Moving Day

Life as a fish might be less than dramatic most of the time. Kibble-shaped feed flings onto the surface of their tank several times a day, which causes a whirring frenzy of snarfing. But otherwise it’s mostly swimming round and round in a land of blue, coming up to see what’s happening, and going down to take a fishy snooze. Our striped tilapia don’t have to worry about the weather outside or avoiding predators—it’s really pretty cush.

Of course, once the fish are large, there are harvest days, when the dreaded net enters to take them away. It’s all part of making room for the ranks of littler tilapia ready to join the operation and secure a constant supply of nutrient-dense fish manure for feeding the system plants. Happy, hungry fish means happy, vibrant lettuce, Swiss chard, bok choi, tomatoes, and all sort of other yummy crops.

The fish arrive via UPS from a breeder downstate. Packed in a Styrofoam crate in oxygen-stuffed bags of water inside. Called “fingerlings,” they’re about the size of a small minnow (0.9 of a gram), darting about. Tilapia can be shipped in this manner, so long as the journey stays warm enough and they’re back in a circulating tank within 24 hours. On a rural UPS rout, though, this isn’t always possible. Fortunately, we’re able to meet the driver in town to pick up the precious package early and rush the fishes home.

Using a goldfish net, I carefully scoop out a few into a bucket of water, where Mom and I try to count them.

“Six.” They’re wriggling and splashing, their side fins twirling.

“No, seven…I think. Could you all stop swimming and hold still!?”

Counting fish doesn’t seem to be our forte. But after warming the bags to the same temperature as the tanks and carefully adjusting the pH to minimize shock, the introduction process begins. By the end of the long process, 100-110 tilapia fingerlings are cruising at the bottom of their nursery tanks, hoping the dreaded blue net stays far away.

The nursery system is a micro-sized version of the main aquaponics system. This way, all their fishy needs are met and we can monitor that they haven’t brought in a new disease that shouldn’t be mixed with the other fish. Also, because the fish are so small upon arrival, it would be a great tragedy if they escaped through the drainage holes and were suddenly everywhere! Renegade fish!

But eventually, those little babies grow up to be chubby teenagers (about 50 grams) and are ready to move into a vacant tank in the main system. That means moving day for the fish, which was yesterday’s project.

Mom and I drain out as much water as possible, making it easier for us to reach down into the chest-high tanks and harder for the fish to jump out onto the floor. They crowd on the bottom, their dark, slippery backs dashing about, visible against the azure blue of the tank. I don’t know if the fish understand what’s coming next, but they certainly know that the day’s routine is far from normal.

With a small fishing net (a considerable step up from the goldfish net), I sneak in and scoop up a few. “Three!” I call out as we again attempt to keep count of the population number. Their wet, silvery tummies flash in the light as I invert the net into the 300-gallon tank. Zoom, they head for the bottom, as far away from me as is fishily possible.

But the next scoop has too many to count from the outside, with big ones and little ones all wriggling about. I set the bottom of the net in the tank and reach carefully in to snag one at a time. “Four, five, six.”

It’s not easy to hold onto a fish. They’re all wiggle and twist, and the spines on the back can prick a palm to bleeding, which always seems to get infected. I carefully slide my hand along the fish’s head to lay back the spines, then lift under the gill where the jaw allows some firmness. Ploop, over the rim of the net goes the tilapia, joining the rest of the newly released crew.

Some of the fish are fighters, thrashing and splashing, sending water everywhere. Soon, my glasses are spattered, my hair is wet, my face is dripping, and my shirt is drenched. Come on you guys, you’re not even very big yet! “Thirty six, thirty seven.”

The first nursery tank empties out at 50 fish, though we’ll check with the scope later to make certain no one was hiding in an invisible corner in a round tank. If there is too much discrepancy of size, the bigger fish will eat the littler ones. With a new batch coming in on Thursday, we’ll want to make sure that we didn’t leave any of these teenagers behind.

Then it’s onto the next tank, bucketing down the water level so that I’ll be able to reach the fish below. They’re starting to run out of room in the tank, there’s so much fish, which is a good sign that they were ready to move into the bigger tank.

Splash, splash, and here we go. A net-full emerges. It’s moving day on the farm for fish, as the cycle of life continues. And even though they begrudge the experience and pout in the lower half of the tank most of the rest of the day, the tilapia soon lighten up and begin exploring their world. I’ll bet this morning they’ll be getting ready to attack the food again, which is a sure sign of fishy happiness.

As for me, it’s time to wipe my glasses and change into something dry—brrr. See you down on the farm sometime.