IFS News - Hatchery Reportby Sarah Graham
This Hatchery Report covers the work of the IFS hatchery staff during April. It covers the collection of brown trout ova and grading of fish to complete the stocking of remaining waters in the annual wild brown stocking program.
During mid April an early run of brown trout enabled staff to collect 160,000 ova from fish trapped in the Liawenee trap. Half of these will be left to grow as diploid fish while the other 80,000 will be developed as triploid ova. The number and quality of the brown trout was good, many of the females were still firm and the majority of the run consisted of males. The ova collected have been successfully placed into the incubators at New Norfolk and appear to be in good order. A second batch of ova was collected in early May and a third collection will take place in late May or early June. However, if the first two batches develop and hatch successfully, a third collection may not be required to be hatched and reared for stocking the recreational fishery. Last year’s ova harvest turned out to be surplus to the fishery’s requirements and the back log added pressure to the management of the hatchery. A more qualitative approach is being taken for 2011-12. Two separate orders for brown trout ova have been placed with IFS. 100,000 ova will be collected, nurtured and freighted to the South Australian Fly Fishers association and 40,000 brown ova will be freighted to the Ballarat Acclimatisation Society in Victoria. Both these independent bodies ordered and received the same quantities last year. These ova will be collected around the Liawenee Open Weekend. The ova will be carefully packed and freighted in specially designed boxes at an eyed up stage, approximately a week prior to the expected hatching date. Hatchery staff are grading as many larger fish as possible to increase stocking activity. Approximately 60,000 10g rainbow trout have been released into Great Lake for the month and another 40,000 10g plus diploid rainbow have been graded off to complete the proposed stocking of 100,000 for Great Lake. The remaining 40,000 will be stocked in at the next opportunity. The remaining browns are all close to the optimum size of 20g, ready for dispersal to those remaining waters that have Redfin perch. The fin clip brown trout were released into the BreakODay River in the first week of May. By the end of May, the majority of remaining fish in the hatchery should be stocked out. Adult transfers from Liawenee canal will commence in early May and may continue into June. Success of the adult transfers is dependent on numbers in the run. Supplementary stock may be collected from Hydro Creek at (Arthurs Lake) and Mountain Creek at (Lake Sorell) depending on the run at Great Lake.