Investigating waste streams in recirculating aquaculture systems and potential utilisation of waste

Supervisory Team:

Primary supervisor: Prof Chis Carter

Co-supervisor: Dr Pollyanna Hilder (CSIRO)

Additional supervisors: TBA

Brief project description:

With the expected increase in aquaculture production to meet the growing global demand for high quality protein, there will also be an increased production of aquaculture waste requiring appropriate management. In contrast to open-water fish farms, land-based recirculation aquaculture systems (RAS) can capture all of the produced waste. Historically, the disposal of waste from RAS has been both expensive and time consuming, and with the rapidly increasing number and production tonnages of land-based RAS farms around the world, the utilisation of waste as a resource is becoming increasingly important.

This project will examine the waste stream flow in the recirculating systems of the Experimental Aquaculture Facility (EAF) at IMAS Taroona. The EAF is a partnership between IMAS and the industry companies Huon Aquaculture and Skretting, and it provides specialist research facilities to support the growth and sustainability of the salmonid industry. The saltwater recirculation systems at the EAF includes 12x 7,000 L outdoor tanks, 12x 2,500 L indoor tanks and 2x 13,000 L stock tanks. Find out more information about the EAF.

The project will identify the timing, quantity and quality of waste released into the recirculating systems by collecting and analysing water samples from different water treatment components at different times. The results can then be statistically analysed and compared between the different treatments of the core experiment at the EAF.

This project will also investigate methods of sludge reduction through experimentation with anaerobic digestion and aerobic mineralisation and evaluate potential uses for the end products of these processes. Both treatments utilise biological process to degrade organic matter with microbes converting organic rich sludge into mineralised nutrient rich fertiliser, however their mode of action differs. Aerobic mineralisation utilises an oxygen rich environment and is very effective in the reduction of solids and is faster that anaerobic digestion, however, it is also a more expensive method. Anaerobic digestion, utilising an oxygen poor environment, has the benefit of biogas production and removal of harmful pathogens. Both methods will be examined to determine the suitability of application in freshwater and saltwater salmonid RAS facilities for organic sludge reduction and utilisation.

Skills students will develop during this research project:

  • RAS management
  • Laboratory techniques
  • Statistical skills
  • Written skills
Authorised by the Executive Director, Institute for Marine and Antarctic Studies
February 25, 2021