Drawing an association between wood and fish would elude most people, but the simple fact that roughly two thirds of Alabama is covered in trees has major implications for some facets of the state’s aquaculture industry. 

In fact, one expert contends that trees could provide at least some elements of this industry with the competitive advantages sorely needed to compete with foreign-grown products.

Alabama possesses ample amounts of wood — and not just the timber commercially harvested — but also the waste products left behind when these lush green forests undergo occasional thinning.

It’s often said that one’s person trash is a another person’s treasure — a maxim that definitely applies to the state’s fledgling aquaponics industy, according to Gregory N. Whitis, an Alabama Cooperative Extension System aquaculturist, who believes Alabama’s abundance of wood offers distinct advantages to this emerging sector.

Aquaponics is a food production system in which aquatic species, such as tilapia, are grown along with plants within a controlled, mutually sustaining system.  In such a system, the nutrient-enriched water from fish culture is channeled to irrigate nearby plants, whether these happen to be vegetables or herbs.

But one of the factors that has limited growth of this sector until now is the cost of conventional heating, according to Whitis.

Deprived of key advantage

Sunny Alabama is blessed with an unusually long growing season, but fish and plants sooner or later have to be brought inside with the onslaught of cooler temperatures. This has deprived aspiring Alabama aquaponic producers with a key advantage compared with tropical countries that enjoy year-round growing conditions.

“If you plug a heater into the wall to support an aquaponics system, you’ll go broke eventually,” says Whitis. “There’s no way to justify that expense when raising a tropical species like tilapia in a temperate environment.”

But factoring in Alabama’s copious supply of wood products changes these dynamics.

“If you have 60 acres of timber with about 600 trees per acre and undertake a pre-commercial thinning that reduces these to 400 trees an acre, a lot of biomass falls to the ground,” Whitis says.

“A market for this wood would be appealing to some small timber owners.   Even though pine has a lower BTU rating compared to hardwoods, it will still heat water at a low cost.”

Other wood waste products are also comparatively cheap. For example, one Dallas County tilapia grower buys only bark slabs from a custom saw mill. The bark costs about $20 for 8,000 pounds, to heat his facility — an unusually cost-effective energy investment, Whitis says.

“About $20 worth of this forestry waste will cover four days of heating in a large scale indoor aquaculture facility, which amounts to $5 a day in heating costs,” he says. “Folks up north who have only electrical heating as a source can’t compete with that.

“And bear in mind: Clear cuts rank really high in the availability of low-cost biomass. All those hardwood tree tops are holding incredible amounts of low-cost energy.”

This point was underscored to Whitis while he operated an aquaponics project on an experimental basis, using a facility that had previously been used by the Hale County Vocational Center to teach aquascience.

But even while he perceives great potential for forestry waste as a heating source for the state’s emerging aquaponics industry, he stresses caution.

Asian producers hold two critical advantages over U.S. producers: long growing seasons and an inexpensive labor force, which provides a key competitive edge in processing, Whitis says.

“We can’t afford to grow tilapia and process them on a large scale too, at least until the American consumer is willing to pay a higher price for U.S-grown seafood.”

Currently, more than 99 percent of the tilapia products consumed in the United States — the kind bought from big seafood restaurant chains — are imported, according to Whitis.

Growing demand for American product

Even so, Whitis perceives a growing demand among U.S. consumers for American-grown fish products — and that fact affords aspiring aquaponics growers with another critical advantage.

“With aquaponics, you’re dealing with a product that is by necessity all natural,” he says. “By its nature, this production system keeps you honest because if you use pesticides on your plant crops, you’re going to harm your fish, and if your fish perish, the system collapses.”

As an effective marketing strategy, Whitis advises prospective growers to form partnerships with one or more local restaurants and to stress that the fish are raised in a pesticide-free environment.  However, since few of these restaurants are set up to dress fish, few will buy live product.

One viable alternative for producers is to complement their aquaponics operations with small processing facilities that are in compliance with local health codes.

Prospective growers also face the added challenge of attaining a scale that is commercially feasible.

Based on his own research and experience, Whitis says the minimal size of such a facility typically encompasses about 3,000 square feet and concentrates on higher-end vegetables and herbs.

“Staggered fish production is a key too,” Whitis says. “You have to time your harvests and sell fish during the year, not just one crop per year.”

Tilapia is one of several species most ideally suited to aquaponics production. 

Whitis says that tilapia grown to two pounds helps secure a sustainable aquaponics system.

 “In the course of feeding the tilapia, you’re also adding fertilizer to the water, which, in turn, is used to irrigate whatever plants you choose to grow,” he says, adding that a few compounds, such as potassium and iron, still have to be added to ensure optimal growing conditions for the plants.

Whitis says producers often opt to be highly diversified, growing as many as 20 different varieties of herbs and vegetables along with the fish. However, Whitis says experience has demonstrated that hot peppers, basil and cucumbers work exceptionally well in such a system.

 

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