CASTALIA, Ohio — Close to 100,000 rainbow trout, so tiny they are not yet two-eyes-and-a-wiggle, are tucked into incubators at the state fish hatchery here, beginning a growth cycle that a year from now will have them reach 10-13 inches long. At that point, they will be ready for release into bodies of water across Ohio, providing anglers of all ages a unique opportunity to fish for this cold-water species.

The rainbows benefit from the blue-hole aquifers in the area that provide an abundant supply of 50-degree water to feed the Castalia State Fish Hatchery’s tanks and raceways. Water is also diverted from Cold Creek, which runs through the hatchery property.

Rainbow Trout Stocking from WildOhio on Vimeo.

The state recently began releasing this year’s crop of rainbows at many lakes, ponds, and reservoirs where public fishing is available. While there are resident populations of catfish, bass, crappies, and bluegills in many waters throughout the state, rainbow trout are rare since the conditions they require for year-round survival are uncommon in the Buckeye State.

The annual spring stocking of rainbow trout provides a put-and-take fishery, and the stockings often coincide with special youth fishing events. The intent is for anglers to harvest the rainbows before the heat of the summer warms the water beyond their optimum range. Olander Lake and the lake at Pearson Metropark will hold scheduled youth-only events on the dates of the trout releases.

The rainbows stocked in Ohio waters start life at a trout farm in Utah, which ships fertilized eggs overnight via FedEx, packed in Styrofoam coolers with ice. After the trout eggs arrive here at the hatchery, they are disinfected with iodine, then loaded onto trays and closely monitored as their growth cycle begins.

“They usually hatch out within a week or 10 days,” said Andy Jarrett, the superintendent at the Castalia hatchery. “After that they move into the incubators, then into small tanks inside our building for a few months before they are moved to the raceways outside. We just keep spreading them out so they have room to grow, right up to the time we load them into the trucks to be stocked around the state.”

Jarrett said the trout fry are first fed a fine mash that looks like flour, and the size of their feed gradually increases as the rainbows grow. In their final stage at the hatchery in the early spring of each year, the rainbow trout are fed pellets about ¼ inch in size. The pellets are a commercial fish food designed specifically for growing rainbow trout.

“We’ll go through about 80,000 pounds of feed to raise about 80,000 pounds of fish,” Jarrett said. “For every pound of feed we give them, we get about a pound of growth.”

The Castalia hatchery, one of six fish hatcheries in the ODNR system, raises the bulk of the rainbow trout that are released each spring. A small percentage of the trout are raised at Kincaid State Fish Hatchery in western Pike County in the southeastern part of the state and stocked at destinations in that region.

Castalia hatchery raised 90,000 rainbow trout from the early spring of 2017 until the current round of stockings started. Within the past week, trout have been stocked at Swanton Waterworks Reservoir, Delta Reservoir No. 2, and McKarns Lake in Williams County.

Jarrett said about 80,000 trout from this spring’s crop will be stocked in ponds, lakes, and reservoirs, with the remaining 10,000 stocked in Cold Creek on the hatchery property, which is opened several times a year for a limited number of fishing opportunities selected via a lottery system.

Adams Lake Trout Stocking from WildOhio on Vimeo.

With fish from the Castalia and Kincaid sites, the ODNR will stock around 100,000 rainbow trout at some 64 public lakes and ponds this spring. The first release took place at Adams Lake in Adams County in early March. The stockings continue through mid-May, with the final stocking scheduled for a section of the old Ohio-Erie Canal in Cuyahoga County.

The Castalia hatchery also produces about 400,000 steelhead annually, and those fish are stocked in Ohio’s famous “Steelhead Alley” — the Rocky, Chagrin, Grand, and Vermilion rivers and Conneaut Creek in the northeast corner of the state.

Anglers are reminded that the daily catch limit for the inland waters where the hatchery-raised rainbow trout are stocked is five trout and there is no size limit. Fishermen age 16 and older must have an Ohio fishing license to fish in state public waters.

Contact Blade outdoors editor Matt Markey at mmarkey@theblade.com or 419-724-6068.

First Published April 6, 2018, 6:00 p.m.