Winged Mapleleaf takeoff for the fall

Hatchery biologists joined partners from the Park Service the Minnesota-Wisconsin Ecological Services Field Office, U.S.G.S., and the University of Minnesota to search for displaying Winged Mapleleaf this year. Over the past 6 years we’ve experienced different patterns of flow and temperature across the fall and this year is different still, with very low water levels and persistent warm temperatures.  The Winged Mapleleaf responded and have been active early, but the warmer temperatures seems to be acting to slow down their displays. We found the first female in full display in the shallows on Thursday 9/22, an exciting start. We’ll be out on the river every other day for another week or so to ensure we find enough females to infest all of our host fish. We have many plans for any mussel larvae, from collaborative projects with U.S.G.S., to producing juveniles for our own culture at the hatchery.
By: Megan Bradley

A Winged Mapleleaf in full display. She is ready to infest her host fish, the mantle magazine is the grey protuberance sitting at the center of the white to grey plate of inflated mantle that she will not pull back when disturbed. Her glochidia, or larvae have been released into her mantle cavity in preparation for a fish mouthing at the magazine. If none arrives they’ll be ejected into the river after a day or so and she’ll burrow back down into the river bottom. Photo Credit: Megan Bradley/USFWS.

Snuffbox Drop off for Wolf River Restoration

Newly transformed juvenile Snuffbox crawling in dish among sand. Photo: Megan Bradley/USFWS.

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 original plan was to collect Wolf River Logperch, the Snuffbox’s host, and infest them on the side of the river but unfortunately that didn’t go as planned. Instead hatchery Logperch were infested and the females returned to the river. The first tiny babies (~150 ?m long) are dropping off now. These new juveniles will be stocked into the river shortly after drop off to approximately mimic the effect of the free-release.

Snuffbox is a favored species as it’s the only widespread member of its genus, all of which 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. By: Megan Bradley

Streamside Mussel Culture Trailer Up and Running for the Summer Growing Season

Every spring, as the early flood waters on the Mississippi River recede, we eagerly await time to launch the MARS (Mobile Aquatic Rearing System) mussel culture trailer. Placement of the trailer at Blackhawk Park, a USA Corps of Engineers facility right on the Mississippi River just south of the Hatchery is a wonderful long-term collaboration that allows us to greatly improve growing season success for many species of juvenile mussels. The trailer is cleaned and repaired at the Hatchery over the winter, then in late May or early June is moved to the Park, river water is pumped in to the trailer, filtered and UV sterilized, then piped to culture tanks. Outflow water is again UV sterilized and returned to the slough just down-stream.
The MARS trailer emptied and cleaned for over-winter storage at GNFH. Zach repairing electrical components that control the drum filter, which reduces sediment and potential pests from the inflowing water to the trailer. Rearing tanks being positioned in the trailer. Photo: Beth Glidewell/USFWS.
Juvenile mussels produced in previous years that need another summer of culture are placed in the culture tanks when the trailer is first set up, others will be placed in trailer tanks as they are produced over the summer. We currently have Washboard, Plain Pocketbook, and southern Higgin’s Eye new juveniles, and soon we’ll have Rock Pocketbook juveniles ready for culture in the trailer. Later this summer they’ll be joined by a northern population of Higgin’s Eye, Sheepnose, Salamander Mussel, and Giant Floater mussels. Older juveniles requiring an additional year of growth in the trailer this year include Fat Mucket, Spectaclecase, Sheepnose and Higgin’s Eye.

Larger juvenile mussels being added to trailer culture tanks.


Newly transformed juvenile mussels that will be placed in culture tanks with fine mesh screens. Photo: Megan Bradley & Beth Glidewell/USFWS.









These juvenile mussels fill up almost every tank in the trailer, so Genoa NFH staff check water flow and aeration, water temperature and basic water chemistry daily throughout the growing season. We check the filtration and UV systems and make repairs as needed, keeping the system running smoothly all season.
By: Beth Glidewell

Genoa National Fish Hatchery Biologist is Recovery Champion


Higgins Eye Pearlymussel in sand. Photo: USFWS.



Megan Bradley, a mussel conservation biologist at the Genoa National Fish Hatchery in Genoa, Wisconsin, recently received news that she will receive the coveted 2022 FWS Midwest Region Recovery Champion Award for her work with federally endangered freshwater mussels in the Upper Mississippi River. Megan worked with other agencies, tribes and national and international partners to improve the status of several species of imperiled mussels through her efforts to map suitable habitat, create new populations, monitor released mussels and planning and implementing programs to raise and release endangered species like the Higgins Eye Pearlymussel, the Winged Mapleleaf mussel and the Spectaclecase mussel.
Megan has also been instrumental in establishing the cost of replacing mussels affected by environmental contaminants through the NRDA process, enhancing the ability to recover damages and restore these species. She has also been responsible for helping to produce multiple year classes of a number of species of mussels for release into spill impacted areas, some of which included the Endangered Higgins Eye Pearlymussel. Congratulations Megan! We are proud to serve alongside of you!
By: Doug Aloisi

Megan in dive gear holding a mussel in one hand. Photo: USFWS.

Kid’s Fishing Day at Genoa NFH: A Great Community Event


Kids and their parents from all over the tri-state area of Iowa, Wisconsin and Minnesota gathered at the Genoa National Fish Hatchery for our 19th annual Kids Fishing Day on May 14th this spring. The event, which is sponsored by the hatchery Friends Group, the Friends of the Upper Miss, and the Fish and Wildlife Service Fisheries field stations in the La Crosse area, was attended by over 175 people this year.

The children and their parents/guardians first walked through a set of four learning stations. Station 1 was on boating safety taught by the hatchery’s Maintenance Worker Zach Kumlin, at Station 2 mussel identification and conservation by the hatchery mussel biologist Megan Bradley, at Station 3 was fishery regulations by U.S. Fish and Wildlife Service game warden Joshua Bauer of the Upper Mississippi River Wildlife and Fish Refuge Office in Savannah, Illinois and Station 4 offered fish identification and fishing techniques by hatchery lead biologist Nick Bloomfield.

After an hour of learning more about fish and conservation, the kids were allowed to put their newfound knowledge to practical use with a two hour open fishing event on a stocked hatchery pond. Most of the children went home with their five fish limits. The event is very popular with Friends Group members and local Volunteers alike, as they serve as mentors to the children and assist with fishing tips, gear and bait selections, and demonstrate casting. A light lunch was then provided by our Friends group.

This year’s event was also made possible by a donation in honorarium by the Bay family, in memory of Earl Bay. Patriarch Earl Bay was an avid fisherman, being especially fond of fishing with the classic cane pole. Through the family’s generous donation, gifts were distributed to every child that attended. These included the attendee’s choice of the classic cane pole, a fishing rod and reel combo, or a tackle box. Many thanks to the staff of the three La Crosse area FWS fisheries offices, sponsors, volunteers, and Friends of the Upper Miss for making this event possible. Making memories outdoors will reinforce the value of our natural resources to the future generation. It is also hoped that events such as these will build a sense of ownership into the outdoors, and plant the seeds of conservation stewardship to ensure that their children can enjoy all the outdoors has to offer.

Above: This lucky angler shows off a “whopper” 14 inch rainbow trout that she landed at the Genoa NFH Kid’s Fishing Day. Credit: Erica Rasmussen/USFWS

Spring 2022 Hine’s Emerald Dragonfly Hatch Complete 



The Hine’s Emerald Dragonfly (HED) eggs that were housed at Genoa National Fish Hatchery over the winter began hatching in late March and by late May, 445 eggs had successfully hatched. These eggs arrived on station last November and were kept at cool, stable temperatures all winter. Eggs are kept by female line in sample cups of clean water and are checked frequently for fungal growth or other problems. Water is exchanged every other week to maintain good dissolved oxygen levels.

As temperatures began to warm outside this spring, we warmed the egg chamber slowly over several weeks and then above the critical hatching temperature of 42-43 °F. Cups are checked daily during the warming period for newly hatched larvae. As larvae hatch, they are pi petted out of the egg cup into their own specimen cup filled with about 20 milliliters of clean water of the same temperature water.

These new juvenile cups are allowed to slowly warm to room temperature in the mussel building, where they are fed zooplankton two to three times per week. Pond water that is pumped into the mussel building for fish housing and mussel culture is also filtered through a series of mesh screens, and zooplankton that are between 55 to 300 microns are retained, concentrated, and ‘fed’ or pipetted into each juvenile cup. This mixture of rotifers, cladocerans, copepods and other naturalized pond zooplankton make great Hine’s Emerald larvae food, and also feeds young of the year fish cultured in the various ponds at the hatchery.

The juvenile dragonflies will be housed in these cups until early to mid-June when they’ve (hopefully) grown large enough to be moved to screened cages or ‘s-cages’ that can be kept in larger, flow-through tanks in the dragonfly trailer all summer. Stay tuned for pictures and updates from this next stage of HED culture!

Above: HED eggs stored at stable temperatures over winter. The eggs are housed at about 39 degrees Farenheit from November to March. Credit: Beth Glidewell/USFWS

Genoa National Fish Hatchery Biologist is Recovery Champion


Megan Bradley, a mussel propagation specialist at the Genoa National Fish Hatchery in Genoa, Wisconsin, received the Midwest Region recovery champion award for her work with endangered freshwater mussels in the Upper Mississippi River. Megan worked with other agencies, tribes and national and international partners to improve the status of several species of imperiled mussels through her efforts to map suitable habitat, create new populations, monitoring released mussels and planning and implementing programs to raise and release endangered species like the Higgins eye pearlymussel, the winged mapleleaf mussel and the spectaclecase mussel. Megan has been instrumental in establishing the cost of replacing mussels affected by environmental contaminants, enhancing the ability to recover damages and restore these species.

Above: Congratulations to Megan on receiving the Recovery Champion Award! Credit: USFWS


SATURDAY, MAY 14, 2022
8:30 AM—12:00 PM
Genoa National Fish Hatchery
Join staff from the 3 La Crosse area U.S. Fish and Wildlife Service Fisheries Offices and our Friends Group, the Friends of the Upper Mississippi for a day of fishing fun!
This popular annual event is for children 5-12 years old who are accompanied by a parent or guardian. The event begins with hands-on learning sessions about fishing techniques and conservation, then children are allowed to fish in a stocked hatchery pond.
Bait will be supplied, with no outside bait allowed due to biosecurity concerns.
Or call: 608-689-2605

Banner Year for Walleye Spawning

After spending a week out looking for Northern Pike, it was time to get back to our bread and butter: Walleye spawning. 2020 and 2021 were both strange years for different reasons. In 2020, we weren’t allowed to set nets due to ththis year, and Mother Nature did not disappoint. We set 62 hoop nets out on April 4th and got the season started. The first couple of days were slow, as expected, but spawning activity quickly picked up steam and resulted in several record breaking days during the week of the 11th. By the 15th, our entire egg battery of 108 jars were all full of eggs! Our season lasted less than two weeks but we were able to get all we needed for our requests and we will be able to hatch many extra to send back to the river.
By: Nick Bloomfield


net full of fish.



Walleye eggs in incubation jars

USFWS worker holding a walleye





Walleye eggs being poured into incubation jars