Friends of the Upper Mississippi

PVC cages with mesh end caps housing Hine’s Emerald Dragonfly larvae. These cages are arranged in flow-through culture tanks in the Dragonfly Trailer at GNFH. Photo: Beth Glidewell/USFWS.

Larvae in culture cups floating in tanks, ready to be packed up for transport.

After spending the growing season in culture tanks in the dragonfly trailer, Hine’s Emerald Dragonfly larvae were checked, photographed for measurement, and packed up for transport during the first week of November. 267 larvae were first placed into pvc tube, mesh screen capped cages in early June. Culture tanks in the trailer allow a fresh supply of pond water and ample zooplankton prey for the larvae, while also creating a semi-controlled culture space where dissolved oxygen, water flow rate and temperature can be monitored and controlled all summer. A mid-season check showed an 81% survival rate for the first stage (cages with 400-500 micron mesh) and an 89% survivorship for second stage cages (the larvae had grown enough that 1mm mesh was sufficient)

The 193 surviving larvae were placed in 100 ml specimen cups for transport. Colleagues from the University of South Dakota (USD) and the Forest Preserve District of DuPage County, IL—partner institutions for the Hine’s Emerald project—came to GNFH and securely packed up the specimen cups for transport back to their institutions for over-winter storage. Water temperatures had dropped to near 40 °F, so larvae had slowed down metabolically and had sufficient oxygen in these cups for transport and will be checked weekly or bi-weekly all winter. Hine’s Emerald larvae typically require several growing seasons to reach a sufficient size that they’ll emerge as adults. These larvae will be cultured for another growing season and their size will be monitored so they can be placed in culture cages that allow both aquatic larval and aerial/perching adult stages well before emergence occurs (the non-aquatic adults very much do not want to be in a mesh cage under water!).
As we said goodbye to one cohort of dragonflies, the next round was arriving. Researchers at USD brought next year’s round of eggs to distribute between GFNH and the Forest Preserve District (with eggs also over-wintering in the USD labs, we’ve got our eggs in 3 baskets…). These eggs will be kept at cold and stable temperatures (3-4°C) until early April, when we’ll begin to warm them and start next year’s hatch.
By: Beth Glidewell

Propagating mussels is difficult for lots of reasons, but their dependence on a live host fish always creates a challenge. Fish survival at the hatchery is usually strong, but the more you handle them, the more prone they are to disease since you damage the protective mucous coat or even dislodge scales and infesting fish with freshwater mussel glochidia involves a lot of handling. Propagation becomes even more arduous when the glochidia transform over months, rather than weeks since you have to keep your fish healthy over long, cold months when they don’t eat much and they’d rather be buried in the mud in a deep river hole. Successfully producing juvenile Winged Mapleleaf, a federally endangered mussel, depends on this over-wintering, as does the Washboard, North America’s largest native freshwater mussel.
Less successful seasons see the loss of these host fish due to disease, and therefore the loss of Winged Mapleleaf larvae, but treatments are required to manage illness, while not harming the developing glochidia. One of our graduate pathways interns has taken this topic on as her graduate thesis work. She is treating Washboard-infested Channel Catfish weekly with typical fish disease treatments to determine whether they decrease the number of quality of juveniles dropping off the fish in the spring. Many treatments have been tested in bass infested with Plain Pocketbook to confirm that they don’t impact the new juveniles, but none have been tested for multiple uses, or over multiple months. Being able to manage disease in Winged Mapleleaf-infested Channel Catfish will make a difference in the success of the recovery program for this species and others across the country.
By: Megan Bradley

Volunteers play a vital role in supporting the U.S. Fish and Wildlife Service’s mission: working with others, to conserve, protect and enhance fish, wildlife, and plants and their habitats for the continuing benefit of the American people. The Genoa National Fish Hatchery relies on volunteers to manage the bookstore in the Great River Road Interpretive Center and provide information to the general public about the facility, assist with lake sturgeon and brook trout coded wire tagging, pond harvesting in the spring and fall, mussel cage repairs and tagging of freshwater mussels. Volunteers donate their precious time in helping us at the hatchery complete our mission and for that we are extremely appreciative. Even amid a pandemic, volunteers stepped up to the plate to lend a helping hand while following federal guidelines on mask mandates and social distancing. A combination on 62 volunteers tagged over 60 thousand lake sturgeon and brook trout and donated 229 hours of their time, 12 volunteers harvested fish and mussel ponds and tagged mussels for 25 hours, and 6 volunteers teamed up to staff our visitor center bookstore and volunteered 275 hours while hosting over 1500 visitors from July-October. In just four months of the year, hatchery volunteers donated 529 hours ~ equivalent to 66 eight-hour workdays!!! From the Genoa Staff: “We appreciate all of you for donating your time to make the USFWS mission successful and for supporting our great aquatic resources.” By: Orey Eckes

Volunteers tagging Brook Trout and Lake Sturgeon. Photo: Erica Rasmussen/USFWS.

Volunteer tagging Fatmucket mussel. Photo: Erica Rasmussen/USFWS.

A hatchery tour can be a great destination to explore and learn new things. This was recently the case for the Schiesher sisters. The four sisters live in different locations throughout the United States and every year they get together to explore a new area. This year they elected to explore the driftless region of Western Wisconsin. One of their stops was at the Genoa National Fish Hatchery. They took a tour of the Great River Road Interpretive Center, stopped at the wonderful gift shop, hiked the nature trail and around the ponds and of course, stopped to feed our brook trout from the floating dock! It is so great to see the excitement on everyone’s faces as the fish jump, scrambled and fought to get some food. They walked away with gifts in hand and knowledge and memories to share with others. They wrote very interesting A++ in the address book. Email or call to set up your tour today! By: Erica Rasmussen
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Beautiful views along the Wisconsin River. Photo: Beth Glidewell/USFWS.

In October, Genoa NFH mussel biologists joined colleagues from the Wisconsin DNR in a search for Salamander Mussel broodstock on the Wisconsin River. We were very lucky to have mild weather this far into the fall, leading to a day of spectacular scenery on the river and several gravid female mussels collected. These females will be kept over the winter at the hatchery- the cold water temperatures signaling the females to keep their larvae safe in their marsupial gills- a portion of the gills that are structured to incubate eggs as they develop into mature larvae. In the spring, we’ll remove the larvae from the female’s gills, allow them to attach to gills of Common Mudpuppy, and hopefully produce juvenile Salamander Mussels.

The use of the Common Mudpuppy- the only non-fish host used by North American freshwater mussels- makes this species unique. The Mudpuppy’s large filamentous gills and strictly aquatic nature makes them a very similar functioning host to fish species. They also move between local microhabitats, taking mussel larvae with them, just like a fish host. Both Salamander Mussel and Common Mudpuppy utilize similar habitats- protected spaces under large rocks in swift but stable areas of large rivers. These habitats have always been somewhat rare, but have been severely impacted by human activities leaving both of these species increasingly imperiled and in need of conservation focus. WI DNR biologists will be back in the river at this site and others in the spring looking for additional gravid females next spring propagation efforts- stay tuned for updates from this project!
By: Beth Glidewell