Iowa DNR Manchester Fish Hatchery staff Dan Rosauer, Aaron Schwartzhoff, Eric Bailey and Garald Rivers were recently honored by the Iowa Driftless Chapter of Trout Unlimited with their Stream Stewardship Award.
The Iowa Driftless Chapter of Trout Unlimited recognizes outstanding contributions to Iowa trout conservation, education and public access. Manchester Fish Hatchery staff have helped raise and stock over 192,000 native brook trout fingerlings into more than 60 northeast Iowa streams.
“If anglers catch a wild brook trout in northeast Iowa, there’s a good chance it’s there because of the dedicated current and past staff of the Manchester Fish Hatchery,” said Michael Siepker, Northeast Iowa regional fisheries supervisor.
Brook trout restoration efforts began in 1994, when a genetically-distinct strain of healthy brook trout unique to Iowa was found in South Pine Creek, a tiny spring creek buried between lush vegetation in eastern Winneshiek County. These brook trout have likely called this place home since before the first European settlers came to the region.
To save this fragile native Iowa species, hatchery staff transported 900 fertilized eggs back to the Manchester Hatchery in a coffee cup. That first year, 160 fingerlings were produced.
DNR fisheries staff take special care when spawning South Pine brook trout. Instead of spawning the fish in the hatchery, like they do with domesticated strains of rainbow trout, technicians go on site around the first week of November and spawn the fish on the river bank and bring the eggs back to the Manchester Hatchery. More than 51,430 fingerlings were stocked into 34 streams during the first 23 years of restoration work.
The eggs are hatched and raised to about two inches in size, and reintroduced into other streams to grow up wild. “Our capacity to restore brook trout is limited to the number of eggs we can collect from South Pine,” explains Siepker. “We have to balance collecting as many eggs as possible with minimizing impacts to the South Pine Creek brook trout population.”
To increase egg availability, Manchester Hatchery staff started to hold wild fingerlings at the hatchery and raise them to adults in 2016. By 2018, milt from wild South Pine males was used to spawn females at the hatchery. Captive brookies were maturing one to four weeks later than wild fish, so hatchery staff developed a protocol to store milt for the later spawns.
Siepker estimates that there are more than 500 miles of coldwater streams in northeast Iowa. Not every mile is suitable for brook trout, but there are many miles where brook trout can be restored. “Iowans deserve to have these beautiful native brook trout in any place that we can have them,” Siepker said.
The ability to sustain brook trout indicates great stream health, as they are an indicator species of northeast Iowa’s streams, demanding the coldest and cleanest waters to prosper. DNR staff consider water temperature, current fish populations, and stream habitat conditions before stocking trout in a stream.
Brook trout are stocked into a new stream with suitable habitat three consecutive years to try to establish a strong and healthy population. About three years after the last stocking, fisheries staff sample the stream to see if there are young brook trout in the stream.
The process to determine where this colorful trout that is part of Iowa’s history is stocked is a complex process that involves a lot of partners. The areas that are determined viable to reintroduce brook trout have undergone significant conservation work to reduce bacteria and sediment. In some streams, it’s been decades since trout have been able to naturally reproduce and survive.
Trout lay their eggs in gravel so clear conditions are critical - sediment can smother the eggs and prevent young trout from hatching. Healthier streams have been able to support larger and naturally reproducing trout populations. “You have more robust trout populations with improved water quality and habitat,” said Siepker.
Spring is a great time to explore Iowa’s coldwater streams. Anglers can find wild brook trout in 11 streams that are open to public fishing. Find the list of streams on the DNR Trout Fishing webpage at www.iowadnr.gov/trout.