Jack Basics

[Didley]

There have been a few requests for Mangrove Jack info of late, so I thought I put finger to keyboard and see if I can help a few Active Anglers who are starting out with these magnificent fish. I’m not going to give any “secrets” or locations away here as I value my life and jack fishermen including me, don’t give up hard earned knowledge with out a fight. I’m not claiming to be an expert, far from it in fact, getting there means a lot of time on the water, I live in Brisbane and need to travel to fish, so I don’t get out enough to get good at it, if I get to fish once a week I’m doing well, and that’s not enough. Although these fish are not rare, in the sense that they are being wiped out, they are not around in the numbers that our bread and butter species like flathead, bream and whiting are, and being SEQ’s premier sportsfishing target (IMHO), they deserve a little special attention. I’d encourage any one targeting them to practice catch and release and look after them when removing them from the water, i.e. use newer “soft’ style landing nets and if your using “lip gripers”, support the fish under the body when lifting it and minimise the time out of the water. If most of us do what we think is right, we’ll continue to have a great fishery into the future. If you want to try their eating quality wait till you gut hook one or know you’ve done some damage reducing it’s survival chances.

Mangrove Jacks (lutjanus argentimaculatus) belong to the lutjanids family, to which fingermark, red emperor, coral trout and moses perch belong. If you want to read up on some of the more technical info on MJ, I can recommend this site which contains some fascinating information http://www2.dpi.qld.gov.au/far/9229.html. There are a variety of other names for mangrove jacks, like Dog bream, Red bream, Mangrove red snapper ect. Like all of there family, Mangrove Jack possess a top of the line set of dentures jackjaws.jpgand should be treated with great caution. They can protrude their jaw forward and snap at lightning speed, so keep your fingers well away from there mouth and use a pair of long nosed pliers to remove hooks. When fishing at night, in an area containing MJ you’ll often hear a popping noise, usually in the shallows, which is the jacks smashing bait off the surface with this lightning snapping motion. This is a great sign as you know they are there and feeding and you’re in for some action.

The colour of mj vary between nearly bream silver,dcp_2167.jpg through red 22.12 004.jpgto olive brown depending on the location they’ve come out of and their mood. Smaller fish have blue lines around the eyes and snout. You’ll also find they change colour from the time they come out of the water to release; this is aggression, anger, or fear. People with pet a mangrove jack in fish tanks will describe the changes in colour at feeding time ect. Jacks taken from fresh water reaches tend to be darker also.

Size is interesting, in southern Qld open estuaries, 50 cm is a good fish (58 is my PB at the moment), 60 is very rare, and 70 is spoken of a few times a year. The reason I say open estuaries is, extra large fish are often reported, but many of these are caught in impoundments, lakes, billabong type areas that are closed off from the ocean, preventing the fish from going off shore when they reach sexual maturity, therefore they can get quite a bit larger than the would if allowed to migrate naturally. So when they are stocked in dams like Awoonga near Gladstone or Tinaroo, as they are they’ll grow to huge proportions. My understanding is the upper size limit of north Qld estuary Mangrove Jacks tend to be smaller and the further south you go the larger they get. 40cm is a good MJ up north, high 40s-50 at Noosa, 50cm around Brisbane, 55- 60 Tweed Heads, and 60-65 Coffs Harbour. This is due to growth rates and moving off shore at a given age ie. a southern fish will grow faster and therefore be larger at a given age when it leaves the estuary, if you get my drift. A Mangrove jack can reach 40 years of age.

There is some evidence to suggest that MJ that leave the estuary never return, if that is correct, it follows that the fish are present in the estuaries year round and just dormant during the colder months, but I’ll wait for more science on that one. What we do know is the time to fish for them is summer, the hotter the better. Water temp of above 20 degrees C, nicer above 25, great in the high 20’s. Nice humid days, with afternoon storms are great. Barometric pressure is controversial, but a rapidly changing reading, one way or the other seems to do the trick (approaching storms).

Location; the number one rule of jack fishing is structure, be it rocks, fallen trees, jetties and bridge pylons, jacks live, work and play around structure. If you don’t have it, your chances of getting a Mangrove Jack are very low. Cod are a common by-catch for this reason.cod 002.jpg Good cover that falls into deep water is best. Rocks are my preference, large rocks, they create large holes for fish to hide in, smaller rocks only give rough texture to the bottom, OK, but big caves and crevices are the go. Big chunks of coffee rock or slabs of concrete are great. They are ambush feeders and tend to wait for a feed to come to them, dart out, turn, smash the bait fish and are back in their hole before you can blink. When waiting for their next victim jack will sit positioned in the back eddy behind the structure, saving energy for the next feed. So low tide is a great time to prospect for likely locations, find back eddies around fallen trees or rocks that’ll be deeper and invisible at high tide, and come back later on. Current keeps the food coming so a good strong current can be another useful thing in the creation of a prime jack location. Overhanging banks on the bends in estuaries, where the water flow has undercut the bank creating shelter are terrific, the fish sit under there out of the light; moored boats are another target area. A canal entrance, right on the corner is a top spot, under those floating pontoons too. Drains or small creeks where water containing small bait fish is entering a larger creek or river is another great location for Mr. Jack to lie in wait for a feed, so give them a flogging with your lure. My fishing is done in SE Queensland, Tweed heads to Noosa, the whole area is filled with canals with bridges, particularly the Gold Coast, prime Mangrove Jack country. Where it’s not so developed, there are creeks with fallen trees, that’s lure heaven, get out there.

Time; The time to go jacking is any time you haven’t got something more pressing to be done, time on the water is what catches fish. As mentioned before up coming storms, changes in light conditions i.e. dawn and dusk seems to be a prime time. I find different locations fire at different tides, but an hour either side of low tide is what I’ve found to be peck time, generally speaking. Jacks have large eyes for good reason, they go hunting at night. If you find a good baiting spot fish long periods whether your getting fish or not , over time you’ll find the fish will “come on” and off as schools move in and out. Over time you’ll notice there are peck times for your spot based on tide rather than time and you can target these tides, coordinating with the time you want to fish i.e. I’ll look for a low tide, at say 10pm, to fish one spot of mine, gives me good fishing from 8.30ish to 11pm home by 12, another spot high tide 8.30pm good fishing 9pm till 11pm, home by 12. Only time on the water will get that sorted for you. So let’s summarise time a little, late afternoon a storm approaching, good time to flick a few lures round some fallen trees and rock walls, 4am start, again lure flickin time. Middle of the day, jig some prawn stars or soft plastics around in deeper holes where the fish are hiding from the light. Dark of the night, live baits along rock walls, rock bars, bridge pylons.

Bait; Live poddy mullet and herring are the most common, but most small fish will do the job, try and match what they are feeding on in the area your fishing. Live prawns are said to be the best Mangrove Jack bait there is, by some, but if I could get a good supply of them the jacks wouldn’t be seeing them. Size wise, anything between about 8cm and 20cm, the larger ones, you’d think, for the big boys, but you’d be amazed what a small jack will clobber. Crabs are a favoured food and can be a good bait to throw onto a jetty and drag it slowly off, the jacks sitting under think, ah here’s a crab dropped off the jetty, smash! You gotta think like a Jack. I put a 4/0 just under the skin, just behind the head. Some blokes like to put a stinger hook also, up near the tail, maybe even a treble. Not a bad Idea if you’re using a larger size bait.

Livies are great, but not everything, a well presented fresh dead bait will out fish a livie more often than people think. I like to butterfly a freshly dead mullet or herring, opening up the flaps to the gut cavity to get the juices flowing, creating its own burley trail.dcp_2202.jpgdcp_2203.jpg
Lures;dcp_2210.jpg I’m a bit of a believer in the whole lures catching fisherman thing, a lure might be a lure, but in saying that I like the “Tilson Barra” it does every thing right straight out of the packet, swims well, looks right, has strong hooks and split rings. Some imported lures or cheapies will need up grades to the terminals to hold up to jacks, but any thing in that 10-15cm size range is the go.

Colour, I like gold, red because jacks are territorial and like to keep small jacks out of their territory, so they say, and silver to imitate mullet and herring. Colours are all about catching fishermen too. That’s why 80% of the time I’ll have a “Tilson barra” in “Jaffa” colour on my baitcaster, I’ve had good success with it so I’m convinced it makes a difference, but I might be wrong.

Jacking tackle; Lure casting, you can’t go past a good baitcaster set up. Rod of 6-8 kg graphite is great, but I used a good quality glass rod to good effect for a long time. You’ll need a baitcaster to get the accuracy required to get those lures within about 30cm of where you want them. Reel, go quality, it’ll last a long time and give you no trouble, Shimano or Daiwa, I use Shimano Calcuttas with improved drags, they do the job and have been going for about 10 years. Line, 20lb braid, any less and your sporting, any more its over kill. Leader, 40lb mono I use Black Magic “Tough trace” or Jinkai or FC Rock Fluorocarbon about a metre to a metre and a half long.

Bait fishing, same rod or a spinning outfit of good quality, I use a Shimano Stradic 4000 with a 6-8kg rod, 20lb Braid but up the leader size to 60lb or if you’re expecting trouble 80lb. Knots wise, there are plenty of knots to do the different jobs, get a good knot book (Wilson’s), figure out a good one for the job and use it. As you have failures replace that knot with a better one and you’ll end up bullet proof. I started with a spider hitch to get a double and found the line was breaking there under extreme load (snags usually), so put the effort into learning the Bimini twist, then I was straightening hooks, so heavier hooks ( Black Magic). Now I can pull a Russian submarine up. I don’t use a swivel, it’s just another lump to snag up on rocks, and you don’t get the twist problems with braid you get with monofilament. So a good 20lb braid, doubled in the last metre or so 1-1.5 metre 60lb leader, straight to a strong 4/0 with a small pea sized sinker right on the hook. Sometimes I’ll use a float with a small light stick in it, to ease a live bait back to a snag, so I can see its exact location, hook just behind the head of a livie and you’re in business. Trolling and jigging I can use either, but usually the spinning outfit due to the longer rod and good drag.

As with most fishing keep things very quite, don’t drop sinkers on the hull, rods on the gunnels ect. Sharp noises will shut things down, real quick. Anchor chain scraping over the side of the boat is another bad mistake, it’s worth putting a bit of old bike tube over the chain to dull things down. A bow mount electric is invaluable obviously when luring , moving between snags, but also I like to use the electric to move in on a bait fishing spot , the last 50 metres or so other wise you’ve got to wait 30-40 minutes before you’ve got the place settled down. Keep lights off the water, even turn the sounder off, and keep things as natural as is possible.

It’s often said when fishing for jacks; it’s all won or lost in the first 3 seconds. Lure fishing into snags, I’d agree pretty much with that, if you get it a 2 meters out of the tree you’ve got him 90% of the time. But livie fishing in tough country, you haven’t got him, till he’s in the net. Gold fish might have 7 second memory’s but jack’s are smart fish and if you win on one snag they rip off in another direction to another snag. The biggest fish I’ve ever “nearly got” on lure was like this, smashed me on a fallen tree, knees were like jelly, and I got him out by two meters and thought “unreal”, a big smile came to my face, then with in a second, he’d gone sideways in a blistering run and had my lure wedged firmly in another snag 3-4 meters up the river and out near my boat. “What the”. Never saw that lure again.

Often when fishing with newbies, my nerves are tested when the sit their rod across their lap or on the seat to grab a smoke or something to eat. Always hang on to your rod or put it in a good strong rod holder, if a jack takes that second to smash your bait, your rod and the fish will be gone, over the side, never to be seen again.


So number one rule STRUCTURE . You want more fish, TIME ON THE WATER Good luck and look after our red fish, they are special.

[tailorboi99]

Awesome job Didley. Thanks for all this information.

Tom

[Didley]

Sorry screwed up with the photos there
Dids

[Two Utes]

Thanks for taking the time to write up such a comprehensive report on Jacks and how to target them. They sure look like a tough candidate, especially with those dentures, large fins, and lots of power in that large tail fin.
I hope that l get a chance to target them one day.
Thanks again for the lesson.

[Hungy]

great post thanks alot

[booker]

great write up, thanks for taking the time to share that info with all of us.

[Pistol_P]

Great stuff dids,

Mate that is great info for all the jack hunters.
To effort in writing all that up mate....Thats what makes these site so good.

Cheers
Pete

[Talina]

Thats awesome Didley...Thanks heaps for taking the time out to do the report!!

I noticed & would have to agree with you on the lure colour!! I have been very successful chasing Jacks on the red/gold coloured lures!!

[Shortlite]

Great post Didley, and spot on with some of the info. Gold is one of those high flash colours that just seems to draw a lot of attention, but the trick with red is just what you explained, and a bit more. Territorial, but also cannibalistic. Baby jacks are toothy spikey candy to a lot of fish.

[Didley]

A little constructive criticism, is very welcome here or additional info. As I said I'm no master of jacks, I'd like to learn something too.