The Great Salt Lake is a vast natural landmark. It is the largest saltwater lake in the Western Hemisphere and ranks among the world’s largest terminal lakes.
The Great Salt Lake’s Unique Environment
The Great Salt Lake is a terminal, or endorheic, lake, meaning it has no outflowing rivers or streams. Rivers such as the Bear, Weber, and Jordan feed into it, carrying dissolved minerals and salts. Since water only leaves the lake through evaporation, these minerals accumulate, leading to exceptionally high salinity levels.
The lake’s salinity fluctuates considerably depending on water levels, precipitation, and evaporation rates. Salinity can range from approximately 5% in fresher areas like Farmington Bay to as high as 27% or 28% in the North Arm, making it several times saltier than the ocean’s average of 3.5%. This extreme salt concentration creates a challenging environment for most aquatic organisms. High salinity causes osmotic stress, where water moves out of an organism’s body, leading to dehydration and potential organ damage. The main body of the Great Salt Lake is inhospitable to most aquatic species, including fish.
Life That Thrives in the Main Lake
The Great Salt Lake supports a specialized and thriving ecosystem. Brine shrimp are the most prominent inhabitants, exhibiting remarkable adaptations to this extreme environment. These small crustaceans possess sophisticated osmoregulation systems that actively pump excess salt out of their bodies. They also have specialized hemoglobin, enabling efficient oxygen uptake even in low-oxygen, high-salinity waters.
Brine shrimp are also known for producing resilient, dormant cysts, which are eggs encased in a protective shell that can survive desiccation and extreme temperatures, hatching when conditions become favorable. These shrimp serve as a food source for millions of migratory birds that visit the lake annually and are commercially harvested for aquaculture worldwide. Alongside brine shrimp, brine flies are abundant. These non-biting flies are abundant along the lake’s shores, with their larvae developing underwater, feeding on algae and organic matter. Both brine shrimp and brine flies rely on the lake’s abundant algae, which form the base of the food chain and produce oxygen essential for these invertebrates.
Fish in Connected Waters
While the main expanse of the Great Salt Lake is too salty for fish, freshwater tributaries, rivers, and associated wetlands provide suitable habitats for diverse fish populations. The Bear, Weber, and Jordan Rivers flow into the lake, creating areas of lower salinity, especially near their deltas and in connected bays like Farmington Bay. These less saline environments, along with spring-fed areas like Locomotive Springs, support various fish species.
For instance, the Bear River is home to fish such as rainbow trout, northern pike, brook trout, channel catfish, walleye, carp, and suckers. The Jordan River, flowing from Utah Lake, supports common carp, Utah sucker, channel catfish, white bass, and rainbow trout. The Bonneville cutthroat trout, native to the region, is found in the tributaries feeding the Great Salt Lake. The least chub can also be found in some freshwater springs and wetlands connected to the lake. However, if these fish venture into the main Great Salt Lake, they cannot survive.