Three tiny logperch can be seen in the red circle (above, left). Photos by Megan Bradley/USFWS.
Hopefully you caught our article last month about spawning Logperch on station. Well, good news, the eggs we spawned are hatching and we have hundreds of Logperch fry going into a pond on station. Now, if you’ve seen other fish fry around the hatchery you might be surprised by these. The only sign that they’re in a tank is the tiny black eyes moving around in the water column. It looks a lot like you’ve sprinkled course ground black pepper, except that those tiny black specks are actively moving in the water column as the Logperch fry search for zooplankton to eat.
We were also able to use some of the Logperch adults that didn’t spawn as hosts for the federally endangered Snuffbox. In collaboration with the WI DNR we’re planning to restore Snuffbox populations in the Wolf River basin. About 20 days after the Logperch were infested we got our first Snuffbox juveniles dropping off. These first tiny babies (~150 ?m long) are growing at the hatchery as we wait for the rest of their cohorts to drop of the host fish. Hopefully these will soon go out into the Mobile Aquatic Rearing System 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 2021.
In 2019 GNFH biologists experimented with two ponds to see whether there was a difference in freshwater mussel survival from drop-off to about 6 months old in ponds that were fertilized with organic vs inorganic materials. Various water quality measures were made daily or weekly throughout the growing season, including algae (mussel food) levels in each pond, to track the effectiveness of each fertilization type. Both methods were successful, and the two ponds combined produced over 35,000 Fat Mucket (Lampsilis siliquoidea) mussels. This experiment is continuing in the 2020 season, and expanding to include two different mussel species, Black Sandshell (Ligumia recta), which use Walleye as a host, and Plain Pocketbook (Lampsilis cardium), which use Largemouth bass as a host.
In late May, hatchery biologists collected mussel larvae, called glochidia, from gravid mussels (Photo 1, gill filled with glochidia), allowed the glochidia to attach to the gills of their Walleye fish hosts in a bath exposure (Photo 2). When the mussels fully metamorphose from larvae into juveniles, they’ll drop off the fish’s gills and (hopefully!) fall into the sand in the bottom of the cage. These little mussels will start filter feeding and growing, and – later in the fall—we’ll carefully take the cage out of the pond, sift through the sand, and count and measure the juvenile mussels that were produced, comparing the outcomes between the two ponds.
Improving our ability to manage ponds for both fish and mussel production concurrently– and culture sand grain sized juvenile mussels past this first, sensitive life stage in hatchery ponds instead of in often unpredictable Mississippi River conditions—will help to make future mussel production more effective and reliable.
A smallmouth bass nest. Photo by Nick Bloomfield/USFWS.
Spring time means love is in the air at Genoa NFH. All of the brood fish we have on station, which includes Largemouth Bass, Smallmouth Bass, Bluegill, Black Crappie, Yellow Perch, Fathead Minnow, and Golden Shiner, were moved into their own ponds in March. These species are all suited for spawning in lentic environments, where there is no flow. This is in contrast to the spawning habits of fish like Walleye and Lake Sturgeon, where we need to spawn the fish manually and puts the eggs in a jar that mimics the flowing lotic environment until hatch occurs. This is much more labor intensive than the natural spawning that occurs in the ponds. All that we need to do for these brood fish is maintain water quality until it comes time to do some harvesting. Hopefully, these brood fish haven’t heard all the talk about social distancing and the hatchery will be crawling with little fish destined for areas throughout the Midwest and as future hosts for our mussel program!
Attendees listen to Frog Monitoring Volunteer, Ben Johnston, as he describes the mnemonics of frog calls. Photo by USFWS
36 people made their way to the interpretive center on Saturday, March 7 to learn about Wisconsin frog calls. Ben Johnston, volunteer frog monitor for Wisconsin DNR, taught audience members 11 frog calls and 1 toad call. Participants had an opportunity prior to and after the event to view living frogs, make a frog life cycle, or make a jumping frog. A huge thank you to Ben Johnston for providing such an interesting presentation! By Raena Parsons
Walleye nets are hung on a fence in spring. Photo by USFWS.
The weather has not able to make up it’s mind this year at Genoa, we have warmed up several times and then received snowstorms right after! In between the snow and rain, hatchery staff have been busy getting the station ready for the spring field season. The buildings have been sprayed down, cleaned up, tanks are getting set up, spawning ponds were set up with air stones and screens and nets are getting prepped for the river. As soon as tanks were set up in the Sturgeon Building, we began draining our host fish pond after it finally warmed up enough to melt most of the ice on the pond, allowing us to harvest the fish. Every fall, Genoa National Fish Hatchery will harvest the production ponds, collecting enough fish first for the mussel program and then any fish beyond that will be used for fish requests or to help out our state partners. The host fish then will either be used immediately for mussels that brood in the fall or will hang out over the winter to be used in the spring or summer the following year. Because of space constraints at the hatchery, the fish will over winter either in the mussel building, sturgeon building or in one of the hatchery ponds. The most of the fish kept in the mussel building will be the ones inoculated in the fall with either Winged Mapleleaf or Washboard Mussels. Access to the colder pond water helps to keep the channel catfish closer to their normal temperatures, reducing stress on the fish and the growing mussels over the winter. The sturgeon building only has access to well water over the winter, so the golden shiners and largemouth bass will spend their time in in there. They are much better suited to the more constant water temperatures. The remaining channel catfish not used, smallmouth bass and walleyes will spend the winter in the pond. These species survive much better following the normal cooling down and warming up of the water outside, and the extra space reduces stress on the fish as well. By Angela Baran-Dagendesh
Every year the mussel program at Genoa places mussel cages in the waters of the Upper Mississippi River from the St. Croix River down to Dubuque, IA. Some of these cages will spend multiple summers in the river before they require repair, but the undeniable truth is that eventually the environment wins and the wire cages rust to the point they must be repaired. On February 26th,, March 4th and March 11th a total of 18 volunteers from the Friends of Pool 9 and Friends of the Upper Mississippi gathered in the shop at the hatchery to repair damaged mussel cages. A large pile of cages needed repair this year. Our first day was dedicated to preparing cage tops and bases for new wire and plywood. This meant that on days two and three the group quickly got to work riveting new wire onto empty cage top frames and plywood to bases. These volunteers have been repairing cages at Genoa NFH for over 10 years. When the dust had settled, over the 3 days, volunteers had stripped and repaired 34 tops and bases. For their efforts the volunteers were treated to a lunch of burgers and all the sides. A good time was had by all and the hatchery staff is very appreciative of all the many hours that were saved by this dedicated group of volunteers. Thank you! By Megan Bradley
The Great River Road Interpretive Center has a new exhibit to call its own. We are proud to be able to display the history of the construction of Lock and Dam 8 on the Mississippi River built just up the road from the hatchery at the Genoa Wisconsin site. This pictorial history is being displayed in the local history room of the Center, and was compiled by local historian Anne Muirhead. Included is the method of diverting the mighty Mississippi to allow for construction, the construction of the retaining dike and spillway, the construction of the locks using historic steam shovels, and pictures of the local crews of the Works Progress Administration (WPA). The WPA was a depression era work program initiated by the Roosevelt Administration to put people back to work on public works projects across the country. Also included in the pictures is an image of a steam powered paddleboat moving down the River, the historic mode of transportation at the time. Paddleboats were used due to their low draft, or profile in the River, that allowed them to move through shallow areas safely without running aground in the pre-lock and Dams reaches of the River. Once the navigation system was constructed and in use, a navigation channel of 9 foot depth is now maintained, allowing the current barges to transport their goods on the River. The dike at Genoa is over 3.3 miles long and the dam structure is 934 feet long. The lock can accommodate barges with lengths of over 500 feet long, and typically moves over 16 million tons of cargo down the River annually. The Great River Road Interpretive Center was built as a collaborative effort with the National Scenic Byways Program and the U.S. Fish and Wildlife Service, and its mission is to educate and inform Great River Road travelers on the unique geography, natural history and local history of the region, while instilling a conservation message to the public. For more information about the center, please see our Facebook site, or feel free to call the station at 608-689-2605. By Doug Aloisi
By Megan Bradley, Genoa National Fish Hatchery
Freshwater mussels are host
specific, not just any fish will do. Snuffbox, a federally endangered species
of mussel, depend on Logperch, a large darter that can grow up to approximately
six inches and is found across the Midwest to transform their larvae into
juvenile mussels. This fall a biologist with the Columbia Environmental
Research Center in Missouri let us know that he’d had a great year raising
Logperch in his ponds and we were able to pick them up in November. Five
hundred Logperch arrived on station and were moved into quarantine. Logperch
are a favored fish species because they learn very quickly to associate food
with people and are charming when they beg for their breakfast with their
rostrums (noses) out of the water. The Logperch are here to act as hosts for
Snuffbox collected from the Wolf river system in the late fall. The hatchery is
hosting three female Snuffbox collected from the Wolf River for the winter.
Biologists from Genoa National Fish Hatchery and Wisconsin Department of Natural
Resources plan to infest the Logperch in the spring and then drop off and grow
the juveniles for a couple of years before reintroducing the species back into
Wolf River streams where the species has been extirpated
On Saturday February 15 volunteers with the Coulee Region Audubon Society led a family-friendly bird walk at Genoa National Fish Hatchery (NFH). 14 people of various ages made the trek to the hatchery to participate in the Great Backyard Bird Count (GBBC). The GBBC is a worldwide citizen science project that takes place over four days every February where participants collect data on wild birds and can see results in near real-time. Participants counted 25 Bald Eagles, 6 Common Mergansers, 6 Killdeer, 1 Wilson’s Snipe, and 1 Peregrine Falcon during a 45 minute walk at the hatchery. A huge thank you goes out to the Audubon Society volunteers, Dan and Roger. This event would not have been possible without you!
Winter is typically a time where the hatchery staff can begin to
repair the damage to our buildings and equipment, as well as add improvements
that our maintenance staff would not be able to do during the production
season. This winter was no exception, with maintenance necessary to equipment
crucial to the operation of our offsite mussel rearing trailer. Also included
was the installation of a new iron filter for removing iron from culture water
before it is used on our walleye egg incubation battery. This raises the
capacity of our previous iron filter by over 300%, which will allow us to
increase water flows within the system to reduce fungus growth and increase egg
survival. Also included within the system is the installation of a three
phase pump with a variable frequency drive, which should save on the hatchery’s
electric bill this coming spring. The station’s mussel trailer is a good object
lesson on how hard life can get in a trailer down by the River. It started its
life as a converted tool trailer back in 2009. In 10 years the flooring was
developing soft spots and one of the interior walls was harboring a fungi
species. After its 10th season in the field, the floor was fixed, walls were
purged of mold and fungi and painted and new waterproof LED lighting was
installed. Culture and UV systems were also maintained and readied for the
coming spring deployment. The trailer is deployed at a local Corps of Engineers
Campground which is adjacent to the mighty Mississippi. The River is the
trailer’s water source, bringing with it the tiny microscopic particles the
young mussel larvae need to survive, and is crucial to the success of Genoa’s
mussel program. Now the only thing needed is the changing of the season. Even
with the snow cover, the days are growing longer, and the staff is growing more
anxious to put their new and renewed equipment through its paces. Come on