The main reason for conducting this research was to investigate the possibility of producing feed for aquaculture enterprises in remote areas using locally available raw materials. In this case the major potential raw material was the waste from a local catfish wild capture fishery on Lake Argyle in the North East of Western Australia. This waste consists of the heads and frames of catfish after filleting. To make it a suitable ingredient for incorporation into fish feed pellets this by-product needs to be dried and ground.

This first stage of this project consisted of the development of a solar dryer, capable of being made on site, which would dry sufficient by-product for the project. This was intentionally a low technology approach to the problem and whilst a successful design was developed, the use of a self-contained, solar powered, extraction fan in the system increased the drying efficiency.

The dried by-product was chemically analysed and the results suggested that it could be a suitable aquaculture feed ingredient. Diets were formulated using this and other available ingredients and a 'per Tonne' cost comparison with available commercial feeds was made. This showed a large potential cost saving as long as the 'local' pellet performed satisfactorily in feeding trials.

It was also established that the formulations using the dried by-product could be pelletised using conventional methods. In this case a Lister Junior pellet press without steam conditioning. This machine is designed for on-farm use.

This concluded the first year of the investigation and it was considered that the objective to this time had been achieved. Also the method of feed production developed could be adapted to many remote sites in Australia and overseas where there is a potential for small to medium sized aquaculture operations and locally available by-products/waste products.

After a delay of 2 years for reasons given in the main report, 90-day feeding trials were conducted to compare the local pellet with a commercial product. Unfortunately these trials had to use very small barramundi fingerling (1.25 grams) and the results were disappointing. They did establish that it was feasible to use rear barramundi fingerlings on the local pellets but due, at least in part, to the lack of a facility to produce the feed in crumble form, these were not cost effective.

It was concluded that the approach taken in this project could prove to be of great benefit in remote areas but further work is required particularly with regard to producing feed of a size more suitable to the size of fish being reared. In this respect it is probable that the local pellets would prove to be of greater economic benefit when fed to larger fish.

Keywords: Barramundi, aquaculture, fishery by-product, feed production, solar drying.