Shrimp Grading Machine another Tool for Commercial Fishermen

James Kerian (left) and Lance Nacio

One of the most time-consuming aspects in shrimp harvesting could be eased through mechanization, and a North Dakota company with ties to Louisiana’s commercial crawfish industry hopes to aid in that process.

For more than 50 years, Kerian Machines Inc. has manufactured equipment for sorting fruits and vegetables. In the 1990s, they expanded with crawfish sorting machines. Now, they hope to assist the shrimp industry with the Kerian Speed Sizer.

Louisiana Sea Grant and LSU AgCenter extension agent Thomas Hymel and shrimper Lance Nacio approached James Kerian, president of Kerian Machines, about modifying their crawfish grading equipment to work with shrimp. The original speed sizer was on Nacio’s boat, but there were issues, so they moved it from the boat to the dock.

A prototype sizer was developed and successfully demonstrated in 2020 at the Louisiana Fisheries Forward Summit. During the topsy-turvy economy of the COVID-19 pandemic, Kerian continued to refine the machine, addressing issues like how to modify a sorter designed be used on land to be used aboard a shrimp boat, and reduce corrosion and rust from saltwater exposure.

Louisiana shrimper Clay “CJ” Theriot, who uses the grader, says it has been beyond helpful in his operation when catch sizes fluctuate. “Sometimes the catch is large and sometimes it’s not,” he said. “We may not have enough hands to sort the catch, and that’s where the grader comes in.”

The current model can sort up to 3,400 pounds of shrimp per hour. This speed allows Theriot to grade his shrimp more efficiently in a market that requires a uniform size. This attracts more buyers who will pay a premium price. In Theriot’s experience, the machine can process about 24,000 pounds in seven hours — work that would take days to complete manually.

The shrimp grader itself consists of a roller system where shrimp move forward and fall between gradually increasing gaps – allowing the shrimp to be sorted based on size. This grader can be adjusted to sort three different shrimp sizes.

“We have developed this project to the point where we can offer equipment that will sort shrimp quickly, accurately, gently and reliably — while providing a low-maintenance, rugged machine,” said Kerian.

Kerian Machines is currently developing smaller units that will fit on the smaller, inshore vessels. It’ll be made from aluminum, instead of stainless steel, and available at a more consumer-friendly price point.

“Prior to this machine, there wasn’t a size sorter for head-on shrimp,” said Hymel. “The industry is all about tails and peeled meat, but to be able to do direct marketing with a head-on shrimp, there really wasn’t any equipment out there that could be used. This changes that.