Whilst most of Queensland’s barra stocking has been in impoundments the Fitzroy River Fish Stocking Association (FRFSA), first formed back in the late 1980s, has been busy putting barra into the Fitzroy River system.
The Fitzroy River in central Queensland was one of the nation's most productive barramundi fisheries until the Rockhampton barrage was constructed in the late 1960s. This structure prevented juvenile barra from accessing the freshwater habitat that had always been so critical to maintaining the saltwater population in the system.
Luckily the system is so large that some freshwater nursery habitat still exists below the Rockhampton barrage, but these few remaining areas struggled to maintain the wild population under increasing pressure from fishing, habitat destruction and climate change.
Many of the previously viable upstream freshwater nursery areas still exist, but they no longer have juvenile barra entering them during flood events. Restocking in these areas is an artificial solution.
During the 1990s, the FRFSA regularly released barra fingerlings into various upstream creeks and lagoons. The fingerlings were 40-50mm and there was a lot of debate about stocking fish of this small size. Would forktail catfish and birds eat them before they had a chance to grow and compete?
There also wasn’t any way of knowing if any had survived to join the wild population and enthusiasm for the cause began to waver towards the late 1990s. Soon after reports of barra being caught by recreational fishers in some of the stocked locations began to appear. This was the news everyone needed – it proved at least some of the stocked barra had survived in the nursery areas.
Captag club members, the local tagging group, began catching and tagging barra in a couple of the stocked locations. During 2000, a few hundred barra, mostly 400-500mm were caught, tagged and released in the freshwater creeks and lagoons where they'd been originally stocked.
Then in February 2003, Central Queensland received enough rain to trigger a small flood that saw the stocked waterways overflow, allowing the barra to make their way downstream towards the lower Fitzroy estuary.
Unfortunately this minor flood coincided with the opening of the barra season and commercial barra netters thought all their birthdays had come at once. The lower reaches of the river were strangled by kilometres of nets and it wasn't long before reports of huge catches filtered out. Most of the fish being netted were between 600-700mm and were quite dark in colour.
A quick calculation of typical growth rates suggested the fish were the result of the stocking group's efforts in previous years. There was a total glut of barra on the market and trailer loads of barra were being driven around town in search of buyers.
A number of local commercial net fishers decided to support the tagging program and by association, the stocking program, by keeping details of tagged fish they catch. This reporting of tagged fish has confirmed that barra tagged by Captag members in various freshwater locations above the Rockhampton barrage, have travelled all the way downstream and into the saltwater section of the river.
The recovery of this information has validated the stocking association actions. There is no doubt that upstream stocking is positively enhancing the wild barra population in the Fitzroy system – just to what degree the stocking is contributing is unclear though.
FRFSA recently changed its stocking approach and now releases fewer, but much larger fish. The association now sources juvenile (200mm) barra from the Gladstone Fish Hatchery. Fish this size are more likely to survive predation from catfish and birds and will rapidly grow and establish themselves in the system.
Fish this size are also large enough to be tagged, and this is where the local ANSA (Australian National Sportfishing Association) clubs come into the picture again. All the juvenile barra stocked in the past two seasons have been tagged prior to release.
In February, 3,300 extremely healthy little barra were released into the Fitzroy River about 10-15km above the barrage at Rockhampton. The massive logistical exercise required a lot of helpers and members of the stocking group, Captag, the Keppel Bay Sportfishing Club, Gladstone Sportfishing Club and a local Rotary Club from Rockhampton all turned out to help.
During the day long event, 70 willing volunteers assisted with the daunting task of tagging over 3,000 little barra achievable. A ‘tagging production line’ was set up and half a dozen small boats were on hand to ferry eskies full of little barra up and down the river to points suitable for their release.
By about 4:00pm in the afternoon, the Fitzroy system had 3,300 more barramundi in it, each sporting a brand new yellow tag. It will be a couple of years before these little blokes reach legal size and start showing up in catches, but when they do, the information retrieved from the tags will be invaluable. Hopefully the commercial fishing industry will continue to support this important work, even if only through the return of information about tagged fish in their catch, because they probably stand to gain the most from this stocking of any single group.
Funding for three local councils on an annual basis currently provide barra stocking, plus proceeds from the Rocky Barra Bounty tag and release event ($5000 this year). The Rotary club who helped out was very impressed by the entire exercise and has pledged to donate $1000 to the cause as well.
Thanks to everyone associated with the stocking and we’re all eager to see the results in a couple of years time.Reads: 2118