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Scientific Journal and Magazine Articles

Here’s a small sample of the iAVs articles that were published in various journals and farmer/grower magazines.

Peer-Reviewed Publication Citations

  • McMurtry, M.R., D.C. Sanders, J. Cure, R.G. Hodson, B.C. Haning and P.C. St. Amand. 1997a. The efficiency of Water Use of an Integrated Fish/Vegetable Co-Culture System. J. World Aquaculture Society. 28 (4).

You can read/download this directly from ResearchGate.

The study was conducted to understand how well this system utilizes water compared to traditional soil-based cultivation.  The authors detail two experiments evaluating different ratios of biofilter volume to fish tank volume on the production of tilapia and tomatoes in a recirculating system where fish waste provides nutrients for the plants. The study analyzes water consumption, fish and vegetable yields, and the resulting energy and protein production, finding complex relationships influenced by the component ratios.

What they did:
• The researchers manipulated the ratio of biofilter volume (BFV) to fish rearing tank volume. They set up experimental systems with four different ratios: 0.67/1, 1.00/1, 1.50/1, and 2.25/1. This means that for every unit volume of the fish tank, they had biofilters with volumes that were 0.67 times, 1 time, 1.50 times, and 2.25 times as large. The fish tank volume was kept constant at 0.5 m³ (500 L) across all treatments, while the biofilter volume varied.
They measured the outputs of these systems in terms of:

– Efficiency of water use in protein production: How many grams of protein were produced (from both fish and tomatoes) per liter of water used.Efficiency of water use in food calorie (energy) production: How many kilocalories of food energy were produced (from both fish and tomatoes) per liter of water used.

  • Economic productivity of the system: The estimated financial returns based on the yields of tilapia and tomatoes at local market values.

Why they did it:
• The overarching goal of the study was to design and test a recirculating fish-vegetable co-culture system with high efficiency of water use for food production, along with functional and technological simplicity.

The study found that iAVs could achieve water use efficiencies ranging from 2.37 to 3.47 times greater than soil-based cultivation, depending on the system design and climatic conditions. The study suggests further research into optimizing system design, exploring different vegetable and fish species, and assessing long-term sustainability and economic impacts.

  • McMurtry, M.R., R.G. Hodson, D.C. Sanders and J. Cure. 1997b. Effects of Biofilter / Rearing Tank Volume Ratios on Productivity of a Recirculating Fish/Vegetable Co-Culture System. J. of Applied Aquaculture. 7(4): 33-51. Partial funding for this research was from the USDA Special Grant P.L. 89-106: “Agricultural Adjustment in Southeast Through Alternative Cropping Systems.”

This study focused on how the volume ratios of biofilters to culture tanks impact the overall productivity of the system. It involved different configurations of the biofilter to culture tank volume ratios, specifically 1:2, 1:1, and 2:1, using sand as the biofilter medium. Systems with higher biofilter volumes (2:1 and 3:1 ratios) showed better water quality compared to the 1:1 ratio. Fish growth was positively correlated with improved water quality. Tilapia in systems with larger biofilters (2:1 and 3:1 ratios) exhibited better growth rates compared to those in the 1:1 ratio system. Feed conversion ratios were also more favorable in systems with larger biofilters.

  • McMurtry, M.R., D.C. Sanders, P.V. Nelson and A. Nash. 1993a. Mineral nutrient concentration and uptake of tomato irrigated with recirculating aquaculture water as influenced by the quantity of fish waste products supplied. J. Plant Nutrition Vol. 16 (3), pp. 407-419.

The study investigates how varying levels of fish waste products affect the nutrient uptake and growth of tomatoes grown in sand biofilters. The research was conducted in a greenhouse using tilapia (Oreochromis mossambicus x O. niloticus) and two tomato cultivars, Laura and Kewalo, over two separate experiments in 1988 and 1989. Four different tank-to-biofilter volume ratios were tested. Nutrient concentrations in plant tissues were analyzed at various stages to determine uptake patterns. All nutrients except calcium (Ca) were assimilated at or above sufficiency levels for plant growth. Sulfur (S) was higher than needed, but no toxicity symptoms were observed. Potassium (K) became limiting when fish growth rates slowed, particularly under reduced feed conditions for mature fish. Micronutrients like iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were taken up in excess, but no toxicity symptoms were observed. The study confirmed that fish waste provided adequate nitrogen (N), phosphorus (P), and potassium (K) for tomato growth under most conditions. However, calcium deficiency was noted as a potential issue that could be addressed by modifying fish feed. A balance between fish biomass growth and plant nutrient needs is critical. When fish growth slows down or feed rates are reduced, potassium becomes limiting for plant growth.

  • McMurtry, M.R., D.C. Sanders, R.P. Patterson and A. Nash. 1993b. The yield of tomato irrigated with recirculatory aquaculture water. J. Production Agriculture., Vol.6, no. 3, pp. 331-2, 428-432.

The primary goal was to examine how the volume of biofilters (which house the plants) affects tomato yield when irrigated with water from tilapia tanks. The research focused on determining how different ratios (e.g., 1:0.67, 1:1.00, 1:1.50, 1:2.25) of fish tank to biofilter volume (BFV) influenced tomato productivity, nutrient assimilation, and water quality. The study demonstrated that increasing biofilter volume led to higher overall tomato yields per system but reduced yield per individual plant due to nutrient competition among plants. This suggests that iAVs systems can be optimized based on specific goals—either maximizing total yield or focusing on higher yields per plant. By adjusting biofilter volumes and plant densities, growers can optimize their systems for either higher total yields or better individual plant performance based on available resources and desired outcomes.

Previous integrated systems often had a lower ratio of plant/biofilter capacity to fish rearing capacity. The researchers hypothesized that increasing the biofilter volume relative to the fish tank volume would enhance nutrient recovery from fish waste by the plants, potentially leading to better water quality, reduced need for water exchange, and improved vegetable yields without supplemental fertilizers.
• By testing these four different ratios, they aimed to understand how this key design parameter influenced the system’s performance in terms of:
◦ Water use efficiency: Determining the ratio that maximizes the production of protein and food energy relative to the amount of water consumed by the system. This is particularly important in regions with limited water supply.
◦ Productivity of fish and vegetables: Seeing how the different ratios favored either fish or vegetable production. For example, a larger biofilter might provide better filtration for the fish or more growing area for the vegetables, potentially impacting their individual yields.
◦ Economic viability: Assessing which ratio could potentially offer the best financial returns based on the combined production of fish and vegetables. This allows for tailoring the system based on local market demands.
• Ultimately, the researchers wanted to identify a component ratio that could be manipulated to optimize the integrated system for specific goals, such as maximizing protein production in areas with high dietary needs or maximizing economic returns based on market trends

  • McMurtry, M.R., P.V. Nelson, D.C. Sanders and L. Hodges. 1990a. Sand culture of vegetables using recirculating aquacultural effluents. J. of Applied Agricultural Research; Vol. 5, No. 4, pp. 280-284.
  • McMurtry, M.R., D.C. Sanders, B.C. Haning, and P.C St Amand. submitted in 1990 and again in 1994: Food Value, Water Use Efficiency, and Economic Productivity of an Integrated Aquaculture-Olericulture System as Influenced by Tank to Biofilter Ratio (HortTech; submitted twice but not published).

This paper provides empirical evidence supporting the integration of aquaculture with olericulture for sustainable, efficient, and economically viable food production. By optimizing the tank-to-biofilter ratio, growers can maximize water use efficiency, improve food production, and enhance economic returns. The study’s results are significant for regions facing challenges in agriculture due to limited water resources, offering a model for sustainable farming practices

  • McMurtry, M.R., D.C Sanders, P.V Nelson and R.G Hodson., Nutrient dynamics in an integrated recirculatory aquaculture-vegetable production system: Proc XXIIIrd International Horticultural Congress Florence Italy Aug27-Sept1 (1990c).
  • McMurtry, M.R., P.V Nelson and D.C Sanders. Mineral Content and Yield of Bush Bean Cucumber Tomato [et al] Cultivated in Sand Irrigated with Recirculating Aquaculture Water North Carolina Agricultural Research Service No11019 (1987).

No scientific investigation is done in isolation, and iAVs was fortunate in that its investigative team and the advisory body consisted of people who were at the top of their professional careers.

Here is a link to learn more about the iAVs Research Group.

Dr. Mark McMurtry’s profile on ResearchGate.

A summary about iAVs written by H. Douglas Gross, Prof Emeritus NCSU Office of International Programs (1988).

A Numerical Comparison of Two Approaches to Commercial Scale Aquaponics By Bevan Suits, AquaPlanet.