Mangrove Jack - Lutjanus argentimaculatus
Did you know? Mangrove Jack can be found in offshore waters as deep as 120 metres.
Sustainability and stock status
Mangrove Jack reach maturity at around about the 50cm size. However minimum size limits for keeping fish are 350mm, or 300mm in Western Australia. But thankfully this doesn't appear to have had a significant impact and Mangrove Jacks are currently a sustainable species. Mangrove Jacks also have breeding and re-stocking programs in NSW and QLD.
Check your state authorities for size and bag limits.
As the name suggests Mangroves are a common place to find this species. However Juveniles can be found in fresh water, and adults over 50cm mostly live in deeper waters offshore. This fish loves structure and is rarely found far from cover. Mangrove Jack can be encountered from the Central Coast of WA, around the tropical north, and down to about the Central Coast of NSW.
Biology, behavioural characteristics and time of year
Sizes can reach over 1 metre and 16 kilograms. Mangrove Jack are generally a maroon / red / copper colour combination. With Juveniles having white vertical stripes and electric blue lines under the eye. Most active at night they commonly prey on smaller fish and crustaceans. Mangrove Jack, as previously mentioned, don't like to go far from structure where they feel comfortable. They can be caught throughout the year, more so in the tropics, but the warmer months are regarded as their "season". Jacks can have teeth that would rival a Doberman Pinscher, so be aware when handling and de-hooking.
Fishing Gear and Techniques
Mangrove Jack are a great sports fish and a Jack attack is swift and aggressive so there's no time to day dream if you want to land one. They can be caught on bait, lures or flies; using surface lures is my personal favourite method for this species. A baitcast or spinning outfit are probably best for Mangrove Jack and the baitcast option may be the better of the two because accurate casting is important when trying to place your bait close to structure. Jacks can be caught with light or heavy gear, but medium to heavy is the best choice because you need to stop these swimming torpedoes from burying your tackle or busting your line. You also need a rod with a bit of flex, so avoid using a rod that is very stiff. But you will still need power to fight these robust red raiders. A baitcast rod of medium / heavy action and 5'10" to 6'2" in length, partnered with a low profile baitcast reel of at least 5kg maximum drag pressure should do the job. Spool up with 8 to12kg braid mainline and 15 to 20kg monofilament or fluorocarbon leader depending on where you are fishing.
Live or fresh baits are a good option. Try a lightly weighted prawn, mullet or herring with a 2/0 to 5/0 circle or suicide hook. Dawn, dusk and night time is best for this species, and as always, pay close attention to what the tide is doing. End of the run-out, start of the run-in can be a great tide period to catch Mangrove Jacks.
Killing and Cooking
An excellent table fish and highly regarded by some as the tastiest fish in the estuary. The kindest way to kill this species is by using the iki jime method.
*Photos courtesy of Dave Wilson.