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Wilson A. Lennard
University of South Australia, UniSA STEM, South Australia, 5000, Australia

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Withdrawal
Published: 06 February 2021 in Aquaculture and Fisheries
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Murray Cod, Maccullochella peelii peelii, and Green Oak lettuce, Lactuca sativa, were used to determine the effects of three different starting nitrate concentrations, in a research-scale aquaponic system using gravel bed hydroponic components: control (initial nitrate = 0 mg/L), medium nutrient (initial nitrate = 25 mg/L) and high nutrient (initial nitrate = 50 mg/L), where plant nutrients were supplied from fish wastes while the plants removed nutrients from the water before it was returned to the fish tanks (25.9 g of fish feed/m2 of plant growing area/day). Murray Cod had FCR's and biomass gains that were statistically identical in all systems (mean SGR = 1.16%/replicate/day; mean FCR = 0.84). Lettuce, in terms of biomass gain and yield, within both the medium and high nutrient treatments (medium yield of 4.28 kg/m2 and high yield of 4.41 kg/m2) had superior results when compared to the control (yield of 3.47 kg/m2). In terms of nitrate removal (nitrate accumulation: control = 5.60 mg/L; medium nutrient = - 0.50 mg/L; high nutrient = - 1.57 mg/L) and phosphate removal (phosphate accumulation: control = 0.92 mg/L; medium nutrient = - 5.53 mg/L; high nutrient = - 9.04 mg/L), conductivity accumulation (control = 237 μS/cm; medium nutrient = 186 μS/cm; high nutrient = 189 μS/cm), pH, buffer additions (control = 0.7 g/day; medium nutrient = 0.9 g/day; high nutrient = 0.9 g/day) and water use (control = 1.15 L/day; medium nutrient = 0.98 L/day; high nutrient = 1.04 L/day), no statistical difference was observed between any treatments. Overall, results demonstrate that starting nitrate concentrations (with nutrients derived from fish wastes) between 25 mg/L and 50 mg/L provided improvements in the research-scale aquaponic system for plant yield. This study demonstrates nutrient levels should be allowed to accumulate in coupled aquaponic systems by feeding fish for a few weeks before plants are introduced.

ACS Style

Wilson A. Lennard. WITHDRAWN: A comparison of the effect of starting nitrate concentration on fish growth, plant production and water quality within a research-scale, recirculating aquaponics system. Aquaculture and Fisheries 2021, 1 .

AMA Style

Wilson A. Lennard. WITHDRAWN: A comparison of the effect of starting nitrate concentration on fish growth, plant production and water quality within a research-scale, recirculating aquaponics system. Aquaculture and Fisheries. 2021; ():1.

Chicago/Turabian Style

Wilson A. Lennard. 2021. "WITHDRAWN: A comparison of the effect of starting nitrate concentration on fish growth, plant production and water quality within a research-scale, recirculating aquaponics system." Aquaculture and Fisheries , no. : 1.

Journal article
Published: 08 August 2020 in Aquaculture and Fisheries
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Murray Cod, Maccullochella peelii peelii, and Green Oak lettuce, Lactuca sativa, were used to test for differences between four buffering regimes in a research-scale, recirculating aquaponic system consisting of twelve, separate 140L aquaponic units. In the aquaponic system, where plant nutrients were supplied from fish wastes and plants stripped nutrients from the water before it was returned to the fish, the buffers tested were potassium bicarbonate, calcium hydroxide, mixed (an equal mixture of potassium bicarbonate and calcium hydroxide) and a control where the buffer used was sodium bicarbonate. Murray Cod had FCRs and biomass gains that were statistically identical in all treatments (SGR = 1.19%/replicate/day; FCR = 0.86). Lettuce yields were determined over a 21-day trial, with the potassium treatment (yield of 4.75 kg/m2) and mixed treatment (yield of 5.00 kg/m2) providing the highest production. Potassium and mixed treatments also had lower levels of nitrate accumulation (potassium treatment = 7.80 mg/L; mixed treatment = 8.77 mg/L) and the lowest levels of water use (potassium treatment = 1.59 L/day; mixed treatment = 1.60 L/day) compared with the other test treatment and the control. Mixed and calcium treatments yielded the lowest phosphate accumulations (mixed treatment = 2.81 mg/L; calcium treatment = 2.60 mg/L), but the calcium treatment may have been affected by calcium–phosphate complexing which may have led to false identifiable phosphate concentrations. For dissolved oxygen, pH and conductivity, no statistical differences were observed. Overall, results suggest that potassium-based buffer salts were superior to the other buffers tested in the research-scale aquaponic system tested.

ACS Style

Wilson A. Lennard. A comparison of buffering species and regimes applied within a research-scale, recirculating aquaponics system. Aquaculture and Fisheries 2020, 1 .

AMA Style

Wilson A. Lennard. A comparison of buffering species and regimes applied within a research-scale, recirculating aquaponics system. Aquaculture and Fisheries. 2020; ():1.

Chicago/Turabian Style

Wilson A. Lennard. 2020. "A comparison of buffering species and regimes applied within a research-scale, recirculating aquaponics system." Aquaculture and Fisheries , no. : 1.

Journal article
Published: 15 May 2020 in Water
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To assist waste management decision-making, there is a need to assess the economics of commercial-scale reuse of recirculating aquaculture system (RAS) effluent in horticulture. This study compared the feasibility/viability of using two representative horticulture systems, considering their distinct hydrological characteristics, in horticultural reuse schemes for RAS effluent. These representative systems included a soil-based system in field conditions (SOIL-FIELD) and a hydroponic system in greenhouse conditions (HYDRO-GH). A novel two-step hydro-economic modelling approach was used to quantify and compare the effluent storage volume, total land area, capital expenditure and crop price required for feasible/viable end-of-pipe reuse in the two systems. The modelling assessed several water management scenarios across four Australian climates. Results showed HYDRO-GH, reusing 100% of the annual effluent load and targeting an internal rate of return of 11.0%, required approximately 3 times more land, 14 times more capital expenditure and 5 times the crop price of SOIL-FIELD, targeting a 3.6% internal rate of return. As well as comparing two horticulture systems, this study presents a method to assess feasibility/viability of horticultural reuse schemes for other industrial wastewaters, using a water balance design approach.

ACS Style

Eugene Moore; James Ward; Wilson Lennard. End-of-Pipe Horticultural Reuse of Recirculating Aquaculture System Effluent: Comparing the Hydro-Economics of Two Horticulture Systems. Water 2020, 12, 1409 .

AMA Style

Eugene Moore, James Ward, Wilson Lennard. End-of-Pipe Horticultural Reuse of Recirculating Aquaculture System Effluent: Comparing the Hydro-Economics of Two Horticulture Systems. Water. 2020; 12 (5):1409.

Chicago/Turabian Style

Eugene Moore; James Ward; Wilson Lennard. 2020. "End-of-Pipe Horticultural Reuse of Recirculating Aquaculture System Effluent: Comparing the Hydro-Economics of Two Horticulture Systems." Water 12, no. 5: 1409.

Chapter
Published: 22 June 2019 in Aquaponics Food Production Systems
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Aquaponics is a technology that is part of the broader integrated agri-aquaculture systems discipline which seeks to combine animal and plant culture technologies to confer advantages and conserve nutrients and other biological and economic resources. It emerged in the USA in the early 1970s and has recently seen a resurgence, especially in Europe. Whilst aquaponics broadly combines recirculating fish culture with hydroponic plant production, the application of the term aquaponic is broad and many technologies claim use of the name. Combining fish culture with aquatic-based, terrestrial plant culture via aquaponics may be better defined via its nutrient resource sharing credentials. Aquaponics applies several principles including, but not limited to, efficient water use, efficient nutrient use, lowered or negated environmental impact and the application of biological and ecological approaches to agricultural fish and plant production. Water sources are important so that the nutrients required for fish and plant production are available and balanced, and system water chemistry is paramount to optimised fish and plant production. Systems may be configured in several ways, including those that are fully recirculating and those that are decoupled. Aquaponics importantly seeks to apply methods that provide technical, biological, chemical, environmental and economic advantages.

ACS Style

Wilson Lennard; Simon Goddek. Aquaponics: The Basics. Aquaponics Food Production Systems 2019, 113 -143.

AMA Style

Wilson Lennard, Simon Goddek. Aquaponics: The Basics. Aquaponics Food Production Systems. 2019; ():113-143.

Chicago/Turabian Style

Wilson Lennard; Simon Goddek. 2019. "Aquaponics: The Basics." Aquaponics Food Production Systems , no. : 113-143.

Journal article
Published: 09 April 2019 in Horticulturae
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A comparison of leafy green plant species’ (lettuce (Lactuca sativa L.), dill (Anethum graveolens L.), rocket (Eruca sativa), coriander (Coriandrum sativum L.), and parsley (Petroselinum crispum)) growth rates was performed between an Nutrient Film Technique (NFT)hydroponic system, using standard commercial nutrient solution, and an NFT aquaponic system, using fish waste from Grass Carp, (Ctenopharyngodon idella) which provided the majority of the nutrients required by the plants. The results demonstrated that the aquaponic method performed well, and, in many cases, the growth rates produced were similar to those of the hydroponic method. Lettuce growth was compared across three seasons (summer, winter, and spring), and, in all cases, the aquaponically-grown lettuce equalled, or bettered, the hydroponic equivalent. Herb growth was compared over a five-month period (February to June—summer/autumn), and in 17 out of 23 comparisons, the aquaponic method produced results similar to those of the hydroponic method. Thus, while the NFT method may not be the most appropriate technical approach for aquaponic integration, the results suggest that the overall aquaponic method has the potential to produce plant growth rates at least equal to those of standard hydroponics.

ACS Style

Wilson Lennard; James Ward; Ward. A Comparison of Plant Growth Rates between an NFT Hydroponic System and an NFT Aquaponic System. Horticulturae 2019, 5, 27 .

AMA Style

Wilson Lennard, James Ward, Ward. A Comparison of Plant Growth Rates between an NFT Hydroponic System and an NFT Aquaponic System. Horticulturae. 2019; 5 (2):27.

Chicago/Turabian Style

Wilson Lennard; James Ward; Ward. 2019. "A Comparison of Plant Growth Rates between an NFT Hydroponic System and an NFT Aquaponic System." Horticulturae 5, no. 2: 27.