Every year, Norfork National Fish Hatchery plays a critical role in supporting Arkansas’s trout production, raising 550,000 rainbow trout destined for Jim Hinkle State Fish Hatchery in Mammoth Spring. Most of these fish—about 450,000—are transferred at an average length of six inches, while another 100,000 are moved when they reach eight inches. But before any fish can make that journey, they undergo an essential step: vaccination for Enteric Redmouth disease (ERM), a serious bacterial infection known to occur in Jim Hinkle’s water supply.
To ensure the trout remain healthy, each fish is vaccinated at Norfork NFH prior to transport. This spring, during late May and early June, hatchery employees and volunteers completed the immense task of vaccinating roughly 300,000 rainbow trout. Though only about four inches long, these young fish collectively weighed nearly 7500 pounds—an impressive reminder of the scale of the operation.
The vaccination process itself is efficient and well‑practiced. Nets full of trout are immersed in a protective solution for just 30 seconds, allowing the fish to absorb the vaccine before being returned to their raceways. Now fully vaccinated, these trout are preparing for their next chapter, with transfers scheduled in June and September.
The work is demanding, but it reflects the dedication of the hatchery team and volunteers who help safeguard the health of Arkansas’s trout populations—and ensure these young fish arrive at their next home ready to thrive.
