By Trent D'Antignana
The existing management practice for gill and skin fluke in YTK predominately relies on bathing fish in hydrogen peroxide (H2O2). However, the process of bathing fish is operationally challenging, labour intensive and at times ineffectual. Bathing with H2O2 can also result in mass mortalities to the tune of $1.0M if the amount of H2O2 added to a bathe is miscalculated or the oxygen supply during the bath is insufficient for the biomass. Considering the risks associated with bathing, the emergence of blood fluke as a potential contributor to poor fish performance and the need to develop a cohesive fluke management plan that can be implemented irrespective of weather and environmental factors there is an increasing need to assess and adopt oral medications as alternatives to bathe treatments. Of the broad spectrum anthelminthics available, orally administered Praziquantel (PZQ) has proven to be extremely effective in a variety of fish species; however, due to palatability, delivery and regulatory issues there is still no commercially applicable method of delivering PZQ effectively to YTK. This study aims to build on the work conducted in the Australian Seafood CRC project 2008/711, by optimising and improving the safe use of hydrogen peroxide, progressing the development of oral therapeutics of fluke control and identifying the trigger points for their use.
Project Objectives
- Establish a safe dose-duration-temperature curve for exposure of YTK to hydrogen peroxide.
- Establish dose-temperature relationships to effectively kill skin and gill flukes (LC99+ for effective treatment).
- Evaluate existing gill and skin fluke monitoring/assessment methods and verify that counts are representative of the cage population.
- Understand the impacts of skin and gill flukes on YTK performance and identify trigger levels for treatment.
- Progress the commercial application/use of praziquantel in YTK to treat gill and blood flukes.
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