Substantial amounts of groundwater with a salinity >1,000 ms/cm (brackish), and upwards of 35,000 ms/cm, is extracted especially in the north west of the state where salinities are highest. Environmental water management plans that incorporate management of salinity impacts are active in all Victorian CMAs and in some areas salt interception schemes are extracting saline groundwater to mitigate the effect of rising water tables and associated increasing salinity levels.
Previous research on inland saline aquaculture in Victoria, which occurred during the 1990s and early 2000s, focused on integration of aquaculture with existing agriculture and agroforestry industries that extracted saline groundwater and saline groundwater management projects.
As part of a Serial Biological Concentration System (SBCS) for the cost-effective management and utilisation of saline groundwaters, 12 marine, brackish and freshwater species (8 fish, 2 prawn and 2 bivalve species) were cultured in two evaporation basins with different salinities (low salinity 9-16ppt, high salinity 10-25 ppt). Species selection relied heavily on availability of seedstock at the time. Mixed results were obtained. Atlantic salmon, Australian bass and black bream survived and grew in both basins. Freshwater silver perch grew exceptionally well in the lower salinity basin but died in the higher salinity basin. Survival of oysters and prawns was low, although some Pacific oysters surveyed for over nine months.
Trials conducted in saline wastewaters from the dairy industry to reduce algal standing crop showed that brine shrimp grew well and reached sexual maturity. Commercial qualities of brine shrimp (frozen blocks and live adults for the aquarium trade) were produced in saline groundwater at a salt production facility. Yield averaged 2.5 kg/M3.
Agricultural water has become a valuable and limited resource. In the face of an increasingly variable climate, the long-term resilience of farming communities will be dependent in part on the need for more diversified and complementary production strategies, which may include aquaculture. The proof-of-concept projects conducted earlier in Victoria demonstrated this opportunity. Further R&D may focus on, for example, seasonal farming of salmonids in winter and warmwater species in summer, micro-algae and macro-algae production, as well as evaluating new and emerging euryhaline aquaculture species.