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crop. This is much higher than simply the cost of producing the cotton in a given year because of the need to absorb ongoing costs associated with the investment into the infrastructure and machinery associated with the cotton operation. Therefore, in order to achieve profitable integration through multiple use of water storages, an aquaculture operation must not place significant demands on the farm’s water resources. Systems like the floating raceways used in this study enable the water depth in ring tanks to be lowered to a minimal depth. This is beneficial as unlike cages that require a greater functional water depth, the raceway systems can operate in less water and therefore make more water available for irrigation. The economics of farm integration are complex as many of the inputs, resources and infrastructure are shared across the farm’s operations. As part of this study an Excel based spreadsheet decision tool was developed to assist growers investigate the potential for integrating aquaculture into their farm operations. Intended as a guide only, this model indicates that the demonstration farm’s overall profitability could be improved substantially if the documented technical and operational challenges faced during this study can be overcome. Implications and Recommendations It is clear from this study that while the aquaculture potential of these regions and infrastructure is high, there are existing issues concerning the methods and timing of water harvesting, the species used, the method of farming and the associated demands on the farm operators. The level of intensity and scale of production must be well matched to the skill of the proponent and the available infrastructure. Considered placement of the aquaculture operation will determine the success of the operation and its ability to expand. In conclusion, the irrigation industry is well placed to invest in the production of additional crops from their available water resources and infrastructure, the cotton industry is particularly well placed because of its commitment to environmental management and sustainability. It is recommended that irrigators seeking to introduce aquaculture into their existing farming enterprises investigate: • The impact of retaining up to 3m of water within the aquaculture storage on the farms irrigated crops. • The risk associated with servicing a new and highly technical farming enterprise. • The cost of additional training requirements for new and existing staff. • The minimum size that the aquaculture enterprise must achieve compared to the capacity that exists within their farm infrastructure. • The species that is optimal for their proposed system (extensive, semi-intensive or intensive). • The ability of the farm to maintain water supplies indefinitely. xii
1. Introduction 1.1 General Background Large volumes of water are harvested in southern Queensland and stored for production of agricultural crops. On the Darling Downs hundreds of water storage or ‘ring tanks’ have been built by irrigators to hold many thousands of mega litres water. The major irrigated crop in this region is cotton. In Queensland 2001/2002 there were 96,700 hectares (ha) planted with cotton of which 79,800ha was irrigated production, of this the Darling Downs accounted for a total of 44,000ha of which 28,00ha was irrigated (ACG, 2006). Australia consumes approximately 22,185 GL of water annually of which about seventy percent (15,502 GL) of the total water used is consumed for agricultural production of which approximately 11.9 per cent (or 1,840 GL) is consumed by the cotton industry (Dalton, Raine, & Broadfoot, 2001). The cotton industry is second only to the horticultural industry in terms of value derived from the water resource (ABS, 2000) returning a farm gate value of approximately $613 per ML consumed (Dalton, et.al, 2001). The Australian Bureau of Statistics (ABS) reports that for 2002/2003 Australian irrigated cotton farmers used an average of 6.5 ML/ha of water (ABS, 2006). The cost of water in real terms is increasing for growers and farm diversification is becoming an increasingly important consideration for farmers seeking to obtain more value from their water allocations and infrastructure. As a consequence of the cotton industry’s access to water and associated infrastructure, opportunity exists to integrate aquaculture into established cotton farming operations. Successful integration would provide significant socio-economic benefits for cotton growers as well as a number of other rural industries and their communities. Estimates of surface water storage capacities for the Condamine River catchment (Darling Downs region) are as follows. There are approximately 2,679 ring tank type storages with a total surface area of 6,115 ha with individual storages being about 2.28 ha in size on average. Palustrine/lacustrine water bodies that have been converted, completely or mostly, to a ring tank or other controlled storage account for an additional 305 storages with a total surface area of 763 ha with individual storages being about 2.5 ha in size (EPA, 2006). Fish farming as an integrated operation with irrigated cotton production is not a new concept and has been successfully practised with furrow and drip schemes in the United States and Israel. Potential exists to incorporate the same practices on Australian farms. Existing cotton water storages or ‘ring tanks’ vary in size from 10 to 50 ha with depths ranging from 4 to 7 m. These storages are usually filled by pumping riverine and overland flows when available. In some cases, a farms groundwater supplies are also used to supplement surface water supplies. In assessing the potential of individual ring tanks for fish production not only must the location and design of the ring tank be considered but so must the availability, source and quality of the farms water supplies and its use of agricultural chemicals. The depth of water held in any ring tank varies in accordance with a farms irrigation schedule, river flows, on farm rainfall patterns, evaporation rates and seepage. The depth of most storages means that there is potential for stratification of the water body which can result in oxygen levels in the deeper portion of the storage to become depleted while the levels in surface layers remain normal. This lack of mixing has the potential to cause problems for aquaculture when seasonal climatic conditions cause the water body to ‘turn’. Such an event brings the low oxygen water to the surface and in contact with fish and can result in death of fish in severe cases. The risks posed to aquaculture in cotton ring tanks by seasonal stratification needs to be assessed and any means of mitigating its impact determined. The timing and path by which water enters a ring tank will be of critical importance in determining the quality and quantity of water available for aquaculture. Water bodies that are highly turbid (has high levels of suspended solids such as fine clays) and have low dissolved oxygen levels are usually unsuitable for fish culture. Studies on catchments with predominant agricultural developments have 1
Page 1: Integrated Agri-Aquaculture Demonst
Page 4 and 5: © 2009 Rural Industries Research a
Page 6 and 7: Acknowledgments The authors would l
Page 8 and 9: Contents Foreword .................
Page 10 and 11: Table 4.3.11 Table 4.3.12 Table 4.3
Page 12 and 13: Executive Summary What the report i
Page 16 and 17: documented such waters types as bei
Page 18 and 19: 2. Demonstration Farm 2.1 Backgroun
Page 20 and 21: Figure 2.2.3 Net cages used for sil
Page 22 and 23: 3. Water Use and Quality 3.1 Backgr
Page 24 and 25: inland Australia with high levels o
Page 26 and 27: Table 3.3.3 Average monthly afterno
Page 28 and 29: 169 165 161 157 153 149 145 141 137
Page 30 and 31: In February 2001, enough water was
Page 32 and 33: 4. Production Systems and Growth 4.
Page 34 and 35: Figure 4.2.3 The first 7m 3 floatin
Page 36 and 37: Figure 4.2.7 Uplift, baffle board a
Page 38 and 39: float to prevent drowning of air br
Page 40 and 41: Figure 4.2.13 Raceway push gate gra
Page 42 and 43: Table 4.3.1 Number and volume of ne
Page 44 and 45: Table 4.3.3 The length of culture p
Page 46 and 47: Stock retention was also high in th
Page 48 and 49: Table 4.3.10 The length of culture
Page 50 and 51: 4.3.5 Disease Detection and Treatme
Page 52 and 53: The average rate of growth for silv
Page 54 and 55: R E Figure 4.4.1 Existing (E) and r
Page 56 and 57: 5. Pesticide Monitoring and Residue
Page 58 and 59: 5.2.1.1 Pesticide Application and U
Page 60 and 61: prior to the commencement of the tr
Page 62 and 63: 5.4.2 Pesticide Bio-concentration a
Page 64 and 65:
0.4 0.35 0.3 0.25 ug/L 0.2 0.15 0.1
Page 66 and 67:
There were no detections of endosul
Page 68 and 69:
While further expansion of the inte
Page 70 and 71:
7. General Discussion The integrati
Page 72 and 73:
Appendix Floating Raceway Technolog
Page 74 and 75:
Why Raceways? McVeigh Brothers P/L
Page 76:
Alternative but Adaptable System Mc
Page 79 and 80:
Water Flow (eddy) Flow (cm/sec) 35
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End gates - changeable 67
Page 83 and 84:
35 g average fish - 3200 each 120 g
Page 85 and 86:
Paul McVeigh Mark Fantin Doug Young
Page 87 and 88:
Das, B., Sharif, Y., Khan, K., Das,
Page 89 and 90:
Müller , J.F., S Duquesne, Jack. N
Page 91:
Integrated Agri-Aquaculture Demonst
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