Dolphin fish, aka dollies, mahi mahi or dorado, are a pelagic gamefish found in all tropical and subtropical oceans.
They are quite amazing animals that roam the warm blue oceans constantly feeding, growing and spawning.
As a light tackle gamefish, they have few peers. They run hard, jump repeatedly, have a lot of stamina and are beautiful to look at.
They flash neon blue against the cobalt water they swim in, and their gold, green and silver blue sheen constantly switches on and off.
But these fish have one Achilles heel. Dolphin fish, unlike the mammal of the same name, are pretty dumb.
Their appetite seems to over-ride their caution. Perhaps this is because no dolphin fish is ever very old. They can grow to around eight kilos in a year – a big fish around 20 kilos in weight is probably only a few years old.
Around Australia dollies ride the ocean currents from south of Sydney in summer, and get more abundant the further north you go.
When the East Australian Current (EAC) moves south in summer they generally appear about a month before the marlin arrive, but off the Gold Coast where I live we’ve caught them out on the shelf every month of the year with the peak time being November to January.
In this area they average around eight to 10 kilos with smaller fish often aggregating around floating objects closer to shore.
Males can be distinguished from females by their blunt heads and larger size, with the female having a more rounded head.
A big male dolphin fish, known as a “bull”, will often be in the company of a number of females, called “cows”.
These fish spawn continually around current lines and feed constantly, eating a wide variety of fish and other creatures from miniscule larval fish to adult skipjack tuna.
They hunt the surface layers and rarely stray deeper than about five metres. They are so focused on the surface layers that in some Pacific Islands they are chased by small boats to the point of exhaustion whereupon they are harpooned. Amazingly, they stay on the surface throughout the entire chase.
Dollies are great eating fish, with white flesh, good flavor and excellent texture. We eat a lot of dolphin fish in my house throughout the summer months.
The key is to process them quickly. Once gaffed, these fish are one of the wildest creatures you’ll ever bring onto a boat. They can be hard to control and are actually quite dangerous.
The best way is to get a hold of the tail and bend the fish in a circle. Some people even tie them up like this. We generally clean and trunk or fillet the fish before putting it on ice.
Catching dollies
Most of our dolphin fish are caught when we’re targeting marlin, but there are a few tricks that will increase your catch rate.
Like most ocean predators, the key to catching dolphin fish is to find their food and work those areas. Dolphin fish are highly mobile and don’t hang around an area if there’s no bait.
Their phenomenal growth rate means they have to eat all the time. As such, they aren’t fussy feeders. They regularly patrol along current lines.
When the EAC moves in off the coast in summer there are often brown slicks which are often incorrectly called “coral spawn”. These slick lines are, in fact, accumulated debris where two moving bodies of water intersect.
These provide shade and food for a wide variety of small fish and invertebrates – and a lot of predators hunt in these areas.
I’ve found trolling skirted lures along current lines to be a highly effective method of catching dolphin fish. When you find them it’s not uncommon to get double and triple hookups.
The fish seem to be able to spot the lures from hundreds of metres – I’ve seen dolphin fish bounding into my lure spread from great distances.
Dolphin fish have a very risky habit of aggregating around floating objects, and almost any FAD off our coastline will attract big numbers of smaller fish.
Out at sea a floating log, trap buoy or rope is always worth looking at. I’ve seen big logs covered in barnacles wide of the continental shelf where the surrounding ocean is glistening blue from the backs of hundreds of big dolphin fish.
One of the biggest ones I ever saw, a massive fish 1.8m long and weighing 27 kilos, was caught trolling next to a floating plastic chair that probably blew off a cruise ship.
Schools of pilchards and slimy mackerel attract dolphin fish, and they are commonly caught with wahoo and marlin as they all chase the same bait.
Dolphin fish also feed on surprisingly large bait – I’ve caught them as small as 12 kilos on trolled striped tuna aimed at marlin.
It’s quite surprising how such a thin profiled fish manages to swallow a tuna but they are quite efficient at doing it and it’s common to see the remains of tuna in the stomachs of big dolphin fish.
Tackle & Tactics
Eight or 10-kilo tackle is all you need to catch dollies. Threadline gear is fun, and it pays to have a rigged bait ready to pitch as other dolphin commonly follow the hooked fish.
If you’re specifically targeting them, you can keep the leader size on your trolling lures quite light as well, with 100lb being more than adequate for any dolphin fish. They seem to hook up a lot better on single hooks than doubles.
When trolling for dollies I like a spread of five lures. From the shotgun I like something long and thin, like a small blue and gold Pakula Zipper or similar, rigged with a pair of 10/0 saltwater fly hooks (Gamakatsu SL12s are ideal).
From the outriggers I like one lumo white or green lure and a second one that is purple and pink. The little Meridian Ahis are great here.
On the short lines I like to run a slightly bigger Meridian just behind the Witch Doctor teaser. Dolphin fish definitely seem to be attracted by big mirror teasers and a lot of bites come on this lure.
The fifth lure is a Halco Laser Pro rigged with two single hooks run from the long corner position. This catches a few dolphin fish but has the advantage of attracting wahoo and keeps them from chewing up the expensive skirted lures – sometimes, anyway!
This lure also catches quite a few marlin and the hook-up rate using single hooks is quite good.
As far as lure colour is concerned, dolphin fish love bright lures with a bit of flash. Blue, silver and gold is a great dolphin attractor, and purple over pink is also good. In general, they aren’t that fussy and will eat an old trolled sock at times.
Livebaiting
When I first arrived on the Gold Coast around 30 years ago I hadn’t caught many dolphin fish and was keen to catch a big one.
Nev Howard, one of the icons of fishing in this area, gave me this advice: Catch some yellowtail or slimies, find a current line and drift along it with three baits out at different distances from the boat.
I did that and caught four big ones to 16 kilos on my first attempt. As the fish are highly mobile and swim fast along the current line, if you wait they will find you.
This method isn’t used that much anymore as anglers tend to troll livebaits or fish them deep, but it’s a highly effective and fuel efficient way to catch a lot of dolphin fish. I find choosing a nice thick oily current line with plenty of debris works best.
I find live slimies work well, and a coat of Glowbait makes them stand out even more. Floating pilchards are also good at times and are often effective when cast to fish that are following a lure hooked fish.
Trolled Baits
In southern Queensland a lot of game boats troll skipping and swimming gar for black marlin and sailfish, but trolled baits are also a great way to target dollies.
The key is to have plenty of drop back and give the fish time to get the bait down once they have knocked it from the outrigger clip.
If you watch the baits, the dolphin fish will usually light up behind the bait before striking aggressively. At times trolled baits will outfish lures by a wide margin.
Dolphin fish also respond well to trolled live slimy mackerel, skipping slimies and bonito and small tuna rigged to swim.
A combination of teasers in front of the baits make a big difference at times – these curious fish will always investigate any flash or splash.
Fighting Tactics
On eight kilo tackle a 12-kilo dolphin fish generally takes around 15 to 20 minutes to land. They are one fish that I don’t encourage inexperienced anglers to bring aboard when they are still “green”, as they can wreck a lot of gear and cause hook injuries if not properly controlled.
I like to drive forwards on the strike and let the fish take a lot of line until we clear the gear. Dolphin fish hold hooks quite well, the “jump off” rate is far less than it is with billfish.
Once the gear is cleared we motor in the same angle as the fish is heading, and then steer to close it off so boat and fish meet at a specific point.
The fish often change direction and start jumping again when they see the boat. They are a difficult fish to release but as we keep most of them for food that isn’t a problem … When the fish is close take the leader in a gloved hand and gaff the fish in the head.
Make sure you get a good “bite” as they are fairly thin and gaffs can pull through. Lift the fish on board in a single motion. As it comes over the side get a good grip on its tail wrist and bend it hard so the fish’s head is on the deck. This can be really, really interesting when you stuff it up!
There’s a spot about 2cm above and behind the centre of the eye where you can iki jime the fish. When you hit the right spot the fish will go instantly silver with pale blue dots.
If, however, you lose control of the fish, stand back and watch the chaos! There is no point trying to control a crazy fish on the deck and hook injuries commonly occur due to wildly gyrating big dolphin fish. Just wait a bit and it will settle.
Cook & Eat
These fish are a great source of many fabulous meals and should be treated with respect by being killed and iced within minutes of coming on board.
One good method to prepare a dolphin fish is to skin it before filleting. Once the fish has been spiked and killed, run a sharp knife around the edge of the fillet.
Pull the skin away from the top of the shoulder and tear back towards the tail. You can then fillet the skinned fish in four sections after cutting along the middle of the fillet above the vertebrae.
Cut out the blood lines and you will have two beautiful long fillets from each side that are easy to store. With female fish I keep the roe as well, as it’s very tasty. Bag the fillets/roe and keep on ice.
I like dolphin fish fillets cut thin and fried in Panko crumbs or left overnight in the fridge in a mix of lime juice and coconut milk with a bit of chilli.
The roe can be pan fried in flour and then cut into small sections like a sausage with chilli and garlic. It has a strong flavour that can also be blended into warm salads or as an interesting side dish.
Right now is the time to chase dollies. They are certainly one of the most exciting and beautiful fish available to Aussie game and sportfishermen. On my boat they’re always welcome – right from the hookup to the plate!
This story was first published in the Fishing World February 2014 issue.
