For the past two weeks, the Utah Division of Wildlife Resources (DWR) has been filling Deer Creek Reservoir with thousands of rainbow trout that have spent the year maturing at a Springville hatchery.
On Friday morning, DWR unloaded a tank filled with about 5,000 fish into the reservoir. Another tank with a similar number of trout was emptied later that afternoon.
Various hatcheries routinely stock Deer Creek Reservoir with adult rainbow trout for recreational fishing purposes, according to Ryan Arthur, a fish hatchery specialist at the DWR’s Springville hatching facility.
Biologists will survey the reservoir, as well as other bodies of water throughout the state, to assess the ecosystem’s health and determine how many fish can be stocked without throwing the environment off balance.
“They’re basically trying to find out what’s in here currently,” Arthur said. “What species (and) what numbers.”
Based on the biologist’s findings, the wildlife resource department will then “come up with those numbers and sizes” in order to balance a productive ecosystem and healthy fishery, said Arthur.
About a year prior to stocking, DWR hatcheries will buy eggs and hatch them in warmer water than is typical for the trout’s natural habitat, which leads to quicker growth. Arthur said the Springville hatchery can grow fish at a rate of 1-inch per month.
About 70% of fish survive the hatching stage, so between 35,000 and 40,000 eggs were used to stock the reservoir with the 22,000 trout, said Arthur.
The rainbow trout released into Deer Creek Reservoir this month averaged on 10 inches, or 25.4 centimeters in length, which means they are ready for catch, according to fishing information from Northern State University.
The fish get transported inside large water-filled tanks on the back of a service trucks. Oxygen is pumped through the water to eliminate stress during transportation.
The DWR also periodically stocks other fishing hot spots and community pond in the state. A 2019 fish stocking report shows that DWR has stocked rainbow trout in Wasatch, Davis and Uintah counties, among others.
Cutthroat trout, tiger trout and channel catfish are other species that get stocked throughout Utah.
The wildlife group will continue to stock rainbow trout in Deer Creek Reservoir next week.