The future of Glenbawn Dam as a fishery came under discussion at a forum held at the lake in October by NSW Fisheries with the assistance of the Scone Amateur fishing Club.
Around 40 anglers, fishing club members and representatives of local and State authorities, fisheries managers and scientists, attended the forum.
Cameron Westaway and Craig Watson, both managers of Fisheries stocking programs, chaired the meeting.
The chief item of discussion was that some very important decisions had to be made on the mix of fish in the impoundment, especially the ratio of bass to golden perch.
Cameron Westaway pointed out that only a special dispensation allowed golden perch to be stocked in Glenbawn and Lake St Clair in the past, as these dams are on eastern-flowing river systems.
The questions were whether it was preferable to catch a lot of relatively small bass or fewer but larger fish, and whether these dams would be stand-alone bass impoundment or provide a mix of goldens and bass.
Five scientist/managers put their opinions and theories to the forum.
Danielle Ghosn explained the summary of catch and effort data from competitions based at Glenbawn.
Data came from the past decade, from the longest-running event, the Glenbawn Classic, the ANSA convention and the Freshwater Fishing Masters. All three events are held in early Spring. Figures supported a decline in bass sizes along with a very large fall in golden perch numbers.
James Smith from the University of NSW outlined optimal stocking densities of bass, the bass’s diet and feeding habits. He also explained the effects of overstocking on fish populations.
He had very interesting information on the time bass feed, how far they can travel to feed and where these fish spend their time in the water column in relation to the thermocline. The data was gained through tracking bass fitted with transmitters.
Leo Cameron, of Southern Cross University, Lismore, explained how with electrofishing, netting and traps in five different areas of the dam researchers had caught about 800 fish, 97% of which were bass and only around 2% golden perch.
This data supported a lot of the other results pointing towards a definite decline in the numbers of golden perch, a point members at the meeting agreed with.
Karina Hall from I&I Fisheries then outlined the post-release survival of angler-caught fish and what steps were necessary for the released fish to have the greatest opportunity of survival with minimal damage.
She said there was still some work to be done in this area, especially with angler understanding and education.
The final report came from Ben Doolan, a scientist from the Port Stephens Fisheries Hatchery, who explained the problems in recent years with the bass stocking program and the steps now in place to overcome them.
After hearing all the relevant information, those attending were asked what type of fishery Glenbawn should be in future years.
The majority wanted a mixed fishery with bass and goldens, so all future stocking numbers will be based on this assumption.
This means that Glenbawn, which has already been stocked with 70,00 bass fingerlings recently, will now have the same number of goldens, instead of the proposed 20,000 outlined in the draft report.
A scientist at the meeting told me it takes a golden perch around six years to grow to 30cm, while a bass can take 10 years to grow to a similar size.
A bass of around 50cm can be 20 to 22 years old and both bass and goldens in the dam share the same diet.
I think that the correct result has been achieved by this meeting but only time will tell.Reads: 4032