Researchers Trial Aquaponics at the University of Arkansas at Pine Bluff
By Benjamin Harrison
Hobbyists, backyard gardeners, small producers and large companies are becoming increasingly interested in the advantages of aquaponics. But it’s buyer beware in the current market.
“There have been a lot of people that will go ahead and buy what people say is going to work,” says Dr. Nicholas Romano, associate professor with the Department of Aquaculture and Fisheries at the University of Arkansas at Pine Bluff. “Then they go out of business because either they don’t have the training to do it, or the system wasn’t good to begin with.”
Still, the allure is powerful. Inland growers now have the potential to produce, in a local setting, products that are generally shipped thousands of miles from distant seaside fishermen to the dinner table.
The promises from aquaponics systems manufacturers of certain revenue expectations per square unit is unrealistic, Romano says. “My advice to [buyers] is to be very cautious going into this. Do research and talk to other successful farmers to learn from their mistakes. Don’t just believe the first guy you come across.”
Romano completed his doctoral degree in 2006 while studying aquaponics systems in Australia. From there, he completed post-doctoral work in Malaysia, where he worked with some of the most advanced aquaponics systems.
“In Singapore,” Romano says, “they had whole racks that would rotate up and down to save on space because it’s an urban area. Space is at a real premium there.” For other urban aquaponics users, Romano says, “It depends on what they want to grow and what their space requirements are.”
Most recently, he inherited the aquaponics research at UAPB and was co-funded $478,000 in a collaborative capacity grant with Kentucky State University. With that funding, he has begun his research into the potential of a new waste treatment system called Biofloc.
Biofloc is gaining in popularity among aquaponics aficionados and, essentially, minimizes the need for water change and removes the need for a filtration system. It also helps prevent the introduction of diseases from water newly added to aquaponics systems.
“When you throw in food, you’re throwing in protein,” Romano says. “That protein breaks down into waste, which is toxic to the animal.”
To get rid of that waste in the water, Romano adds a carbon source, often a sugar, starch or glycerol. This transforms wastes, like ammonia, into microbial biomass, which the animals (fish, shrimp and more) can then potentially eat while also increasing the capacity for the aquaponic system to self-regulate. Potentially, Biofloc will be used as a protein substitute in place of soy meal and fish meal, which can further reduce operating costs.
Along with this new technology, Romano is conducting a number of experiments. “We take the extra Biofloc and feed it Black Soldier Fly larvae,” he says, “to see if that enhances the nutritional value of the fly larvae.” If all goes well, these larvae are then used to feed the fish, which could turn into another potential cost-saving advantage of this technology.
Romano and his team are also experimenting to see how their animals grow and behave in these systems based on the presence of plants. “We want to see what the biggest limiting factor for the growth of the plants is,” Romano says, “which plants take out which micronutrient the fastest.”
The preferred aquaponics system design chosen by Romano and his team is a rack system. In this system, plants float on a Styrofoam container at the water’s surface, and Romano believes it has advantages over a variety of other aquaponics systems now available on the market.
Another design option is the gutter system, in which plants do not float but rather sit on top of the water, with the base of the plant closer to the water’s surface. But the problem, Romano says, is the roots grow too quickly and require frequent trimming. In his chosen system, the racks have greater depth, which means the roots require less frequent trimming, another consideration in labor costs.
During his school days in Australia, Romano grew lettuce, coriander, tomatoes, chilis and more in aquaponic systems. “But I think,” he says, “the future of aquaponics is we have to get away from all the lettuce. People are not going to be rabbits. We have to use different plant species.”
The ultimate goal for his research project is to work with other farmers in the region to understand their problems and gain insight from them, and he is seeking growers to collaborate with.
This method of agriculture’s impact on the environment is substantial, and Romano hopes to impact the sustainability of such endeavors. In the end, he looks to publish his research in scientific journals and trade magazines, to spread awareness of his learnings and to increase the ability for more growers to find low-cost methods of entering the aquaponics arena.