Most people know that fresh fish and leafy greens can contribute to a healthy diet. The combination can also have a positive impact on water quality, when you grow them together.

Researchers at West Virginia University are expanding their investigation into aquaponics – a sustainable production system that combines aquaculture (fish farming) with hydroponics (cultivating plants in water). Their work will be funded by a Conservation Innovation Grant from the U.S. Department of Agriculture’s Natural Resource Conservation Service.

Karen Buzby, a post-doctoral fellow in environmental engineering in the College of Engineering and Mineral Resources and other aquaculture investigators, have been studying the potential of aquaponics for more than five years as part of the Aquacutlure Food and Marketing Development Project. This new grant has given them the opportunity to study that potential at a production scale.

The aquaponics team is conducting its studies in flowing-water aquaculture systems at the Reymann Memorial Farm near Wardensville, W.Va., and at two commercial fish production operations in West Virginia. Flowing-water systems are preferred by trout producers as an efficient and manageable production system. They’re generally fed by groundwater flowing by gravity from springs or mines.

The facility at the Reymann Memorial Farm, overseen by program coordinator Matthew Ferrell, allows investigators to conduct experiments under conditions comparable to commercial producers growing trout for food or recreation. The Rainbow Head Farm near Clarksburg, W.Va., aims to produce fish for the recreational market and uses well water to hold and grow fish for market. Wilson Mills Farm near Lindside, W.Va., grows trout for both the recreational and food markets and draws its water supply from a natural spring.

“The three farms demonstrate a range of water usage – from about 2,500 gallons per day to an excess of 1 million gallons per day – as well as a range of production levels,” said Ken Semmens, aquaculture specialist with the WVU Extension Service and aquaculture project leader at the WVU Davis College of Agriculture, Natural Resources and Design.

In these systems, fish release nutrients into the water creating an opportunity for the production of plants. The aquaponics team has screened a variety of plants to determine which plants are suited to this kind of aquaponic production – greens like lettuce, watercress, chard, kale, kohlrabi, and even ornamentals like nasturtiums, dianthus, and calendula. Now, the task will be to translate laboratory-based research to larger production systems.

According to Buzby, the aquaponics system has shown success in removal of soluble nutrients from the water flow. These nutrients include ammonia, nitrates, nitrites, and phosphates, all of which influence water quality. As regulatory agencies have become more stringent, producers around the Potomac basin have become increasingly sensitive to the need for management of nutrients in surface waters.

In addition to reducing the environmental impact of fish-production systems, aquaponics may also offer an extra source of income for fish producers. The addition of vegetable and flower production increases the volume and diversity of goods for market. Investigators also note that lettuce production can be conducted year-round. The consistent temperature of spring water provides conditions for cold-weather crops in the dead of winter and the heat of summer, times when these crops don’t do well in exposed soil.

Plant screening of vegetable and ornamental crops will be conducted by Nicole Waterland, an assistant professor of horticulture in WVU’s Davis College. Waterland will identify crops that will grow well within each of the three diverse systems in the study.

“As each flow-through aquaponic system is unique as to water availability and water quality characteristics such as temperature, pH, and nitrate and phosphate concentrations, it’s essential that screening of potential crops be conducted,” Waterland explained.

Plant screening at the at Reymann Memorial Farm indicated that water temperature was a critical factor determining which crops would grow at the facility and identified several potential crops that either did not germinate or failed before producing a crop. Potential crops will be identified through evaluation of germination and growth preferences.

Lance Lin, an assistant professor of civil engineering and principal investigator on the project, said that the next steps for aquaponics research may be economic, exploring the large-scale financial feasibility of adding aquaponics to fish production systems.

“This project serves as a great example of how economic development and environmental protection can be achieved at the same time while we strive to cope with limited water resources,” Lin said.

“In this case, added income from vegetable and ornamental crops may be supplemented by improved water quality creating a win-win situation.” Semmens said.

-WVU-

dw/09/12/11

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