Despite the large number of impoundments currently stocked in Queensland for recreational fishing, and the economic benefits resulting from this activity, almost no research has been conducted on developing strategies to maximise survival of stocked fry. Post-stocking surveys and creel surveys have given an indication of whether a given fishery is successful or not, but these surveys have not been designed to test any hypotheses on effective release strategies. To achieve maximum productivity at minimum cost freshwater fish stocking groups require reliable information that will assist them improve stocking procedures. This information will help stocking groups to be more cost effective in their operations by increasing the chances of stocked fish reaching a catchable size. To date impoundment stocking groups have been releasing fry without knowledge of whether different size classes of fry have different probabilities of survival. Similarly it is not known if point of release of stocked fry has any influence on survival rates. Properly conducted experiments which examine the relative survival of different size classes of fry and the influence of different release strategies on survival would be of immense benefit to recreational fishing groups in Queensland and other states. If for example small fry of one species (eg barramundi) were found to survive equally well as larger size classes, then it would make sense for the stocking groups to stock the cheaper smaller size classes. If larger size classes survive well, but smaller size classes have poor survival, then fish stocking groups will have better returns by stocking the more expensive larger size classes of fry. Similarly knowledge of whether point of release has any influence on survival for different stocked species will assist stocking groups to use their time and money efficiently.
It is clear from post-stocking and creel surveys that fry survive and grow better in some impoundments than others. A number of new dams are planned in various parts of Queensland. Knowledge of the environmental characteristics which influence the productivity and carrying capacity of impoundments will also benefit stocking groups by directing their efforts to productive locations or providing advice on actions which may enhance productivity or carrying capacity of impoundments. The current proposed project is a necessary first step to develop efficient stocking protocols and will lead to a follow up experiment/project examining in greater detail the success of stocked fisheries in a up to twenty impoundments. The subsequent project is expected to lead to predictions of the suitability of new impoundments for stocked fisheries and to strategies to improve the fisheries value of impoundments.
Manual
Fish stocking is a valuable and widely used fisheries management tool. If managed well, a fish stocking program can improve the status of declining or threatened fish stocks, restore species diversity to a degraded waterway, and even create a fishery where there was none before. The positive image of thousands of small fish being released into a waterway ensures that fish stocking is equally popular among politicians, fisheries managers and the general community.
This manual provides guidelines to help plan and carry out fish stocking programs in northern and eastern Australian impoundments. It presents an introduction to the main biological and ecological concepts that determine the outcome of stocking programs, and provides community fish stocking groups with a protocol to help ensure the success of their stocking activities.
