As an avid angler and Utah resident, I’ve always been fascinated by the Great Salt Lake. This enormous lake in northern Utah is well known for being very salty, but does this extreme environment actually support any fish species? I decided to do some research to find out what fish are in the Great Salt Lake and how they manage to survive.
The Great Salt Lake has a salinity level that can reach up to 27% – that’s 8 times saltier than the ocean! Needless to say, these conditions pose a major challenge for most freshwater fish. Only a handful of fish species have adapted in special ways to withstand the high salt content.
A Closer Look at the Great Salt Lake’s Unique Ecosystem
Before diving into the fish, let’s understand why the Great Salt Lake is so salty in the first place This lake is a remnant of the massive prehistoric Lake Bonneville. Over millennia, the water evaporated away leaving behind high concentrations of minerals and salts
The lake covers about 1,700 square miles near Salt Lake City. But it’s very shallow, with an average depth of just 13 feet There are two main arms – Bear River Bay in the north and Farmington Bay in the south
Three rivers flow into the lake, bringing in fresh water. But the lake has no natural outlet, so water can only leave through evaporation. The arid climate causes over 50% of the lake’s water to evaporate every year. As water evaporates, the salts stay behind and become more concentrated.
The high salinity creates a harsh ecosystem where very few lifeforms can thrive But amazingly, some fish have evolved to call this salty oasis home
Fish Species Found in The Great Salt Lake
Here are the primary fish that inhabit Utah’s Great Salt Lake and how they’ve adapted to the salt:
Brine Shrimp
Brine shrimp are small crustaceans that swarm the lake by the trillions. Their eggs can remain dormant for years in the sediment. When water conditions are right, they hatch into tiny shrimp up to 1/2 inch long.
Brine shrimp have a high tolerance to salinity thanks to special cells that pump salts out of their bodies. They play a vital role as the base of the food chain.
Brine Flies
Brine flies flock the shores by the billions. They feed on algae and bacteria in the lake water. These insects secrete extra salt through their skin and exoskeleton.
Both brine shrimp and brine flies are a crucial food source for birds that migrate through the Great Salt Lake region.
Utah Chub
The Utah chub is a minnow species and one of the few fish able to tolerate the high salinity of the lake. They survive by staying in the fresher water of tributary inflows. Utah chub can grow over 16 inches long.
Redside Shiner
Another minnow species that inhabits the fresher incoming waters is the redside shiner. They only reach about 3 inches in length. Their silver bodies and red-tinged fins help them blend into the salty reddish waters.
Yellow Perch
A small population of yellow perch is found near the fresher waters flowing into Bear River Bay. They tend to be smaller in size compared to other habitats due to the stress of salts.
Rainbow Trout
Some rainbow trout live in the lake, but mainly in the spring when tributaries flush in fresh meltwater from the mountains. They quickly migrate back upstream as soon as salinity levels rise in the summer.
Bonneville Whitefish
The Bonneville whitefish has specially adapted gill structures to excrete excess salt. They tend to swim into fresher tributary inflows but venture into more brackish waters to hunt brine shrimp.
Bonneville Cutthroat Trout
Cutthroat trout subspecies are native to the region. The Bonneville cutthroat trout has evolved specialized gill tissues to pump out salt and urea waste. They prefer the fresher north arm and shoreline springs.
Common Carp
These large omnivorous fish tolerate brackish waters well. Carp patrol the nutrient-rich Farmington Bay mudflats feeding on brine shrimp, algae, and detritus. Thriving carp grow over 30 inches long here.
Channel Catfish
Channel “cats” inhabit the freshest sections of tributary deltas flowing into the Great Salt Lake. Their whiskers help them probe the muddy bottoms scavenging for food. They migrate further upriver when saline levels rise.
How Do Fish Survive the Salty Environment?
Thanks to evolutionary adaptations, a small number of fish species can withstand the hypersaline conditions of the Great Salt Lake that would kill most other freshwater fish:
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Osmoregulation – Specialized cells in gills and kidneys pump out excess salt and excrete concentrated urine.
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Salinity tolerance – Some species like Utah chub and carp tolerate brackish water better than strict freshwater fish.
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Migration – Many fish only inhabit the lake seasonally when tributary inflows lower salinity.
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Sheltered microhabitats – Fish stick to fresher springs along shorelines and river inflows.
Still, the extreme salinity stress means fish in the Great Salt Lake exhibit stunted growth and lower population numbers compared to other waters. And their numbers fluctuate widely based on precipitation and inflow levels.
In extra wet years, the lake’s salinity can briefly dip low enough for additional stray fish to survive there temporarily. But most cannot persist once salinity climbs back up.
Threats Facing the Great Salt Lake Ecosystem
While the highly adapted fish and shrimp species are equipped to handle the normal saline cycles, human activities threaten to disrupt the delicate balance of the lake.
Climate change exacerbates drought conditions that reduce freshwater inflows. Diversion of tributary waters for agriculture and urban use also lowers lake levels. Mining activities pollute waters with extra toxins.
In 2016, unusually low water levels caused salinity to spike far above normal, resulting in massive die-offs of brine shrimp. This disrupted the entire food web, causing millions of migratory birds to starve.
Conservation efforts aim to balance human water needs in the region with preserving adequate water flows into the lake. Time will tell if organisms can continue adapting to the lake’s increasingly harsh conditions.
The fact that any fish can survive in such a forbiddingly salty environment is a testament to nature’s incredible resilience. Utah’s Great Salt Lake ecosystem remains a beautiful yet fragile place worthy of our protection.
I’m grateful as an angler to have this unique saltwater oasis practically in my backyard here in Utah. Watching the spectacular sunsets over the lake never ceases to amaze me. I feel tremendously lucky to live so close to this natural wonder of the world.
