North Australian FISH FINDER TM forums

Anyone who says there aren't many mangrove jacks around Darwin is probably just keeping secrets.
True, jacks do like sandy waterways rather than muddy ones, unlike barramundi which love turbid water, and our harbour is mostly mud with some sandy banks.
Darwin Harbour does not have any really sandy creeks, except for a couple of little ones near Mandorah, but the harbour still has plenty of jacks if you know where to look.
On my last fishing trip I saw plenty off the headlands near Mandorah - schools of five or six fish at a time to be precise.
They were fairly hungry too, although jacks are usually a bit fickle about taking lures, and it's better to target them with fresh bait or live bait.
I found the secret to finding them is to fish the rising tide, casting hard up against the rocks.
I let most jacks go because I believe they are vulnerable to overfishing.
Keeping one or two fish should do no damage.
Jacks do turn up in other places, but the Mandorah rocks are possibly the best Darwin spot.

Been a bit quiet with reports so I will bump some old posts that may be of interest, such as this one, from 2005, still a relevant topic, feel free to comment.

Seen a few caught down at a local pontoon lately where its all mud. On the bottom at least.

Last week a couple caught a 56cm on a bit of pilchard.