Hundreds of yellow ovals offset the brown and green coloration of each female brown trout ready to spawn at the Manchester Fish Hatchery. The splashes of color are signs that trout spawning season is in full swing.
Brown trout are currently being spawned. Brood trout are brought to the hatchery from French Creek in Allamakee County. They are held at the hatchery across two spawning cycles then released back in French Creek, supplementing earlier generations of brown trout.
All brown trout are stocked as 2-inch fingerlings. “Anglers like these ‘wild’ stream raised fish. They are harder to catch than our put-and-take stocked fish,” explains Mike Steuck, Iowa DNR fisheries supervisor for interior streams. “Many of the public streams have lots of brown trout in them.”
Brook trout, Iowa’s only native trout, give up their eggs in late October and early November. Eggs are taken streamside from wild South Pine Creek Brook Trout, fertilized and taken back to the Manchester Fish Hatchery to be raised and stocked as 2-inch fingerlings in June.
“As a part of DNR’s Brook Trout Restoration Program, we’re working to re-establish populations of Iowa ‘wild’ brook trout in streams with suitable habitat and excellent water quality,” said Steuck.
Rainbow trout, the backbone of Iowa’s trout program, take up much of December and January. Roughly 750,000 eggs will be collected this season.
Crews check for ripe female broodstock once a week. After a quick sedative bath to calm them, each big trout is held firmly over a plastic bowl, as one of the workers rolls a hand down her belly to force out a stream of orange-golden eggs—up to 4,000 to 6,000 per fish. Mixed in quickly is the milk-white sperm from two males. Water is added to activate the eggs and sperm allowing fertilization to occur.