Trevally’s Aren’t Easy To Catch

Trevally are a prolific and diverse worldwide species that are found mostly in tropical waters. They fill a wide range of habitats, many of them overlapping. Because of the nature of its continental coastline Australia has the most diverse range of trevally on the planet, from monstrous GTs, to fish that are barely recognizable as a “trevally”, and that’ll have you searching through books and scratching your head to identify. There are some 32 different species here that can be caught on fly.

The Golden Trevally

Unquestionably Giant Trevally ((Caranx Ignobilis) and henceforth referred to as GTs) are the baddies of the trevally world. They have an immense reputation among all fishermen, and rightly so. They are the undisputed heavyweight champions, thugs, brutes, and beasts that fishermen go to huge lengths to engage with, and hopefully to beat, especially on fly tackle.  

GTs are a deep bodied, broad sided fish that grows to well in excess of 100lbs. Like all trevally they inhabit a very wide range of waters. This is a common theme among all these trevally species, they are often just where you find them, but they are almost always near some kind of structure.

GTs are relatively predictable however, they like places where there’s a concentration of current, what we refer to as a pressure point. It’s a pretty simple equation that appears everywhere in the natural world in many different forms. The current feeds the bait fish, and those baitfish feed the GTs. The bait most guides and anglers look for on these points are a variety of fusiliers, and also garfish.

If there’s enough food to warrant them going there, GTs also get into the shallows to feed and will move into water on the flats that’s just deep enough to cover their backs there. Schools of mullet, garfish and squid are great favourites. They can maraud across a flat like a gang of thugs cutting a swath through a shopping mall, and at times, if there’s enough current, they’ll also take up station behind lumps of coral and just hold in ambush.

Types of GT Fishing

There are broadly two types of GT fishing, one involves the guide making very long casts with a large hookless popper at the sort of places GTs hold up. The fly fisher waits for a fish to smash the popper then makes a long cast to intercept the incoming popper (and fish). The teaser man rips the teaser from the water when the fish reaches the fly, and with the only thing left in the water being the fly, its game on!!!!

The other method is to sight fish for them on the flats, and this is the preferred method for most fly fishers. For this you need good local knowledge and to stay focused. These are a fish you need to specifically target with tackle, flies, leaders, and techniques. If you are in GT water you always want to have a dedicated 11-12 weight rod rigged and ready to go with a minimum 60lb leader, a 6/0 brush fly and at least 50 feet of line stripped off ready to cast in some sort of line management devise. They move quickly across the flats, but are also usually big enough to see from a long way off. Random encounters with light tackle will rarely end in the angler’s favour.

Tropical North Queensland GT

However the northern tropical waters of Australia are home to more trevally species than any other place on earth, not just GTs. If you are at all interested in catching new species that can have you digging around in fish identification books, then these are the waters for you. If you’re also interested in getting involved in some battles with straightforward, no nonsense aggressive and pugnacious fish, then you’ll get your fill here as well.

All the other trevally come in many different shapes, sizes, and ways of behaving, and this makes them always interesting. And they can turn up almost anywhere; you can find them cruising the flats or tucked in behind a snag in a mangrove creek, or busting into baitfish schools on the surface like tuna, or over deeper reefs where they can be brought to the surface to within fly range, or alternatively you can sink flies down to them. You’ll find them on the deep blue oceanic waters of the outer Great Barrier reef, and over any area of shallow inshore reef right around the tropics. They can be so prolific, so aggressive and pugnacious, that experienced local anglers will drive away from them after a couple of fish.

Brassy Trevally Are Not GTs

Brassy trevally (Caranx papuensis) are often confused with GTs. They certainly don’t grow as large but are every bit as pugnacious. Their bodies are more elongated than a GT and their anal and dorsal fins are usually yellowish but always with white tips. They’re a fish associated with shallow inshore reefs and good current flow. They hang in large packs, especially the middle sized fish in the 10-20lb range, the bigger the fish (up to 30lbs) generally the smaller the school.

Their favored haunts are around inshore reefs where they ambush bait coming onto the reef with the tidal flow. They particularly like wrecks and stopping them from making it back to the rusty superstructure requires some luck and a lot of skill. They also like to hold around creek mouths on the incoming tide as baitfish are swept in with the flow. There’s not a lot of subtlety about these fish, they are highly competitive and aggressive.

A good session in an area with a lot of them will probably see the angler eventually whipping the fly away from them – they can beat you up as well. You don’t want to get caught under gunned in a fight with a brassy trevally, their pretty much one dimensional tactics mean you have to stop them getting to the reef, and then you have to beat their broad sided body which they use to great advantage. Knowing how to fight a fish well on a fly rod is a great asset and these fish are brutal teachers if you don’t. They eat most flies that are put in front of them and particularly like poppers.

Diamond Trevally

Diamond trevally (Alectis indica) are an unusual looking fish that seem to turn up unexpectedly in all sorts of places. They have deep bodies, but are thin through, and are a beautiful shimmering reflective pearlescent silver all over. In the smaller fish the dorsal and anal fins have long trailing pennants. Diamonds are never in the sort of large schools you usually find other trevally species in, they are a much more singular species.

The best diamond trevally fishing is usually off the backs of big stingrays, which they love to cruise with on the flats. They show up as not much more than a shimmering blue blob on the back of a stingray.  Crab flies and other crustacean patterns sunk anywhere near the ray are rarely refused. They use their deep body side on in the water and like all trevally you have to earn the right to hold them.

Bludger Trevally

Bludger trevally (Carangoides gymnostethus) are a deeper more open water species that often school up on the surface feeding like tuna. They don’t grow large, 10 kilos would be a very big bludger, but they are rated pound for pound as probably the hardest fighting of all the trevallies. Bludgers are more torpedo shaped than other trevally, they have elongated streamlined bodies that are built for speed. They eat the same sort of flies you would cast to tuna but are also very partial to surface flies.

Golden Spot Trevally

Gold Spot trevally, aka turrum, (Carangoides fulvoguttatus) are not to be confused with golden trevally.  Another shallow water species of trevally usually associated with reef structure, and especially shallower reef passages, they also get up onto the flats to feed.  Some years ago, on a search for bonefish on some northern Great Barrier Reef flats, on a perfect early morning incoming tide, we encountered schools of spikey tailed fish pushing in with the tide and feeding hard in the substrate; they turned out to be tailing gold spot trevally. On the flats, and of a reasonable size, they’re usually single, or in pairs. Their preference is for baitfish patterns rather than crustacean flies.

What You Need to Catch Trevally

All of these trevally (and others) can be encountered in a very wide range of sizes right across Australia’s north. In estuaries little hand sized trevally can haunt all the best snags in huge numbers and can become a pest when you’re fishing for barramundi – then not far offshore the same species can be there in similar numbers but are now an arm’s length long.

If you target them specifically, especially in the larger sizes outside the estuaries then you are going to need solid tackle. #9 and #10 weight rods and reels with a very robust drag system are pretty much standard gear for most of the fish encountered in Australia’s inshore tropical waters, and these will suit most trevally fishing just fine. The GTs will require some serious upgrades. If you want to specifically chase GTs  (they are not everywhere in decent numbers and in many places they just suddenly turn up) more specific location research and specialized guides are required.

This article was written by renowned Australian fly fishing guide Peter Morse for Tourism Australia and shared with Karen at Visit Australia on Vacation to publish.