three when he is marking fish. There is no need for marlin speed.

How do you fish spinner dolphin schools with live bait and poppers?

Spinner dolphins travel in tight, straight-line schools, which makes them the easiest dolphin to position on. The standard play is to get in front of the school's path, stop, and present live baits or cast poppers as the pod comes toward the boat, keeping well clear of running over it.

Hennessy's trick is to get the pod comfortable with the boat first. He tracks out to the side until the dolphins accept the boat, then moves in front and sets up a pass that brings them toward him, throwing when the birds dive on the tuna ahead of the pod. He starts on 80 lb fluorocarbon, because a spinner school can hold 150 and 200 lb fish, and steps down to 60 or 40 lb only if the bites come from 30 lb fish.

On the popper, they eat on the pause. Yellowfin have hard mouths, so he jams on the fish two or three times, then lets it run against 15 to 18 lb of preset drag. When they ignore the popper, a stickbait wiggled lightly across the top still gets bit. Run the school over and the big tuna go down, leaving you with 10 lb fish.

How do you catch big yellowfin on spotted dolphins?

Spotted dolphins travel in smaller groups than spinners or white bellies and are the school most associated with trophy yellowfin. Captains fish them with the biggest live baits on the boat and heavy fluorocarbon, positioned well ahead of the pod so the bait is already swimming when the school arrives.

Hennessy drops big live skipjack or frigate mackerel, the kind of bait you would put out for a marlin, on 150 lb fluorocarbon and a 9/0 circle. He lets the bait back about 150 ft, holds it there with the reel in free spool and the clicker on, and when the fish eats, lets it run to a count of six before coming tight.

The dock talk from that trip is the most useful thing I have heard about big-bait tuna fishing. Fish around 100 lb will T-bone a big skipjack and never swallow it; it takes fish over 200 lb to eat one. They will not eat a bait that has already been bitten, so change it. And when the pod is spread out and the tuna bounce from group to group, slow troll the live skipjack in front of it until it tightens up, because a tight group with birds over it bites immediately.

The fish I fought that day did not eat the skipjack at all. It ate a ballyhoo on a sailfish outfit, 50 lb line and 80 lb leader, with 12 lb of drag, and it took a long stretch of light, steady pressure with the rod only halfway up to land a yellowfin of about 80 lb. That is how it goes in sport fishing: put out the light line, and that is the one that gets bit.

How do you approach a dolphin school without spooking it?

Slow down and get ahead of it. The standard advice is to approach from the side or front at low speed, keep engine noise down, and position the boat where the school will come to you rather than chasing it, since running at a pod scatters the dolphins and sends the tuna deep.

Hennessy comes in really slow, because these schools are boat-shy, and never from behind. He would rather spend 20 minutes going wide than come in hot and have the dolphins turn and pull the tuna away. On a spinner school the first pass is always tough, because you do not know which way they want to track yet.

Where the common advice breaks

You will find precise distances published for each species, such as 200 to 300 yards ahead of spinners and 300 to 400 yards ahead of spotted dolphins. Hennessy does not fish by fixed yardage. The only number he gives is about 100 yards ahead of a white belly line, with baits going in when the group is about 100 ft away. For spinners and spotted dolphins his instruction is simply to get well out in front of them and let the pass come to you, however long it takes.

What works when you run out of live bait?

When live bait runs short, dolphin-school anglers switch to trolled rigged ballyhoo, skirted lures, poppers and stickbaits, or speed jigs dropped ahead of the school. The choice depends on what the tuna are doing: feeding on top, following the pod down deep, or not showing at all.

Off Golfito, Hennessy rigs eight different live baits, goggle eyes, threadfin, sardines and small ladyfish among them, on one 7/0 circle. Short on bait, he runs a sea witch over a ballyhoo: blue and white imitates a flying fish, which the 50 to 60 lb fish were eating when we filmed, and purple and black looks like a small skipjack or bullet mackerel.

When the fish are popping, poppers and stickbaits take 60 to 80 lb yellowfin, and he carries both because some days the tuna only eat one. When neither works, he trolls bibbed lures.

When the dolphins are pushing bait but no tuna show on top, speed jigs fill the gap. Get about a quarter mile ahead of the pod, drop 180 to 250 g jigs to 200 to 250 ft, and work them on the windward side of the boat so the line stays clear of the hull. Our jigs for yellowfin tuna fishing video covers the retrieve.

Fighting yellowfin off a dolphin school

A yellowfin hooked off a dolphin school will dump 100 to 200 yards on the first run and feel like it will never stop. It will. Let it run against the preset drag, then slow grind it back with low, short half pumps.

Instead of circling the fish, Hennessy puts the wind in the angler's face with the fish off the side, so the boat drifts away from it at about the speed it circles. For the last 30 ft the rod comes out of the holder and goes under the angler's armpit.

At the gaff he differs from the Venice captains. Where Josh Howard prefers a belly shot, Hennessy wants a head shot, and only once the head is out of the water and the fish is on the surface. Gaff a yellowfin deep and it can take the gaff, and the rod, away from you.

Questions About Costa Rica Yellowfin on Dolphin Schools

Making the Right Pass on a Costa Rica Dolphin School

The dolphin-school fishery on Costa Rica's southern Pacific coast is a fishery of decisions. Which species is this, where are the birds working, which way is it tracking, and how long will you wait for the right pass? Get those right and the tackle is the easy part.

The rest of the library covers the same fish on trawlers, birds and bait balls in other fisheries, and you can browse every one of our yellowfin tuna fishing videos by technique.

For a fishery that runs on structure instead of dolphins, our article on Venice, Louisiana yellowfin tuna fishing on trawlers and rigs shows how different the same species fishes in the Gulf of Mexico.

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