From Engineer to Fish Farmer

Paige Balcom is a mechanical engineer who studied the feasibility of employing an aquaponic system at the Lukome Center in northern Uganda while on a nine-month Fulbright research grant. She immersed herself in the Ugandan culture and enjoyed the challenges of engineering in Uganda. Paige recently returned to the United States and is starting the mechanical engineering M.S./PhD program at UC Berkeley with a National Science Foundation Graduate Research Fellowship and Berkeley Chancellor's Fellowship.

Here is the first in a series of Paige’s fascinating posts.

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In December 2016, we were busy with the fish ponds. We started off with draining one of the big ponds and harvesting all its fish. It was so exciting to see what I’d been talking about for weeks actually materialize! It was a tiring, muddy day, but so worth it.

ChildVoice hired a bunch of community guys as day laborers, and they started by unearthing the pipe and digging a drainage ditch. Once the pipe cover was removed, water gushed out. Then it was time to get some fish! Pairs of guys hopped in the water and dragged mosquito nets along the length of the pond, trying to catch as many fish as possible. It’s harder than it sounds—those fish are pretty smart and very fast!

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When the guys made it to the far side, we’d take the nets and sort the fish. The big ones we kept for eating, and the small ones we threw into the other two ponds. There were some big ones, but a lot of the fish were quite small because a wild strain of tilapia has invaded the ponds. The red-tailed fish are male, and they grow well. The white-bellied fish are females of the same strain, but the fish with black stripes are like weeds that invade the population and don’t grow well. Unfortunately, we had a lot of black-striped tilapia.

As the water drained, it became a race against the clock to capture all the fish before the pond went dry. Everyone jumped in and tried to grab fish! Some held a long black netting and walked it across the length of the pond to corral the fish while the rest of us tried to capture them with nets and our bare hands, which wasn’t easy—they were fast, and their fins were spiky! Soon all the water drained from the corners of the pond, leaving fish flapping in the mud. We waded through the ankle-deep muck trying to scoop up the critters before they suffocated.

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Finally, most of the fish were captured, and we prepared to enjoy our labor! Tracey, the catering class teacher, and some of the girls cleaned and gutted fish and began frying them in oil. They were really tasty! I learned that you start by eating the hard tail of the fish and continue down all the way to the eyeball, which wasn’t as bad as I was expecting.

The community guys began digging out all the mud on the bottom of the pond. This pond sludge, comprised of rotting organic matter, needs to be removed because it creates an oxygen-sealing layer that prevents good bacteria from growing on the bottom and instead promotes anaerobic bacteria, which release toxic hydrogen sulfide. After removing the sludge, we limed the pond to sterilize it and kill any pests before restocking.

Finally, we started pumping water back into the pond! With the help of the District Fisheries Officer, we located a fish supplier with good strains, so we could restock the pond with healthy, fast-growing tilapia! We’re also going to get some catfish that will eat the stunted tilapia we already have that won’t grow.

Next Step, Aquaponics

One form of aquaponics is growing plants on rafts, so one day Knight, the head plant farmer, and I tried an experiment. In the U.S., people usually use Styrofoam insulation board for rafts, but that’s expensive in Uganda and only available in the capital of Kampala. Instead, we tried to make a raft out of locally available materials. 

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One rainy day I was staring at the grass roofs of our huts and had an inspiration. “Dried grass floats!” So Knight cut some long grass and let it dry for a couple of days, then we attempted to make a raft. Neither of us had any idea what we were doing, so we made it up as we went. We tried gathering small bundles of grass and tying them together—it held together; we just hoped it would float! 

Finally, we were ready to test our contraption! We laid it in the water and held our breath—it floated! We stuck some collards, tomatoes, and peppers between the grass bundles and prayed our raft would last overnight. 

The next morning, my hopes were dashed. The raft was starting to sink, the sides were coming undone because the fish were eating the grass, and by afternoon the plants were all wilting and falling over from the intense sun. Our experiment wasn’t doing so well, but maybe it could be salvaged with some design changes. I grabbed some empty water bottles and tied them along the bottom of the raft—it bobbed up and our buoyancy problem was solved!

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This raft experiment perfectly portrays my experience designing an aquaponic system in Uganda. Some days are filled with excitement and anticipation as I make progress, while other days are filled with disappointment as I go back to the drawing board. Usually I feel like I have no idea what I’m doing—my limited experience helping with an aquaponic system for a year at university didn’t prepare me to design a whole system by myself. I’m an engineer—I don’t know fish and plants!

It’s a journey of ups and downs, but whenever I grow discouraged, I only have to listen to the girls’ heartfelt songs during nightly prayers to remember that God called me here for a purpose, and He will give me the strength and skill to accomplish His plan.