Friends of the Upper Mississippi

The last couple years at Genoa NFH, we’ve been experimenting with different methods of growing out juvenile freshwater mussels along with Largemouth Bass in productions ponds. This field is relatively new without a lot of past research to draw from. The pond environment is quite different than the river environment that our riverine species are accustomed to, but we’ve had some successes to go along with the failures. We’ve been able to point to temperature and pH as two potential water quality variables that may have limited success in the past. To combat that, we’ve installed real-time monitoring instruments that are able to transmit data wirelessly to our computers. This will allow us to respond more quickly as issues arise to mitigate for those issues and hopefully keep our baby mussels happy. Stay tuned for the next chapter of this story this fall!
By: Nick Bloomfield

Zach installing the control box at Pond 14 North

In collaboration with the WI DNR, GNFH is planning to restore Snuffbox populations in the Wolf River basin. Last fall, WI DNR biologists spent some chilly dive days aggregating males and females to ensure that brooding females could be found this spring. The first tiny babies (~150 ?m long) are expected soon. Soon these will go out into the Mobile Aquatic Rearing System at Blackhawk, the U.S. Army Corps Park, to eat the natural food in Mississippi river water (bacteria and algae) and grow large enough to overwinter well at the hatchery for release in 2023.
Snuffbox is a particularly favorite species as it’s the only widespread member of their genus, all of whom catch their host fish. This unexpected behavior begets novel characteristics (‘toothed’ shell edges, the capacity to sit open, exposing their body cavity to the environment) making these species fascinating to observe. How these behaviors and morphologies, or physical characteristics in biology jargon, have developed and been maintained is fascinating to consider. We look forward to sharing more information about this species and others reared at the hatchery as our buildings open to the public and events develop in the coming years.

The group of broodstock Snuffbox, freshly tagged and ready to be returned to the river.

Snuffbox use log perch as hosts.

After a missed year of spawning Walleye on Pool 9 in 2020 due to the pandemic, we were back in action this spring. A strange spring it was weather wise for us in Western Wisconsin. We put our nets in on April 5 and started spawning fish on April 6. An unseasonably warm spell following a cold snap had temperatures rise 10 degrees from 44 F to 54 F in only three days, peaking at 58 F a couple days later which blew right through the typical spawning temperatures (around 45-50 F). A cold snap brought temps back down into the mid 40’s the following week. The fish seemed to be confused as well.
We never saw the typical “bell curve” of spawning activity slowing rising to a peak before slowly falling off. Numbers of ‘ripe’ fish were inconsistent until falling to near zero by April 22 when we pulled our nets. We likely missed a few of the early spawners over Easter weekend with the significant warm up, but we were able to send millions of eggs to our partners, stock our ponds for production, and return hundreds of thousands of eggs and fry back to the river.
By: Nick Bloomfield

Zach mixing milt with freshly collected eggs

Nick and Chelsea collecting newly hatched fry for stocking. Photos: Beth Glidewell/USFWS.

Orey displaying an adult brook trout that was part of the 2017 egg collection effort

The newest additions to Genoa National Fish Hatchery arrived on station in January. About 50,000 fertilized Brook Trout eggs were sent from our sister hatchery at Iron River. Hatching began almost immediately upon arrival in mid-January and all the fry were hatched out by the end of January. Staff have been busy caring for the eggs and fry ever since. These fish will live in the safety of the quarantine building until they have passed multiple fish health inspections. The treatment system in place in the Quarantine Building will keep the rest of the hatchery protected from any pathogens until we can ensure that there are none, at which point we can move them to a bigger rearing space. Once these fish are big enough to ensure a high survival rate in the wild, they will be stocked into the Lake Superior basin to help boost populations of Coaster Brook Trout.
The story behind the origin of these new arrivals begins in October of 2017. Eggs were collected from remnant populations of Coaster Brook Trout from the Isle Royal area and raised at Genoa NFH. This process was repeated the following year, and another batch grew up in the hallowed raceways of Genoa NFH. These fish weren’t destined for the wild, however. These two lots were destined for the FWS broodstock program and were sent back to Iron River NFH. Fast forward to 2021 and holding two distinct lots of broodstock that were becoming sexually mature, staff at Iron river NFH were able to cross them with minimal likelihood of relatedness between parents. These little guys will grow up in the same raceways their parents did, but they are destined to ultimately help grow the population along the shores of Lake Superior so Americans can enjoy them for generations to come.
By: Nick Bloomfield

An exciting offshoot of the Genoa National Fish Hatchery (GNFH) role in the Maumee River (OH) Lake Sturgeon restoration work is to be able to contribute fish to Michigan’s Lake Huron basin restoration program in cooperation with the Michigan DNR. Lake sturgeon are broadcast spawners, meaning they literally release hundreds of thousands of eggs per female in order to achieve reproductive success. This is due to the many predators that wait for a meal of sturgeon eggs every spring. Due to this large number of eggs that are released, spawning crews generally take more eggs than needed from specific females in order to maintain strain specific restoration programs.
This has specifically paid benefits on the western shore of Lake Huron where the GNFH joins forces with many partners such as the Michigan DNR, the Ontario Ministry of Natural Resources and Forestry, Alpena Fish and Wildlife Conservation Office and others to collect eggs annually from fish captured in the Upper St. Clair River. The fish are held and eggs collected at a local commercial fishery that graciously allows us to use their holding facilities to restore this species to the Great Lakes watershed. In the years 2017, 2018 and 2019 a total of 2,059 Lake Sturgeon fingerlings were stocked into tributaries which flow into the Saginaw Bay area in Lake Huron.
These efforts are already producing results with fish being captured and released in waters devoid of sturgeon for the last 100 years. This after only a stocking effort of 3 year classes and a little over 2,000 fingerlings! We hope to contribute many more year classes and their important genetic contribution in order to ensure both adequate numbers of fish are able to sustain the new population, and significant amount of genetic variation is available for the population to remain viable. However, it is heartening that although such a small number of fish were released, they are already being seen and documented in habitat that has been devoid of the species. We find hope that this is a sure sign that our efforts and the efforts of our partners have a hand in the return of this magnificent species.
By Doug Aloisi

An angler holds lake sturgeon caught in the Saginaw River. Fish was released