Category: High Risk
THE sight of a big giant trevally's shoulders pushing heaps of water aside in hot pursuit of a surface popper is an instant adrenalin rush for most sportfishers. Some people say that poppers where made for GTs, as they are most frequently called by the anglers who pursue them. And they could well be right.
GTs come in a range of sizes but it's the big ones that get anglers fired up. And it's not just their weight it's the added dimension you often get when fishing for GTs. For example, they inhabit extremely challenging country such as sharp, coral covered bommies in shallow water one of the toughest environments from which to extract one of the toughest fish in the sea. GTs are the largest and most aggressive of the trevallies and probably one of the fiercest fish predators. They move swiftly from reef to reef, sometimes hunting in very shallow water. They feed mostly on fish, but also heaps of water aside in hot pursuit of a surface popper is an instant adrenalin rush for most sportfishers.
I recall on one occasion we sighted a small school of GTs ranging up to 30 kilos, took the hooks off our wooden poppers and allowed the fish to shred every bit of paint off the lures as we whooped and hollered like a pair of 12-yearolds. Yes, a good GT session can do that to a man. Older anglers may recall the name lowly trevally, which is what the giant trevally was commonly called before being renamed. GTs are not a favoured eating fish so the vast majority get put back to grow even bigger. I like that.
Adult GTs are generally easy to identify but juveniles up to three or four kilos are a bit more challenging, given that there are just so many different trevallies in the ocean. The bigeye is probably most frequently confused with the GT but it has a much bigger eye, as its name suggests. The GT also has a steep forehead profile.
Western Australia has its fair share of really big GTs inhabiting the inshore waters from Exmouth to Broome and offshore at Rowley Shoals. The biggest GT on state game fishing records is a bruiser of 39.8kg taken by no less than former saloon car champion, Peter Brock. In fishing terms probably any CT over 10 kilos is a good fish and over 20 kilos is a monster, and there are quite a few monsters caught in our northern waters. For many years the largest GT on record for Australia was a 52.5kg fish speared in Shark Bay (no length was provided) and South African records list an angling capture weighing 55.3 kg, So they do grow big and bad.
No major threats have been identified, other than local stock depletions as a result of heavy recreational fishing.
Tackle and bait
Anglers targeting GTs generally either troll or cast lures. Trolling outfits should be selected to suit the size of the biggest GT you're likely to encounter in the waters you're fishing. And whereas 10kg may be fine in deep, "friendly" trolling country, 24kg may not be heavy enough in shallow, bommie-strewn territory. When casting poppers 1 generally fish 10kg, but if I'm in pursuit of a horse GT 1 will use braid, with a mono trace, For this job you need a rugged spin stick that can put the brakes on quickly and not end up snapping like a carrot. 1 favour conventional proven rod styles, combined with a Penn 850, for such brutal fishing.
Most text books list the southern extent of distribution as Rottnest but very few turn up that far south. Even the wonderful coral bommie habitat of the Abrolhos Islands attracts just a few GTs. It's around Dirk Hartog Island and Shark Bay that reasonable numbers start showing up.
Breeding and migration
Not much work has been undertaken into the habits of GTs but breeding occurs during summer, and young fish are often found in estuaries. Young adults are common in inshore turbid waters of the Dampier Archipelago and the Kimberley. Sexual maturity occurs at a fork length of about 60cm and about three years old. Males are more numerous than females and are slightly darker in colour.
The type of country that might hold some jumbo tailor down south is likely to turn up a GT up north. White water washing over the top of a lump, with shallow broken country all around, just screams GTs, and it's here that poppers really come into their own. The last thing you want to do in this sort of country is to cast out a lure and have it sink, or dive, into the reef and coral. So a floating popper is the obvious practical choice. Of the different types of poppers around these days, the three that have worked best for me over the years are the cup?faced wooden ones which skip and slurp all the way back to the rod tip. Varying retrieve rates are integral to this style of fishing.
The clear resin poppers such as Hawaiian pillie poppers or local Redbacks are best fished with variation in rod tip height and retrieve rates. I have had some really good sessions on these types of lures. Probably the most internationally popular popper style for GTs is the blooper. This bulbous, cup-faced popper is twitched, stop-start fashion, and frequently GTs will hit it as it sits motionless on the surface. The larger bloopers can really benefit from a savage downward rod tip action to "bloop" the bigger fish into your area. This is great fun, but don't forget to crush down the barbs to save both you and the fish from excessive damage. Some anglers target big GTs by trolling rigged mullet or garfish baits around dropoffs. Very slow trolling or mooching as 1 tend to call it with large weighted swimming baits can produce GTs, and also a very welcome bycatch of big mackerel.
References: Allan & Swainston, The Marine Fishes of North Western Australia. Compiled with the assistance of Dr. Barry Hutchins Curator of Fishes, West Australian Museum.