IMO , the Queensland State Government missed an opportunity when the Traverston Dam project got rejected by the Feds. They had already spent $600million buying properties which were to be affected by the proposed dam's footprint. Turning that land into national parks and rehabilitating the river banks after years of poor farming practices (eg. cattle trodden river banks, etc..) would have been awesome but required more money to be spent.
Instead , the state gov has been slowly dripping feeding those lands back into the market place and/or leasing them back to graziers. Until the banks of the Mary River are stabilised and associated erosion is sorted out, the river will continue to be a silted up warm wide stream. Its natural default state is a cold stream running through a closed canopy. Species like the Mary River Cod are dependant on those conditions.
While talking fish , the recent arrival of Sooty Grunter to the Mary River system could also be a concern to young turtles. I've seen pictures of them from Gympie, Imbil and Kenilworth. Sooty's are native to more northern parts of Australia , they are aggressive feeders and bully a lot of other native fish species. Could young bum breathers be harassed by hordes of Sootys in the future? Who knows. They probably already are.
Cheers,
Dave.