Finfish production in a static, inland saline water body using a Semi-Intensive Floating Tank System (SIFTS)

Using a newly developed culture technology known as the Semi-Intensive Floating Tank System (SIFTS), rainbow trout (Oncorhynchus mykiss), mulloway (Argyrosomus japonicus) and barramundi (Lates calcarifer) were produced in a 0.13 ha static, inland saline water body over a period of 292 days, yielding the equivalent of 26 tonnes/(ha year). Rainbow trout were grown with an FCR of 0.97 from 83 to 697 g over 111 days (specific growth rate (SGR), 1.91%/day) between June and September, when average daily water temperatures ranged from 12.3 to 18.2 °C. Over the same time period, mulloway grew only from 100 to 116 g, however, once temperatures increased to approximately 21 °C in October, food intake increased and mulloway grew to an average size of 384 g over 174 days with an SGR and FCR of 0.68%/day and 1.39, respectively. Barramundi stocked in November with an average weight of 40 g increased to 435 g in 138 days (SGR 1.73%/day) with an FCR of 0.90. The SIFTS significantly reduced nutrient input into the pond by removing settleable wastes as a thick sludge with a dry matter content of 5–10%. The total quantity of dry waste removed over the culture period was 527 kg (5 tonnes/(ha year)), which was calculated to contain 15 kg of nitrogen (144 kg/(ha year)) and 16 kg of phosphorus (153 kg/(ha year)). The release of soluble nutrients into the pond resulted in blooms of macro- and micro-algae which caused large and potentially lethal diurnal fluctuations in dissolved oxygen within the pond, however, comparatively stable levels of dissolved oxygen were maintained within each SIFT1 through the use of air lift pumps.