Wild About Utah

September 14, 2026September 14, 2026

Don’t Move a Mussel

Quagga Mussels Exposed at Lake Powell Courtesy & Copyright Utah Division of Wildlife Resources, Phil Tuttle, Photographer — Quagga Mussels Exposed at Lake Powell
Courtesy & Copyright Utah Division of Wildlife Resources, Phil Tuttle, Photographer

You’ve heard the phrases, “Don’t move a mussel,” (spelled m-u-s-s-e-l) and “Stop aquatic hitch hikers.” If you have ever transported a watercraft, ranging in size from a paddle board to wake surf boat, you’ve probably been annoyed by the inconvenience of stopping at mandatory boat check stations for invasive species watercraft inspections. The threat is real and I hope this segment will make you a believer in inspection stations.

Let’s backtrack.

The opening of the St. Lawrence Seaway in 1959 allowed cargo ships to bypass the rapids on the St. Lawrence River and enter Lake Ontario. From there ships could access Canada’s Welland Canal, which also uses a series of locks to allow ships and barges to bypass Niagara Falls and access the rest of the Great Lakes. Proponents of the St. Lawrence Seaway sold the project on the grounds that it would turn the Great Lakes into a North American “Mediterranean” by transforming cities from Rochester, New York to Duluth, Minnesota into global ports.

They got what they wished for, but with a twist. “Salties,” or oceangoing cargo ships, traveling from the Mediterranean, Black, and Caspian Seas, emptied their ballast tanks in Great Lakes ports as cargo was loaded. In June of 1988 the first documented zebra mussel was found in Lake St. Clair—a small lake (in comparison to the Great Lakes) where the St. Clair River pools about halfway along its journey from Lake Huron to Lake Eire. This single, fingernail-sized mussel signaled a catastrophe. By the end of 1989, invasive zebra and quagga mussels were found in all five Great Lakes.

Zebra Mussel (Dreissena polymorpha) vs Quagga Mussel (Dreissena rostriformis bugensis).
Courtesy USGS, Wetland and Aquatic Research Center, Amy J Benson, Photographer — Zebra Mussel (Dreissena polymorpha) vs Quagga Mussel (Dreissena rostriformis bugensis).
Courtesy USGS, Wetland and Aquatic Research Center,
Amy J Benson, Photographer

Zebra and quagga mussels are mollusks—soft-bodied invertebrates housed in hinged, two-part shells. They contain a muscular “foot” that allows them to move twelve to fourteen inches per hour—but that’s not how they travel most efficiently. Zebra and quagga mussels can produce a million eggs per year, that hatch into microscopic “veligers” which can swim efficiently for several weeks before their shell begins to form, sinking them to the bottom. Once a mature zebra mussel finds a suitable place for a home, the foot forms an epoxy-like bond with hard surfaces, making them difficult and expensive to remove from ship hulls, water intake pipes, docks, locks, and hydro-electric power infrastructure.

Zebra mussels thrive in water less than about fifty feet deep and on hard surfaces. Quagga mussels thrive in soft lake bottoms in water as deep as 500 feet. Together these invasive mollusks wreak havoc on aquatic ecosystems where they are most vulnerable—the bottom of the food chain.

Razor sharp zebra and quagga mussels filter microscopic nutrients from the water, This makes lakes clearer, while stripping them of nutrients aquatic species depend upon. By 2009 phytoplankton levels in the Great Lakes were diminished by 90% compared to pre-mussel levels. Clearer water makes for easier fishing for predatory birds and clearer water allows sunlight to penetrate deeper into lakes, warming them up faster and creating prime conditions for toxic algae blooms. Algae blooms deplete the water of oxygen and create ideal conditions for botulism, which then causes massive waterfowl die-offs. All of this has happened in the Great Lakes in a viscous cycle set in motion by zebra and quagga mussels.

Invasive mussels were found in Lake Mead in 2007 and in Lake Powell in 2013—transported from the Midwest recreational boats. What has happened in the Great Lakes can—and is—happening in the west.

Pristine waters that could be harmed by Aquatic Invasive Species
Courtesy & Copyright Eric Newell, Photographer

So, the next time you have to wait in line at a boat-check station, know you are doing the right thing. Clean, drain, and dry your paddle boards, kayaks, whitewater rafts, fishing boats, and wake surfers before transporting them to other waterways and lakes. It only takes one contaminated watercraft to put the rest of the lakes and rivers that we all love in peril.

I am Eric Newell and I am wild about Utah’s lakes and rivers.

Credits:

Images: Quagga Mussels exposed at Lake Powell, Phil Tuttle, Photographer, Utah DWR
Boating, Eric Newell, Photographer
Featured Audio: Courtesy & Copyright J. Chase and K.W. Baldwin.
Text: Eric Newell, Edith Bowen Laboratory School, Utah State University & Lyle Bingham, Bridgerland Audubon Society

Additional Reading:

WildAboutUtah pieces by Eric Newell, https://www.upr.org/people/eric-newell

Egan, Dan, Zebra Mussels’ Takeover of the Great Lakes, January 2, 2019, https://www.discovermagazine.com/zebra-mussels-takeover-of-the-great-lakes-2626

What are Invasive Mussels?, Invasive Mussel Collaborative, Great Lakes Commission, https://invasivemusselcollaborative.net/about/mussel-facts/#:~:text=They%20were%20first%20discovered%20in,at%20the%20bottom%20of%20lakes

Howard, James, When Zebra Mussels Made the Great Lakes “Clean”, October 8, 2025, https://jameshoward.us/2025/10/08/when-zebra-mussels-made-the-great-lakes-clean

Zebra Mussels, BB-17, Environmental Fact Sheet, New Hampshire Department of Environmental Services, 2026, https://www.des.nh.go v/sites/g/files/ehbemt341/files/documents/2020-01/bb-17.pdf

Map of Lake St Clair, The Great Lakes, Google Maps, https://www.google.com/maps/place/Lake+St+Clair/@44.6782974,-87.146707,1192993m/data=!3m1!1e3!4m6!3m5!1s0x88253a42a07febbd:0x679a153523440e7c!8m2!3d42.4356504!4d-82.6915429!16zL20vMDJnMzdn?entry=ttu&g_ep=EgoyMDI2MDkwOS4wIKXMDSoASAFQAw%3D%3D

Great Lakes St. Lawrence Seaway Development Corporation, https://greatlakes-seaway.com/en/

Leahy, Colleen, Quadrillions of invasive mussels are damaging the Great Lakes, documentary shows, Wisconsin Public Radio, February 28, 2025, https://www.wpr.org/environment/drebert-melnick-documentary-quagga-mussels-great-lakes#:~:text=The%20quagga%20mussel%20has%20infiltrated,are%20felt%20throughout%20lake%20ecosystems.

Book recommendation:

Egan, Dan, The Death and Life of the Great Lakes, W. W. Norton & Company, 2017, https://www.betterworldbooks.com/product/detail/the-death-and-life-of-the-great-lakes-9780393355550

September 7, 2026September 12, 2026

BirdCast Dashboard Shows a Peak Need for Dark Skies: Dim the Lights for Birds at Night

Milky Way above Chesler Park Canyonlands National Park Courtesy US National Park Service, Emily Ogden, Photographer — Milky Way above Chesler Park
Canyonlands National Park
Courtesy US National Park Service,
Emily Ogden, Photographer
Canyonlands is one of many parks in southern Utah with the International Dark Sky Park designation

BirdCast Migration Dashboard
https://dashboard.birdcast.info/
Courtesy BirdCast, The Cornell Lab of Ornithology
Cornell University

BirdCast Migration Dashboard https://dashboard.birdcast.info/ Courtesy BirdCast, The Cornell Lab of Ornithology Cornell University — Milky Way above Chesler Park
Canyonlands National Park
Courtesy US National Park Service,
Emily Ogden, Photographer
Canyonlands is one of many parks in southern Utah with the International Dark Sky Park designation

BirdCast Migration Dashboard
https://dashboard.birdcast.info/
Courtesy BirdCast, The Cornell Lab of Ornithology
Cornell University

Songbirds migrate at night to avoid predators, air turbulence, and daytime heat. Down here on the ground we are unaware of the miraculous and essential voyagers flying up to 10,000 feet above us, but thanks to dedicated scientists collaborating for years on end we have free access to the data and graphs of these massive population shifts. The BirdCast Dashboard uses weather radar to track bird migrations, providing real time data showing peak migrations at the website dashboard.birdcast.info.

Did you know that World Migratory Bird Day is celebrated in May and October? Those are the peak months for spring and fall migrations, and the magnitudes of those flocks are considerable. Two thirds of songbirds migrate at night, and on the evening of Sunday, May 15, 2022, one million one hundred and fifty one thousand five hundred (1,151,500) birds crossed Cache County, Utah! Yes, 1,151,500 birds crossed Cache County, Utah, in one night!

It’s important to know when migrations are occurring because skyglow from artificial lighting causes bird disorientation and millions of bird fatalities each and every year. The declining bird population is problematic for many reasons, not least of which because some of the most intrepid travelers like the three-inch-long Rufous Hummingbird, which travels 3,900 miles each way from Alaska to Mexico, are keystone species with ecosystem services such as pollination and consumption of pests such as aphids and mosquitoes.

The Bobolink travels 12,500 miles to and from southern South America every year – those imperiled birds breeding at the west end of Logan may travel the equivalent of 4 or 5 times around the circumference of the earth throughout their lifetime. They come to Cache Valley for the habitat, stay to raise their young, and then head back to their distant winter feeding grounds.

A few top-notch steps toward bird-friendly living include the prevention of light trespass and skyglow, especially from 11 p.m. to 6 a.m., March – May, and August – October. Close curtains to prevent the indoor light from escaping, and avoid blue light outdoors – choose warm white or amber lights, and shield light bulbs to direct light downward. Motion-activated light bulbs are a great way to safely light the way while cutting down on unnecessary outdoor lighting, especially since there’s no clear scientific evidence that outdoor lighting reduces crime. Excess light, on the other hand, is a crime, and light trespass is an enforceable infraction. Light pollution is harmful to humans and deadly for birds.

Logan Mayor Holly Daines signed a Proclamation to Dim the Lights for Birds at Night because reducing skyglow and light trespass saves energy and birds by reducing the often fatal disorientation caused by artificial light.

Dark Skies are filled with bright stars, so by jingles, what say we all “Dim the lights for birds at night!”

I’m Hilary Shughart with the Bridgerland Audubon Society, and I am Wild About Utah!

Credits:
Images: Milky Way above Chesler Park, Canyonlands National Park, Courtesy US National Park Service, Emily Ogden, Photographer, https://www.nps.gov/media/photo/gallery-item.htm?id=286169fc-2bab-40e0-bf8b-a13b5170aeb3&gid=2ADECB87-1DD8-B71B-0B09BD0B18C96667
Screenshot: BirdCast Migration Dashboard, Courtesy BirdCast, The Cornell Lab of Ornithology, Cornell University, https://dashboard.birdcast.info/
Featured Audio: Courtesy & Copyright © Kevin Colver, https://wildstore.wildsanctuary.com/collections/special-collections/kevin-colver
Text: Hilary Shughart, President, https://bridgerlandaudubon.org/
Additional Reading: Hilary Shughart and Lyle Bingham, https://bridgerlandaudubon.org/

Additional Reading

WildAboutUtah pieces by Hilary Shughart, https://wildaboututah.org/author/hilary-shughart/

Miller, Zach, Dark Sky Parks, Wild About Utah, Nov 2, 2020, https://wildaboututah.org/dark-sky-parks/

Leavitt, Shauna, Natural Quiet and Darkness in our National Parks, Wild About Utah, May 6, 2019 & August 3, 2020, https://wildaboututah.org/natural-quiet-and-darkness-in-our-national-parks/

Rask, Kajler, Dark Skies, Wild About Utah, Jan 1, 2018, https://wildaboututah.org/dark-skies/

Dark Skies, Bird-Friendly Living, Advocacy, Bridgerland Audubon Society, May 2022, https://bridgerlandaudubon.org/our-projects/advocacy/bird-friendly-living/dark-skies/

Dim the Lights for Birds at Night, Bridgerland Audubon Society, May 3, 2022, https://bridgerlandaudubon.org/our-projects/advocacy/bird-friendly-living/dark-skies/

International Dark Skies Association, Utah Chapter, https://utah.darksky.ngo/

Welzbacker, Hannah, Tracking a Night-Time River of Birds, Cool Green Science, The Nature Conservancy, April 13, 2021, https://blog.nature.org/science/2021/04/13/tracking-a-night-time-river-of-birds/?fbclid=IwAR18LKCQUmSlb-hHM1u4FXfVe-GqyWTwiPx91obUQbq2uB9kcPU2djlCnlk

BirdCast Dashboard, The Cornell Lab of Ornithology, Cornell University, https://dashboard.birdcast.info/

Global Bird Collision Mapper, Fatal Light Awareness Program (FLAP) Canada, https://birdmapper.org/app/

Lowe, Joe, Do Hummingbirds Migrate?, American Bird Conservancy, September 12, 2019, https://abcbirds.org/blog/do-hummingbirds-migrate/

Bobolink (Dolichonyx oryzivorus), “Bobolink is one of the few grassland-dependent species of concern that breed in Utah”, Utah Division of Wildlife Resources, April 20, 2020, https://wildlife.utah.gov/pdf/sensitive_species/birds_bobolink_2020.pdf

Bobolink (Dolichonyx oryzivorus), All About Birds, Cornell Lab of Ornithology, Cornell University, https://www.allaboutbirds.org/guide/Bobolink

Lighting, Crime and Safety, International Dark-Sky Association, https://www.darksky.org/light-pollution/lighting-crime-and-safety/#:~:text=There%20is%20no%20clear%20scientific,cost%20a%20lot%20of%20money

2022 Proclamation “Dim the Lights for Birds at Night”, https://bridgerlandaudubon.org/dim-the-lights-for-birds-at-night/

The use of the “by jingles” exclamation is in homage to Warren Dahlin’s moving Moth Radio Hour story “Open My Eyes”, in which he “makes a friend who stays with him in life and in death.” Heard on Utah Public Radio (5/28/22), The Moth, https://themoth.org/radio-hour/squeaky-wheels-1

Owens, Avalon & Cochard, Précillia & Durrant, Joanna & Farnworth, Bridgette & Perkin, Elizabeth & Seymoure, Brett. (2019). Light pollution is a driver of insect declines. Biological Conservation. 241. 108259. 10.1016/j.biocon.2019.108259. https://doi.org/10.1016/j.biocon.2019.108259

August 31, 2026September 12, 2026

Mollusks in Utah, then and now

Click to view this piece on UPR.org — Mollusk shells along the southwest shore of Bear Lake, Rich County.
Courtesy Utah Geological Survey (UGS),
© Mark Brunson, Photographer

For many people in northern Utah, there’s nothing better than a warm afternoon with family and friends at Bear Lake. You can splash in the shallows, bask in the sunshine, and stroll along the shoreline while marveling at a centuries-old legacy of ancient mollusks.

Wait, what??! Ancient mollusks, 800 miles from the ocean? Yes, it’s true.

For years, when visiting Bear Lake, I’d be fascinated by snail shells strewn along the shore just above the waterline. I always wondered why we could find thousands of shells but would never see a live snail.

Click for a larger view: Mollusk shells along the southwest shore of Bear Lake, Rich County. Courtesy Utah Geological Survey (UGS), Copyright Mark Milligan, Photographer — Mollusk shells along the southwest shore of Bear Lake, Rich County.
Courtesy Utah Geological Survey (UGS),
© Mark Milligan, Photographer

Mollusk shells along the southwest shore of Bear Lake, Rich County.
Well, it turns out that Utah is home to numerous species of live snails, but the shells we see beside Bear Lake have been there for nearly 10,000 years! They’ve lasted this long because they’re preserved by the calcium chemistry of a lake that’s fed by springs and groundwater beneath the limestone crags of the Bear River Range. Many years ago, researchers from the Smithsonian Institution identified six species of snail and one species of clam amongst the Bear Lake sands, all of which thrived in a bygone era when the lake was 30 to 50 feet higher and much bigger.

The snails that occupied those shells may have died out, but they have living relatives today. Scientists say that the group of invertebrates in the phylum Mollusca includes more than 85,000 recognized species, including clams and oysters, barnacles and limpets, snails and slugs, squids and octopuses. Some can even be found in our arid, landlocked state of Utah.

If you travel the highways of Utah and surrounding states, you’ve seen signs warning against a mollusk species that we don’t want in the state: the quagga mussel. These clam-like creatures have turned up in Lake Powell and we don’t want them in other lakes and reservoirs. They’ve become a nuisance in other states, clogging pipes and water lines, and competing with native fish for food. Once they become established, removing quagga mussels or the closely related zebra mussel can cost many millions of dollars. That’s why Utah has set up boat-inspection stations across the state to try to keep them out.

Another mollusk that many people would like to be rid of is the common garden slug – also called the grey field slug and known to malacologists as Deroceras reticulatum. Slugs don’t seem much like oysters or squids, but they’re basically just snails that have evolved to get along without a shell.

Less visible are the many other species of mollusks found in our state. A few years ago, biologist Eric Wagner published the Utah Mollusk Identification Guide with descriptions of 139 species of snails, slugs, clams, and mussels found within the borders of our state. Just one year later, Eric and a colleague, Christy Bills from the Natural History Museum of Utah, published an article reporting three additional species – two snails and a slug – that had not been seen in Utah before. Undoubtedly there are more that no one has noticed yet.

Just about all of Utah’s mollusks are cryptic – a term biologists use to refer to creatures that are hard to notice. Many are quite rare. One example is the Kanab ambersnail, a dime-sized creature found only at a large spring in Grand Canyon National Park and some small ponds near the town of Kanab, Utah. Others, like the freshwater mussel called the Western Pearlshell, can be found across the West but their populations are declining.

These creatures may not be obvious, but they’re part of what makes Utah’s wild nature so varied and wonderful. Losing any one of them would be a tragedy.

I’m Mark Brunson, and I’m wild about Utah’s wild creatures, no matter how cryptic.

Credits:

Images: Bear Lake Shells, Courtesy & Copyright Mark Brunson, Photographer, as well as Shells on the Bear Lake Sand, Courtesy Utah Geological Survey, Copyright Mark Mulligan, Photographer.
Featured Audio: Courtesy & © J. Chase and K.W. Baldwin and Anderson, Howe, and Wakeman
Voice & Text: Mark Brunson, https://www.usu.edu/experts/profile/mark-brunson/
Additional Reading: Mark Brunson, https://www.usu.edu/experts/profile/mark-brunson/ & Lyle Bingham, Bridgerland Audubon Society

Additional Reading

Mark Brunson’s Wild About Utah archive: https://www.upr.org/people/mark-brunson

Beautiful UTAH: The wonderfully weird world of mollusks. The Payson Chronicle (Oct. 6, 2021). https://paysonchronicle.blogspot.com/2021/10/beautiful-utah-wonderfully-weird-world.html

Carey, Trevor. 2018. The Conservation of the Kanab Ambersnail. University of California-Davis Center for Watershed Sciences. https://cwseducation.ucdavis.edu/class/116/conservation-kanab-ambersnail

List of mollusks of Utah facts for kids. https://kids.kiddle.co/List_of_mollusks_of_Utah

National Park Service. Western Pearlshell. https://www.nps.gov/articles/000/western-pearlshell.htm

Palacios, Patsy, Chris Luecke and Justin Robinson. 2007. Paleo-biology and paleo-hydrology of the Bear Lake Basin, Utah. https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1592&context=nrei

Utah Division of Wildlife Resources. Collection, importation, and possession of fish, mollusks, and crustaceans in Utah. https://wildlife.utah.gov/cip

Wagner, Eric, and Christy Bills. 2024. Three gastropod species reported in Utah for the first time. https://scholarsarchive.byu.edu/wnan/vol84/iss1/12/