Not good news ABF, you need to give the Brisbane River a good break, maybe 4 + weeks, if we don't get anymore rain, after good rain all but the vermin make their way down to the mouth of the rivers and creeks to get a bit of salinity in the water. You need locations that are getting a good tidal flush of salt water twice a day, maybe get your Dad to take you to Bribie if he has the time and fish maybe Woody Bay or Red Beach, both areas get a good flush every day regardless of the rain, if you and Dad like camping on the beach, make a trip of it and take a small tent, couple of sleeping bags and get some jaffles cooking over the coals, after reading this Mangajack might even cook em for ya, good areas for flathead, dart and whiting, be a bit of an adventure hey!
Good fishing to you
fatboy