How to Catch Mangrove Jack: a complete guide

By Bob Thornton

As the mercury begins to climb during spring in Australia’s northern half, the country’s lure casters start daydreaming about one of our most-loved estuary brawlers. Mangrove jack are a species that garner respect from anglers, and even if you don’t regularly target them, it’s hard not to appreciate these amazing fish.

Everything from their rugged but striking build, tenacious attitude, ridiculous power-to-weight ratio and tendency to tackle prey as large as themselves makes them a popular adversary. It’s no surprise that those who spend hours chasing them are often cut from the same cloth… except in human form.

These tough and determined anglers are all addicted to the challenge that comes from not only finding jacks, but wrangling them out of the twisted snag piles that these red devils call home. Good quality tools are required to extract such a fish, and Daiwa Australia have got you covered there, but before we get to that, let’s meet the mangrove jack.

Jack Lives Here

Mangrove jack, or ‘jacks’, are part of a large family called Lutjanidea, which includes other sportfish renowned for their tough demeanour such as black bass, red bass, fingermark, cubera snapper, and many more. Most of these fish are generally found over coral reefs, and while jacks spend their juvenile years in sheltered estuaries and bays, they too eventually make their way to oceanic waters.  

Growing to over a metre, this migration usually happens when the animal is about 60cm long. For estuary anglers, fish of this length are considered true trophies. Even at this size though, they demand heavy tackle, and there’s a few reasons for this.

Having a protein-rich diet, as well as a preference for large, live prey, jacks have evolved into killing machines. Their preference for structure also adds to the difficulty in extracting them. Slow motion footage of specimens in captivity shows them turning back toward their snaggy homes as they inhale their prey, meaning anglers must be on the ball to not get dusted by a jack in the first few seconds of the fight. Line breakages are common, even with heavier traces and mainlines. Their hard, toothy mouths also make short work of substandard terminal tackle, and hook straightening and even breakages are a part of jack fishing.

Tagging data has showed that juvenile jacks will often hang out in the same stretch of river for most of their juvenile life, sometimes spending years living under the same snag pile. In fact, there are multiple accounts of the tagged fish being caught several times or more in one spot over a short period.

Jacks are considered a spring and summer target, however in the more northern parts of their range where hot weather is a feature all year, they can be targeted year-round. In the southern limits of their range, they will become most active on hot, humid days with a rising barometer. Interestingly, these southern waters tend to produce more trophy size fish, while further north what they lack in size they more than make up for in numbers.

Catching Mangrove Jack

Like any sportfish, there are many ways to catch jacks, however fishing presentations tight to structure in sheltered creeks and estuaries is by far the most popular and challenging way chase these belligerent predators.

Jacks aren’t just a lure fisho’s species either; live and dead baits are known producers throughout their range. So, with that in mind, let’s first look at bait fishing options for these charismatic thugs of the estuary.

How to Catch Mangrove Jack on Bait

Don’t think for a second that bait fishing for jacks is taking the easy way out. Using bait to nail your first jack is far from the easy option and presents a challenge of its own.

The aptly-named Jack Mitchell regularly does battle with these fish in the mangrove creeks around Central Queensland, and has built an understanding of these fish through years of experience. Whether you’re using bait or lures, there are things you need to pay attention to if you want to maximise your jack hunting missions, and that’s where knowledge from other anglers is invaluable.

“I usually start chasing jacks from about now [September] and really get stuck into it around November, especially while the water is still relatively clear,” he says.

While Jack fishes with lures almost exclusively, the areas bait anglers will want to target are largely the same. And if it wasn’t clear already, mangrove jack live around structure!

Fishing baits close to sunken snags and underneath overhangs is challenging, because you want your bait to sit far away enough to not get hung up, but close enough to entice any jacks in residence.

“I like to fish the run-out tide,” Jack says, “as the water drains out, so does the bait they’re chasing, but they [the bait] will be holding up tight for as long as they can before being swept out into deeper water.

Bait anglers can use this phase of the tide to their advantage. By anchoring up current of a likely looking snag pile or overhang, baits can be drifted back, and held in front of the structure, preferably off the bottom. Structure comes in the form of timber, rock bars, mangrove forests, pontoons, bridge pylons, retaining walls, and literally anything that they can hide in and around – I’ve witnessed them living inside shopping trolleys!

When it comes to baits, live and dead baits are very both effective. As a general rule, southern anglers tend to prefer live baits, whereas up north where jacks are more numerous and competitive with one another, flesh baits and whole dead fish and squid are enough to tempt them.

Live baits can include poddy mullet, garfish, herring, legal whiting, and any other small forage species between 10-25cm long. Dead baits can be the same species, as well as filets of other species, strips of squid, prawns, and even raw steak! 

Rigging up is not complicated. The idea is to have the bait off the bottom – firstly because jacks don’t tend to hunt near the bottom, and secondly (and this applies mostly to dead baits) you want to keep your bait away from crabs, catfish, and other undesirable bottom dwellers. Rigging baits lightly and even unweighted is a good approach, and using the current to position it close to your chosen snag pile should put you in good stead.

Some anglers like to use foam floats, especially when the current slackens a little bit. Just remember that the moment that float is dragged under, there’s no time to wait before setting the hook, or applying steady pressure if using a circle hook.

Most bait rigs for jack will consist of at least 40lb monofilament or fluorocarbon trace such as Saltiga Leader and a single 1/0-4/0 suicide, circle or live bait style hook. Optional extras include a strong swivel, pea sinker, and a foam float with a toothpick or rubber stopper about a metre up from the bait itself.

The main challenge with bait fishing for jacks is getting them away from their jagged real estate, and if you’re daydreaming (or night dreaming) with your rod in a holder when a jack strikes, you’ll likely lose that fish and your rig!

Good jack anglers hold their bait rod and constantly anticipate a bite from a jack. As soon as they feel a bump, or watch their foam float disappear, the battle is on, and those first few seconds are crucial in gaining the upper hand. Reels should be kept in gear, with drag tightened ready for action.

Spin reels are perfectly fine to use, however a baitcaster or overhead set up is by far the better option if you’re serious about stopping some of the bigger models.

How to Catch Mangrove Jack on Lures

In this segment we are going to look at targeting mangrove jack by casting lures. Trolling can be extremely effective, especially down south in the canals, but we would likely run out of room if we covered both.

Casting lures is where anglers can really become addicted, and it goes without saying that accurate casting is the key to successful lure fishing. Anglers need to be a little daring to get their lures into some of the tightest country imaginable, and always be on the ball for when a jack strikes and tries to head for home.

Jack (the angler) likes to target mangrove banks with sufficient shade, always trying to get his lures as far back as possible with each cast.

“I’ll cruise along a bank, skip-casting my lures in,” Jack explains, “and I don’t stop casting.”

Skip-casting is the art of skipping your lures across the surface on the cast, and helps to get them into tight nooks and crannies where predators like jacks will sit. This skipping action not only helps the lure’s trajectory, but it also makes it look like a fleeing prawn or baitfish.

“Once I get it a metre or so away from the structure [on the retrieve], I just quickly wind it in and prepare to fire another one in somewhere else.”

“If they’re hungry, you’ll know.”

Fishing around artificial structure is a similar story, with bridge pylons, retaining walls and pontoons all prime real estate. Searching with your lures by casting them as close to these zones as possible and quickly working your way through likely areas is a great way to find them. Where possible, swimming your lures underneath objects where fish might be sitting will greatly increase your chances.

Jack also noted that the time of day doesn’t make a big difference to his results if he’s fishing around really shaded and confined habitat. More open areas may fish better in the morning, afternoon, or at night . 

A range of hardbodies, soft plastics and topwater lures will tempt these fish, and Jack has a fondness for the latter.

“I almost exclusively chase them on topwater, because it’s just such an addictive way to chase them,” he says. “I like the Bait Junkie Kikker Curlies rigged weedless, and I actually run them on a spin outfit to make skip-casting easier.”

“My frog rod is the TD Commander Longbolt with a 3000 Revelry.”

Despite having a strong preference for surface action, Jack also makes sure to have a few other outfits within easy reach. Often, a quick change in presentation can be what’s needed to bring a mangrove jack unstuck.

“I like to run a Bait Junkie 4.2 Inch Minnowrigged weedless, and generally I like a long rod for this because it makes fishing along the mangrove edge easier,” Jack explains.

“For the placcies I like the Tatulion and TD Commander Basilisk.”

Most anglers will work their presentations relatively fast when searching for jacks, and normally a hungry fish won’t hesitate to at least inspect a lure wound past them. A lot of the time, jacks are sitting within a few feet of the surface and looking up. However, there are times when a slower approach is in order, particularly on a tough day, or when the temperature has dropped a bit.

“On a separate baitcaster I’ll often have a Steez Current Master rigged up,” Jack says, “I like to have that so I have a different bait ready for if I raise a barra, or I need something that’ll suspend in their face.”

Lure casters will almost always prefer to run braided lines with monofilament or fluorocarbon leader. Mainlines such as J-Braid Grand in the 15-30lb range is great for anglers throwing soft plastics and hardbodies, however might not be enough for some of the larger jacks. Many jack devotees in southern waters (where fish are generally larger) will run 40lb braid, and even then will get dusted by better models. Do you need 40lb braid to catch a 50cm fish? You better believe it!

Getting Low

Finding good habitat is key when targeting jacks, so it makes sense to have a few areas in mind before you even put lures or baits in the water. Jack believes reconnaissance is very important, and uses his time wisely whenever he’s out on the water.

“I reckon best way to start – if you want to get serious – is to scan a creek on low tide,” he explains, “find where the snaggy banks and overhanging are, and try to imagine what they look like with more water on them.”

Areas that are high and dry during the low tide can and will have jacks in amongst them when the tide rises. Of course, sonar technology has taken huge leaps and bounds in the last few years, but nothing beats using your own eyes to ‘mark’ good spots for later on.

Once you have a few little stretches of bank stored in the memory, it’s just a matter of drifting a bait in there or firing a few casts along it.

Keep this approach up and you will eventually pull tight on a jack. After that, it’s up to you to put the pressure on and keep that fish from busting you off!