Rock Creek Aquaculture Farm

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. “I grew up as a kid with this building. I put a lot of work into them, and these barns put me through college.”  

The shrimp farm is open to the public for tours on Sunday afternoons from 1-3 p.m. and by appointment for group tours on other days during the week. For Scott, it’s one of the most rewarding parts of the job. They’ve seen about 2,000 people visit, and Scott likes that. “Even if they don’t like shrimp, people enjoy the process. They’re impressed with the operation, how it’s run and how we grow shrimp. Then they try it and contact us and say, it’s hands down the best they’ve ever had. That part is rewarding to me.”  

Shrimp can be preordered through the website, http://www.rockcreekshrimp.com or by calling the farm (402.875.1567), and can be picked up seven days a week, with advance notice.