With over 2.5 million hectares of salt affected land in Australia, there has been considerable interest in using salinised land and water resources to cultivate marine and estuarine finfish.
The WA Maritime Training Centre in Fremantle has been investigating the viability of such an industry, with its Aquaculture Development Unit (ADU) looking at:
A lot of useful data has been accumulated, for example, it is now known that all the saline groundwater resources in WA are deficient in potassium, relative to seawater, and for some species this deficiency must be rectified through supplementation in order to achieve good growth and survival.
The biological feasibility of growing a range of different species in inland saline water has now been proven, including:
The ADU, in conjunction with McRobert Aquaculture Systems (MAS), has patented an innovative, commercially viable culture system, known as the Semi Intensive Floating Tank System (SIFTS).
The ADU, in collaboration with CY O’Connor TAFE, and with state government funding from the Science and Technology Innovation Fund has proved the SIFTS concept on a semi-commercial scale. This research project, recently finished, has obtained excellent results. A yield of over 25 tonnes/ha/year was achieved (combination of barramundi, mulloway and trout), which compares with standard semi-intensive pond yields of approximately 2-5 tonnes/ha/yr.
Saline water pumped by the Wakool Tullakool Sub-Surface Drainage Scheme – established to drain highly saline groundwater into evaporation basins – has already produced two harvests of rainbow trout and one of mulloway, which were readily sold.
Silver perch, tiger prawns and snapper have also been trialled, but some species were found intolerant of the water’s saline content and temperature. There are also issues with marine species and the low potassium content of the water, which must be boosted with potassium to support the creatures.
Currently, there are 700 rainbow trout and 1500 mulloway being grown out. They were supplied by Port Stephens Department of Primary Industries (DPI) as 3 gm fingerlings. The work is designed to investigate inland saline aquaculture as a way to offset the high cost of salt disposal schemes. It’s also a good way of providing fresh fish supplies inland. The project is supported by the NSW DPI and Murray Irrigation Limited. Source: Penny Watts in Stock & Land (23/8/2007).
Fascinating stuff, the whole field of aquaculture – are you involved, or tempted? We’d love to hear…