Sustainable shrimp farming in the Midwest

Karlanea Brown calls them her “divas.” Chef Fred Eric calls them “the popcorn of the seas.”  Scientists call them litopenaeus vannamei. I call them dinner.  And you know them as shrimp. But the shrimp we profiled on this week’s TechKnow are in a class all their own.

Six hundred miles from the nearest ocean, nestled in a patchwork of corn and soybean fields in tiny Fowler, Indiana is RDM Aquaculture – a groundbreaking indoor saltwater shrimp farm. It’s so successful and so environmentally positive that it is teaching the scientists a thing or two.

Karlanea Brown and her husband Darryl were in the hog business, when one day, Darryl came home and said “How about shrimp?” Like a bolt of lightning, Karleana knew instantly this would be the rest of her life. When our host Phil Torres asked if the Browns knew anything about raising shrimp, they both barked back, “Not a thing.” But, they sure do now.

With two-dozen basic backyard pools as indoor growing tanks, they’ve perfected a system with zero waste, no chemicals (except for fish food, salt and baking soda) and only the same water for the past five years. The lack of waste and chemicals and new water with their terrific success rate is what makes them so special. With most of the industry coming in at about 65% survival rate, the Browns have a 90% survival rate, at least until it gets to your plate.

In stark contrast with her tiny wards, Karlanea has a big and bubby personality, a perpetual smile and a hearty laugh. But, it wasn’t always so. When they first started in the shrimp biz, they lost 75% of their stock. Now, after 5 years, Karlanea has a knack for ratios: alkalinity, nitrates, nitrites, oxygen levels, salinity and temperature. The Browns test their water at least once a day, nine tests in all and adjust accordingly. Not enough alkalinity, toss in the right amount of baking soda, not enough salt, sprinkle some in, need some more nitrites, kick up the bacteria. Day after day she’s kept the shrimp growing and her water working. Not bad for a college graduate in fashion.

She and Darryl have confounded the experts by figuring out the delicate balance all on their own. And they certainly need to know because they run their place with known as a “heterotrophic biofloc system.”

The Browns sell 70 percent of their shrimp to growing farms. About 500 pounds go to “walk-ins” for $18 a pound. They can’t keep up with demand. So, they’ve sold their know-how and some of that fine bacteria to about 2 dozens start ups in the US and as far away as Switzerland. But the proof is in the eating.

Karlanea let Phil fish out 40 from the tank for our dinner. That’s about a pound. Despite Phil’s rugged adventures, his shrimp netting had a bit of a Keystone Cops quality to it.  The shrimp had his number, either eluding his net or literally jumping for their lives. Eventually, Phil filled the bucket.

In our story we talked with Fred Eric, a chef who owns Fred 62 in Los Angeles. He’s the guy who calls shrimp the popcorn of the sea – easy to crunch, highly addictive. He told us that he likes shrimp because they become full of the flavors they’re cooked with. But he might change his tune a little if he was in Fowler sitting in the Browns kitchen, listening to fresh shrimp sizzling in the pan with just a little oil.

Now, I’m not a big shrimp fan. But, those little divas were the sweetest taste I’d never experienced from a shrimp. The proof of how good? Our four-man team ate every… last… one. If only Phil could’ve netted us more!

A heterotrophic system means an animal feeds on organic matter. Organic matter in this case means shrimp poop, bacteria, microalgae, molted shrimp shells, and even dead shrimp. The biofloc system has been called “counter-intuitive” because it calls for all that organic matter to accumulate, rather than be filtered out. As long as the water is aerated enough to keep the “floc” moving around in “suspension” and the shrimp are feeding on what they need and the bacteria are feeding on their waste it all keeps going. So, the water may look murky brown, but it’s like the nectar of the gods, the shrimp gods. Darryl says it’s matured like a fine wine. He says he’s doesn’t raise shrimp, he raises bacteria. Karlanea calls herself “the guardian of water” rather than a shrimp farmer.

The RDM compound is divvied up into 3 parts: the nursery where the “post larvals” arrive at 11 days old about the size of an eyelash, the intermediate tanks where they grown until three months and the final growing tanks where they’re fattened up for dinner. Karlanea pulled a few out to check. They don’t look anything like those rolled up, headless commas from the bag. (The store shrimp heads are removed because, yup, shrimp rot from the head after two days) The Browns shrimp are long and translucent. You can see their heart beating. You just have to do it carefully cause they get mad, really mad. And they’ve got these horns that can really draw blood. Ask Phil.