Last Updated: Jan 8th, 2015 - 07:42:25

Future of fish farms?
By Blake Belden, Staff Writer
Jul 17, 2013, 14:22

CHESTERFIELD — Virginia State University is providing a big push for small-scale fish production.

As part of the Virginia Cooperative Extension, VSU hosted its annual Fish School event last week, giving small farmers a free tutorial on how to use fish farming as a part of their business model or a personal form of sustainability.

Dr. Brian Nerrie, a VSU assistant professor in aquaculture, said that the event is designed to give people a chance to learn about aquaculture, the farming of aquatic organisms, in a way that isn’t commonly offered.

“The whole objective here is to give individuals who are interested in aquaculture, to not only just hear about what aquaculture is, but to experience it.  So we try to get them out to handle fish, to do water quality, to do different activities,” Nerrie said.

Over the course of three days, participants gathered at VSU’s Randolph Farm research facility where they learned how to sustainably produce freshwater fish and shrimp in a small-farm setting.  Demonstrations also ranged from how to test water quality to proper farm pond management to greenhouse production and limited scale recirculation.

The Randolph Farm, located on River Road, spans 416 acres, much of which is used for research in areas of new and niche crops, alternative growing and animal production
methods and aquaculture.

Among the farm’s amenities are 130 acres of irrigated cropland, 18,500 square feet of greenhouses and high tunnels, 57 research ponds stocked with multiple species of fish, an on-site fish hatchery and an automated fish processing facility.

On Friday, the third day of Fish School, Chris Mullins, agriculture and natural resources specialist at Virginia State University, led attendees through one of the greenhouses for a demonstration on aquaponics.

Aquaponics combines the ideas of recirculated aquaculture and hydroponic plant production. It uses a symbiotic relationship where the plants and fish help sustain each other.  Many plants grow efficiently from nitrogenous wastes that are excreted by fish, while the plants help remove toxic byproducts from the water before it is recycled back into the fish tanks.

There were two different models of an aquaponic system in the greenhouse, a nutrient film technique (NFT) system  and a floating bed system.  Mullins and Nerrie walked through, in detail, the steps required of each system.

In the NFT system, nutrient rich water is channeled from tanks full of greenhouse grown tilapia (the most commonly used fish species in aquaponics) down through an elevated row of gutters in which plants can absorb the thin film of water into their roots.  The water is then recirculated back into the fish tanks using a filtration method.  NFT systems are only effective for certain leafy vegetables like lettuce, and require cleaner water and a higher filtration system.

In the floating bed aquaponic system, the fish are also grown in the same tanks used in the NFT system,  however the water is pumped into multiple channels along the ground on top of which sit floating rafts filled with plants.  The plants can extract the nutrients from the water before it is filtrated and recycled back into the fish tanks.

Because VSU is a state school,  Mullins said that much of the research done through the university is a direct reflection of specific taxpayer interest.

“People are very interested in aquaponics.  We get calls, several a month, [from] citizens of the commonwealth, our clientele, that are saying ‘I want to do aquaponics.  I want to do it.  Tell me more about it.  What can I do? What works?’” Mullins said.

Mullins said that their research often serves as a trial and error study for new agricultural methods that help minimize future complications for farmers. 

“We’ve tried various things already in the past year with [aquaponics] and we’re just trying to tweak it, and trying to make it better.  Trying to make those mistakes so that other people don’t have to. We want to be able to come to the growers with a clip book and say ‘If you do this and this and this, your  product is going to be this,’” Mullins said.

Mullins estimated that VSU has been doing aquaponic research, on and off, for about 10 years, and that it still remains to be determined the large scale economic viability of aquaponics because it is still such a new and developing concept.

Nerrie was pleased with the Fish School turnout, which included people from Goochland, Campbell County, Chesapeake and even Florida.

Jason Cowlan, from Ashland, who expressed interest in urban farming, said the fish school was very helpful.

“The whole idea is to prove to the customers, which [are] the farmers, that this can be done,” he said.

Cowlan added that VSU’s experimentation with small farming and aquaculture is entirely beneficial for prospective fish farmers.

“They do things, so if it fails to them it’s not a big deal.  They get to try it without you spending your money,” Cowlan said.

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