Castaway articles: Using big lures for giant flathead!

The dusky flathead has always been a popular species in Australia. Flatties are very accessible, tasty and are considered an 'everybody' fish, which is perhaps why captures, stories and photos of monster-size fish are so revered.

At full maturity, flatties are impressive creatures. Featuring a prehistoric looking head, big jaws, tough, leathery skin and impressive markings; it is not surprising big flatties were coined 'crocs'. Studying how big flathead sunbake, ambush and attack their prey adds further merit to the all-encompassing moniker, 'croc'.

I cut my teeth with lures while chasing flatties as a kid. Back then, I concentrated my effort fishing the plentiful channels and holes here on the Hastings River. I caught stacks of flatties on DOAs, Mister Twisters and Mann’s Stretch divers. While I caught plenty of 'croc-size' 80+ centimetre fish over the years this way, the average size was about 40 centimetres or so.

Quite a few years ago, I was keen to see how big flathead responded to the new wave of big largemouth bass lures from the US made popular in Australia by some 'switched on' Murray cod anglers. I wanted to test out a simple theory or observation I’ve made over the years, that: fish with big gobs eat big lures. Like other fish with big gobs that eat big lures – barra, jewies, Murray cod, kingfish and GTs – flathead are no different!

WHY GO BIG?

Flathead respond to a huge variety of lures. Some of the most prolific flattie catching lures are only 2-3 inches long. But there’s no denying big lures are incredibly effective for many trophy-size fish. It makes sense – the bigger the fish, the bigger the appetite. Big lures are also used to weed out smaller fish – a tactic utilised by many anglers the world over.

I've done a fair bit of diving in prime flathead territory in the Mid North Coast rivers and have consistently observed that big female flathead are often accompanied by several smaller male) flatties. Sometimes, there can be several fish laying on top of one another! In this situation, using a big lure might just increase the likelihood of tempting only the biggest fish to bite, leaving the pesky squeakers in their dust.

With the above in mind, it’s not surprising that a pile of big lures have proved effective for crocs on Castaway. Big glidebaits, swimbaits, XL soft plastics and even oversized surface lures are all effective at raising crocs off the bottom.

It’s important to recognise that chasing big flatties with big lures is predominantly a shallow water technique. This is because it can be difficult to fish big, lifelike presentations like glidebaits and swimbaits in current, down deep. At certain times of the year and in certain conditions, big flatties will venture onto shallow flats and lie-up. Historically, spring and summer is preferred for chasing crocs in the shallows. This time of year coincides with an increase in water temperature along with an increase in crustacean and fish activity on the flats. However, I’ve seen and caught plenty of big flatties in shallow water on Castaway in all months of the year now.

Interestingly, April through to June has been particularly productive fishing shallow areas. I’ve often hooked big flatties laying casts in shallow water where schools of spawning mullet travel over at this time of year. When a flattie is nudging a metre long, I guess it’s after a proper feed! Admittedly, the warmer days seem to be the most productive during the winter months.

LURE TALK

There’s plenty of big lures that catch flathead. They have a reputation for being aggressive feeders and small fish are often overzealous. Though, this behaviour seems to change when they’ve packed on some size. Big flatties can be painful lure eaters some days; they can shut down completely.

That said, there’s definitely lures that perform better than others in certain conditions. Over the years, I’ve narrowed our big lure arsenal down to three presentations and we'll usually use a couple of these during every session chasing crocs on Castaway.

Unweighted soft plastics
Best suited to a medium sized spin outfit. We use these lures with a 2500-3000 size spin reel with 15lb braid and 15-20lb fluorocarbon leader on a 7-7’6” spin rod rated 3-6kg. These lures are easy to use, but can take some time to rig correctly.
Glidebaits/swimbaits
Best suited to a medium tackle outfit. We use 15-20lb braid and 20lb leader on 7’6” rods rated 6-10kg. These rather peculiar lures can take a while to get used to. They have a very subtle action and you can feel very little “feedback” through the rod on the retrieve. The realistic look and action of the glidebaits seem to trigger a bite when the crocs are rather lethargic.
Topwater / surface lures
Best suited to a medium sized spin outfit. We use these lures with a 2500-3000 size spin reel with 10-15lb braid and 15-20lb fluorocarbon on a 7-7’6” spin rod rated 3-6kg. These are effective lures when fishing skinny water during low light periods or when surface activity is high.

THE BITE AND FIGHT

The bite from an 80cm+ croc in shallow water is aggressive and fast. React too slowly, and you will miss bites. A firm initial strike followed by a relatively light drag setting during the fight is critical.

Despite what some might say, big flathead will put up a decent fight in the shallows. Quite often, big fish will thrash around on the surface and occasionally jump out of the water upon hook up. It's tense and exciting stuff. Some of these big girls can get up and scream across the flats!

BIG, 'BREEDER' FLATHEAD

NSW DPI Fisheries research suggests female dusky flathead can produce about 700 eggs per gram of body weight. Interestingly, fisheries says this ratio doesn’t appear to change with body size indicating even very large female duskies remain viable breeders. Dusky flathead are known as “multiple batch spawners” and it’s believed they have the capacity to spawn up to five times annually if environmental conditions are favourable.

Using the eggs per gram of body weight ratio, an 80 centimetre fish – conservatively estimated at weighing 4 kilograms – could produce 2.8 million eggs per spawning event. Under favourable conditions, this fish could have up to five spawning events a year, which could potentially result in the production of about 14 million eggs annually!

If 0.1% of these survive year on year, this single flathead has the capacity to produce 14,000-plus flatties each year. It is clear to see why we like to take special care when releasing these big fish on Castaway!