IFS Hatchery and Stocking Report, May 2010

As the weather cools and water temperatures begin to drop, the activities of Inland Fisheries hatchery staff are hotting up! Hatchery work of fish feeding and grading has increased over recent weeks, along with fish transfers to allocated waters, and the job of harvesting eggs from spawning wild brown trout in the Central Plateau, has come earlier than in recent years.

As the weather cools and water temperatures begin to drop, the activities of Inland Fisheries hatchery staff are hotting up! Hatchery work of fish feeding and grading has increased over recent weeks, along with fish transfers to allocated waters, and the job of harvesting eggs from spawning wild brown trout in the Central Plateau, has come earlier than in recent years.  

A first batch of approximately 720,000 wild brown trout ova was collected from Liawenee Canal, Great Lake in April. About 560,000 of these eggs are now being incubated at the New Norfolk hatchery while a smaller number of 160,000 are being incubated at the Salmon Ponds as added security against loss at the main hatchery.

Adult transfers of wild brown trout have also commenced in association with ova collection from fish captured in the Liawenee trap. Approximately 2,100 of these wild brown trout spawners were transferred from Great Lake into Bradys Lake in late April.

In the hatchery tanks, about 15,000 yearling brown trout, each weighing less than 50 g on average, still remain from last year’s spawning. These young fish continue to grow well in the tanks but are more than ready for transfer. Ten thousand have been fin clipped ready for release into the Break O’Day River in early May while the remaining 5000 will be released later in the month, most likely into Craigbourne Dam.

A total population of approximately 272,300 diploid rainbow trout fry and fingerling are taking up the remainder of the tanks in the hatchery at the moment. These young fish, now weighing between 3.5 and 9 g, have been growing steadily since last year’s spawning harvest. They have adapted to life in the tanks and are feeding well, with mortality rates continuing to decline as the fish mature. In April, a proportion of this fingerling population that had matured more quickly, were released to allow more room in the hatchery with approximately 50,000 young rainbow trout going into Great Lake and 5,000 into the River Leven.