Danielle Stewart
Name: Danielle Stewart
Position: Fisheries Technician, Freshwater Fisheries Research - Southern Fisheries Centre, Department of Primary Industries and Fisheries Queensland.
Education: Bachelor of Science, 2001
Experience: Senior Aquarist - Sea World and Reef HQ, GBRMPA.
Senior Aquaculture Technician and Farm Manager - Cumminscorp Limited.
Fisheries Technician - DPI&F
Aquaculture Technician - CSIRO.
Danielle is a fisheries technician for the Department of Primary Industries and Fisheries and in the past has been involved in a diverse range of areas including public aquariums and commercial aquaculture farms. After completing a Bachelor of Science in Marine Biology and Botany from the University of Queensland she was the senior aquarist for Sea World on the Gold Coast and was heavily involved in the stocking and management of Shark Bay. Danielle furthered her aquarist experience whilst working for Reef HQ within the Great Barrier Reef Marine Park Authority in Townsville.
After gaining extensive fish husbandry and management experience from public aquariums Danielle moved into the aquaculture industry where she held the position of Senior Aquaculture Technician and Acting Farm Manager at Cumminscorp Limited and later moved into the public sector with CSIRO in the area of aquaculture nutrition.
Using her background in both aquariums and aquaculture, Danielle now holds a Fisheries Technician position with DPI&F Freshwater Fisheries Research team. Although her work now is more fisheries based, working on such projects as carp control in Queensland and freshwater fish population dynamics, Danielle frequently works alongside aquaculturalist’s across the country for restocking projects and the development of new breeding programs for threatened fish populations.
TAGGING FINGERLINGS PRIOR TO STOCKING
THE PRESENTATION
Danielle is involved two projects
Improving survival of stocked hatchery reared threatened species
Murray cod, eel-tailed catfish and silver perch populations have declined dramatically in the Murray-Darling Basin and are now declared threatened or vulnerable within the Basin. The Murray Darling Basin Commission in partnership with state government agencies and regional catchment groups are helping to address this problem through its native fish strategy. The strategy includes many fisheries and environmental management projects, however where declines of some fish species have been so dramatic restocking is needed to help restore threatened fish populations.
Hatchery reared fish (fingerlings) are predominately used for restocking programs. Research has shown that hatchery reared fish have a much poorer survival than fish of wild origin of the same size. The loss of stocked hatchery reared fish can be up to 95% due to cormorant predation, and up to 99% of stocked fingerlings can be lost to fish predators within the first day after restocking. Fish that survive the first day generally have a much better chance of surviving to adulthood. Therefore if fish can be trained to recognise and avoid predators before release then their chance of survival can be greatly increased.
To date preliminary tank-based trails have been conducted where fish were trained to avoid predators for 24, 48 and 72 hours. Information collected from the tank-based experiments will be used to verify optimum predator training times for each species for field validation experiments to be conducted later in the year.
Population restoration of jungle perch (Kuhlia rupestris) in South-East and Central Queensland
The jungle perch Kuhlia rupestris is a popular recreational sportfish which takes small lures, can reach a maximum weight of 5kg. The distribution in Australia ranges from Cape York to Maroochy River. However, individuals have been captured much further south and freshwater anglers have argued that jungle perch numbers have declined in the southern part of its range.
The decline of the species has been attributed to their life history pattern. Jungle perch have a catadromous life history pattern, living in freshwater but requiring saltwater to spawn. Dams and weirs therefore affect this species, preventing migration of both juveniles and adults upstream into freshwater habitats. In order to restore populations that have experienced declines a captive breeding program must be developed as little is known about the life history and spawning requirements of jungle perch.
Preliminary work has been completed, with animals being collected from various locations around Queensland as future brood stock as well as genetic samples to determine whether there are variations within the northern, central and southern Queensland populations.
ELECTRO FISHING STOCKED FISH
A GREAT RESULT FROM STOCKING