Piloting an Integrated, de-coupled aquaponics system for sustainable feed production.

The trial will occur on and nearby Elko Evans farm in Waimanalo O’ahu. Climate is conducive to year round production of the species used in this trial: taro, sweet potato, cassava and Chinese catfish. Average rainfall is 60 in per year average daily temperature is 81 F, and the soil is a mollisol (Waialua series) with relatively high native fertility. 

We will Install and maintain fifteen 1,000 gallon tanks, each stocked with 300 Chinese catfish, with a final harvest density of 20 kg/cubic meter. The fish will be fed twice daily to satiation throughout the experiment and harvested once the reach ¾-1 lb body weight. Water quality will be monitored daily for temperature and dissolved oxygen and weekly for ammonia, nitrite, nitrate and pH. Tanks will be raised above production beds to irrigate crops with catfish effluent and no supplemental nutrients using gravity to eliminate the need for water pumps. Crops will be irrigated with 10-25% of the total volume of each fish tank daily to meet the evapotranspiration demand. 

We will plant out roughly 1 acre of a combination of sweet potato, taro and cassava, arranged in a randomized split-plot design, with 3 replications of ~14,000 ft2 each. All crop species will be planted in each replication as the main plot, 3-5 Cultivars of each crop as the sub plots to account for potential intra-specific differences in adaptation to aquaponic production. Specific cultivars are expected to include:

Taro- Moi, Lehua, Palehua. 

Sweet potato- Uala Kea, HM-26 and HM-17

Cassava- Locally adapted cultivars provided by UH cooperative extension agent Sharon Wages

Methods of data collection and data analysis will monitor the performance of the aquaponic system and the growth of the crops. TAs Fox and Radovich will supervise data collection and will be primarily responsible for statistical analysis using Statistix and other appropriate software (e.g. SigmaPlot, R). A general approach towards data collection follows:

Fish Growth and Health: Collect data on Chinese catfish growth, including measurements of length and weight, along with health parameters. This data should be collected regularly, ideally on a daily basis, to monitor the performance of the aquaponic system. This data can include metrics like feed consumption, body weight, and any signs of disease.

Water Quality Monitoring: Daily monitoring of water quality parameters, such as temperature and dissolved oxygen, is essential to ensure the well-being of the fish and the efficiency of the system. Weekly monitoring of ammonia, nitrite, nitrate, and pH levels will help assess water quality and the effectiveness of the system in maintaining a suitable environment for the fish.

Crop Growth Data: Collect data on the growth and development of sweet potato, taro, and cassava crops. This will include measurements of plant height, leaf area, and yield (harvested weight). Data should be collected at regular intervals throughout the project.

Cultivar Performance: Collect data on the performance of different cultivars of taro, sweet potato, and cassava. This data will include measurements of crop yield, quality, and resistance to any potential issues. Differences between cultivars will be assessed to determine the best-performing ones for aquaponic production.

The successful completion of the objectives will be measured and evaluated using the following methods and criteria:

1. ermine the yield of taro, sweet potato, and cassava using effluent water from adjacent fish systems as the sole fertilizer source.**

- Measurement: Crop yield, including weight and quality, will be measured at harvest.
- Evaluation: The comparison of yield between crops grown using fish effluent as the sole fertilizer and traditional methods will determine the success of this objective. Statistical analysis will reveal any significant differences in yield.

2. Compare fish growth rates in a commercial scale DAP system versus a closed-loop aquaponics system.**

- Measurement: Fish growth data, including weight, length, and health metrics, will be recorded regularly throughout the project.
- Evaluation: By comparing the growth rates and health of fish in the DAP system and the closed-loop aquaponics system, the success of this objective will be determined. Statistical analysis will reveal any significant differences in growth rates.

3. Assess costs of production in a commercial scale DAP system relative to closed-loop systems.**

- Measurement: Detailed records of expenses related to the DAP system and closed-loop aquaponics system will be maintained.
- Evaluation: A cost-benefit analysis will be conducted to compare the expenses associated with each system. The success of this objective will be measured by identifying which system is more cost-effective and economically viable.

4. Increase the awareness of 150 producers of recent innovations in aquaculture and aquaponics to improve on-farm profitability.**

- Measurement: The number of producers reached and their engagement with the information will be tracked through surveys and attendance records at educational events.
- Evaluation: The success of this objective will be measured by the extent to which 150 producers are educated about the innovations in aquaculture and aquaponics. The impact on their on-farm profitability will also be assessed through follow-up surveys and feedback.

The successful completion of these objectives will be determined through a combination of data analysis, statistical comparisons, and assessments. This will provide a comprehensive evaluation of the project's outcomes, including the impact on crop yield, fish growth, cost-effectiveness, and increased awareness among producers in the aquaculture and aquaponics community.