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Rand News

Aquaponics in frames

Aquatic tank with fish. Filtered water flowing towards the aquatic animals. The photo was taken from Bangladesh Agricultural University in Mymensingh on 31 May by Nusrat Nowrin


Aquaponics is a combination of aquaculture, raising aquatic animals, and hydroponics, soil-free method of farming. Plants and fish are raised in a symbiotic environment in aquaponics where the excretion of the aquatic bodies is fed to the plants and the plants naturally filter the waste water for the aquatic animals.

Aquaponics requires about only one-tenth water of that used in traditional soil-based agriculture. It is organic agriculture. Plants and fish could be raised on rooftop, veranda or spare places in the city and the rainwater can be used.Tomatoes are seen in an aquaponics plant. With the ripe ones being harvested, new stems will sprouted. The photo was taken from Bangladesh Agricultural University in Mymensingh on 31 May by Nusrat Nowrin

For the plant all you need is a plastic tank, brick chips or gravel, electricity, a pump and the aquatic animal's tank. Used plastic bottles can be used again for plants. An electric pump is used for siphoning. Another water pipe releases the filtered water from the plant bed into the fish tank.

Tomato, lettuce, strawberry, mint, okra, different types of spinach, papaya, eggplants, gourd, 'potol', cucumber, broccoli, pumpkin, spinach, beans and many more could be farmed in this method.

Among the fish, tilapia, catfish, koi, pangas and other local varieties can be bred. But tilapia is less stressed by environment, and can grow at the normal pace, making it a favourite with farmers.Potols are hard to grow generally. But these green potols look quite successful to meet the challenge in an aquaponics farm. Photo: Nusrat Nowrin

The main difference between soil-based and the soil-less farming is the environment-friendly recycling options.

In an aquaponics farm the harvest of plants and vegetables is continuous. Once the tomato or okra yield fruit, new stems would sprout and later provide more.”

As the farming is carried out in an organic method without pesticides, it is organic and healthy. You can plant decorative plants too.

Rock Creek Aquaculture


Nebraska is corn and beef country, and soybeans and hogs and wheat.  Not shrimp. But a shrimp farm is thriving in southeast Nebraska.  Rock Creek Aquaculture, in Diller, Neb., sixty miles southwest of Lincoln, has been raising shrimp for the past year.  Scott and Holli Pretzer and their children, son Reid, a freshman at the University of Nebraska-Lincoln and daughter Skylar, a high school freshman, started their shrimp business in March of 2017, in the old hog gestation barn that was on the farm where they grow corn and soybeans.  

After visiting a shrimp farm in Indiana, the Pretzers realized raising shrimp was a good fit for three reasons: they had a building ready to use, it was a good product, and the shrimp are raised responsibly. It also diversifies the farm operation.  The shrimp are raised in fourteen-foot vinyl swimming pools. They are born at a hatchery in Florida and flown in to Lincoln, where the Pretzers pick them up the day after they leave Florida. They are brought in in batches of 33,000 babies at a time, each as big as an eyelash. Instead of counting them, which would be impossible, they are weighed. A PVC pipe framework is put over each tank, creating a form for the plastic tarp that keeps the shrimp from jumping out. 


The shrimp are fed three times a day with a specialized shrimp feed that comes from Pennsylvania and has been well-researched. It is antibiotic-free and includes fish meal and soybean plant proteins, which appeals to Pretzer, as a soybean farmer.  The feed is broadcast into the tanks; they don’t use automatic feeders due to the high humidity in the barn, which causes problems with electric motors. The feed is in pellet form and as the shrimp grow, a larger pellet size is given them, to fit the size of their mouths. Each tank holds about 3,500 shrimp.  In about four and a half months after they arrive at Rock Creek Aquaculture, they're as big as a person's hand and ready for harvest. They are harvested by the pound; between 20 and 22 shrimp weigh a pound, "and that's a pretty good sized shrimp," Pretzer said.  

The water the shrimp live in is crucial to their well-being. The Pretzers started with well water and added 400 lbs. of salt to each tank. The water also must have the right amount and type of microbes and bacteria in it, to control nitrogen levels. The microbes and bacteria are naturally occurring, but also were added from another shrimp farm, and the Pretzers had to give them time to grow and multiply. They were able to monitor the right amount by the nitrogen content in the water. In the first batch, "we'd see spikes of ammonia and nitrite" levels, Scott said, meaning there were not enough microbes to neutralize the nitrogen. Increasing the number of microbes in the water cannot be hurried, Pretzer said. "There's no way to rush it. It has to happen over time."  

The shrimp spend their days swimming, looking for food, and eating, Pretzer said. They are very fast growers and feed efficient, and the Pretzers' job is to "reduce every stress possible for them so they can be happy and healthy and grow fast." There are several stresses that can harm shrimp, and the Pretzers work to eliminate them. One is ammonia buildup in the tanks, which was more  of a problem when the water was new and the microbe population wasn't built up yet. Another is feeding schedules; the Pretzers are careful not to overfeed or underfeed. The shrimp are sensitive to temperature and light fluctuations; the water temperature is a steady 82 degrees, and lights are kept on overnight. "They don't like to be in the dark," Scott said, "so we leave a nightlight on for them."  

The electricity is backed up with a generator. A call center in the panel calls everyone’s cell phone until someone wakes up, in the case of an electrical outage. Then "we need to move quickly," Scott said. He figures they have about an hour with no electricity before the shrimp start to die.  One of the strengths of the Rock Creek Aquaculture Farm is that it is a true "farm to table" product. The Pretzers harvest and package the shrimp themselves, often in front of a customer. "People will come to the farm and are often able to see us harvest the shrimp right out of the water for them. It doesn't get any fresher than that." They have a specific facility, a separate room inspected by the health department, in which they meet and exceed the food code requirements, that allows them to sell the shrimp directly off the farm and to other customers. 

Their biggest customer is the general public, but Rock Creek shrimp can be found at a specialty grocery store in Ft. Calhoun, Neb. (Cure Cooking) and at two restaurants: The Venue in Lincoln and The Boiler Room in the Old Market in Omaha. Reid and Skylar man a farmer's market booth in Beatrice during the summer. Rock Creek shrimp is never frozen and is always sold only a few hours after coming out of the water.  When shrimp are harvested, the old water is saved. All the water is recycled; nothing goes down the drain. The mature water "has a lot of value," Scott said. "We don't want to get rid of it. We'll use it for years."  

Right now, the four members of the family, plus Holli's parents and Scott's parents, provide all the labor. In addition, Scott is a veterinarian. "We're a true family operation and we really like (raising shrimp) for that purpose." They are already expanding; sixteen and eighteen foot tanks are going in now. Scott and Holli would like something for their kids to come home to, if they choose, after college. "It's important for us to have something available for them," Scott said. "Not every operation can provide that." They may not limit themselves to shrimp but branch out to other fish products. "We want to concentrate on shrimp for a long time and get that down," Scott said. "But crawfish or another species of fish might be on the table."  As for shrimp, they grow Pacific Whites, which are "very, very sweet, very mild tasting, and very tender." They don't fight each other; some shrimp do, so the Pacific Whites do well in a system like Pretzers'.  

Reid, a college freshman studying agribusiness, agronomy, and enrolled in an entrepreneurship class, isn't sure what route he'll take after college. He may get a job close to home so he can help out, and he may someday return to the operation full time. "I really enjoy this," he said. "This is what I look forward to. That's why I'm putting so much time into this." He and his dad tore the feeders, gates and slats out of the gestation barn before it could be used for the shrimp, which was a big job. "I remember thinking during that time, would it be worth it?" Reid said. But it has been. "It's been a lot of fun."  

Reid and Skylar have both gotten very involved. In addition to running the farmer’s market they have taken on the job of marketing and outreach, meeting with restaurants, chefs, and taking samples. They help harvest shrimp and make deliveries.  The shrimp barn, the old gestation barn, is a perfect place for the shrimp. It's well insulated, not too old, and has sentimental value for Scott, whose ancestors immigrated from Germany to southeast Nebraska in the 1860s.

China looking to invest in aquaculture overseas


The “Tropical Countries Aquaculture Science and Technology Innovation Cooperation Group” is a little-known entity with a potentially enormous impact on future Asian aquaculture production trends. Operating out of the China Academy of Fisheries, the entity shares Chinese know-how internationally. Speaking at a major aquaculture conference in Fuzhou recently, the academy’s director, Li Jian, explained how investing overseas in agriculture and fisheries has become a new priority under the “One Belt, One Road” program, China’s foreign policy blueprint of integrating regional and Middle Eastern countries into its economy through new infrastructure, of which the ‘New Maritime Silk Road’ is part. 

China sees Southeast Asia and Africa as part of the OBOR seafood initiative, with support in seawater cage aquaculture systems producing species like yellow croaker, grouper, cobia, and silver pomfret; according to Guan Chang Tao, the chief scientist for mariculture at the Fisheries Academy. He sees China’s “outstanding resources” and “improved seed selection” as key for collaboration with developing countries in Asia and Africa.  On the same day as the conference in Fuzhou, Chinese media reported how Guinea with which it has major trade relations – was seeking to expand its freshwater aquaculture and its poultry industries to become more self-sufficient. Likewise, Ecuador, another supplier of China’s resource requirement, has cancelled import duties on many inputs for agriculture and fisheries in order to encourage more production at home.

Chinese companies have invested USD 180 billion in overseas agriculture and fisheries across 140 countries up to 2016, according to Gu Wei Bing, the senior agriculture ministry official, speaking at the Fuzhou conference. Indeed, Chinese industrial companies seeking to diversify their earnings have ploughed funds into overseas beef and soybean farms. They’ve been keen to lock down large assets and supply production back into China. 

China could now also increase output in South Asia in the same manner, according to Network of Aquaculture Centres in Asia Pacific chief Yuan Derun. According to Deun, annual shrimp output has been increasing by an average four percent globally but output in China is flat. Also attending the Fuzhou conference was Rokhmin Dahuri from the Indonesian Aquaculture Association. Dahuri said her country “very much welcomes” foreign investment in aquaculture, particular offshore. 

But there were many questions left unanswered in Fuzhou. Seeking to buy or build and operate shrimp and fish farms in Burma, Indonesia, or in Africa will require a major investment in infrastructure. Who’ll pay for the infrastructure, and how? Will developing countries take on loans from China to pay for the roads and power lines and chilled container lines that would be required to operate a significant seafood business?   If so, the model already exists, as China has pursued this strategy in other industries, whereby China adds infrastructure ultimately paid for by the host nation in either loan repayments or in resource supply arrangements. That potentially locks in developing nations into long-term and unequal supply arrangements. 

There is also the issue of control. Many of the Southeast Asian nations like Indonesia are also growing their own consumption, though average per capita incomes still lag behind those of China. It will take significant intensification to meet growing local demand and also meet China’s rising demand.  

It's also unclear if developing nations are set up to police any intensification in aquaculture. China itself is currently sending inspection teams across the country to close unlicensed aquaculture facilities and curb chronic water pollution. It took a long time for China to get this serious on their own soil,  so there is a risk that bad practices may merely be exported to other countries, where similar enforcement is unlikely. Vietnam’s Mekong Delta already has major problems brought on by intensification of shrimp and pangasius output, in large part due to growing Chinese demand for those products.  As an alternative to major expansion into developing nations, Chinese investment could also be steered toward aquaculture in aquaculture powerhouses like Norway. Norwegian banker Rude Nilsen told the conference’s attendees in Fuzhou that salmon output has to rise by nine to 10 percent per year to meet rising demand that will see China become the world’s top consumer of the product. 

Nilson hinted that he thought it can’t be long before until major Chinese investment into a Norwegian salmon production or processing business. True, capital is more plentiful from Western sources for proven projects such as salmon production. But a Chinese investment in distribution and marketing side of a Sino-foreign salmon venture would make sense.  There hasn’t been the same wave of Chinese overseas purchases in the seafood sector as there have been in soy and meat production overseas, in part because similar assets haven’t come up for sale with similar regularity but also because of the nature of corporate ownership in China’s seafood sector. Rather than state-owned giants that control the politically sensitive (for food security reasons) commodities like grain, the seafood sector is more the domain of smaller private companies whose investments are more commercial than political-strategic. Privately-owned firms like tilapia leader Baiyang and shrimp giant Guolian have been more enthusiastic about diversifying into opportunities in the domestic economy like e-commerce, information technology, education, real estate, and waste treatment. 

China is currently maxed out at 80 million tons of meat production while seafood production at 65 million tons is set to fall back to 60 million tons in 2020, according to a government plan to improve quality and focus less on quantity. There will be a certain amount of substitution: Chinese will eat less carp and switch to other species. But it seems inevitable that there’ll be an increase in volumes of seafood sourced from elsewhere.