Exploring the planet’s most saline habitats reveals a surprising fact: the Dead Sea is not the saltiest body of water on Earth. Scientists rank brine pools and lakes by their salt concentration, measured as a percentage of dissolved solids. While the average ocean contains about 3.5 % salt, some isolated basins retain up to 44 %.
Below is a concise rundown of the world’s most hypersaline bodies of water, each a unique laboratory for studying extremophiles and planetary analogues.
Located in Antarctica’s McMurdo Dry Valleys, Don Juan Pond is the saltiest liquid on Earth. Its shallow basin can reach 44 % salinity, a concentration high enough to keep water liquid even at –50 °C. The brine is dominated by calcium chloride, which inhibits ice formation. Researchers study this pond because its extreme conditions mirror the chemistry of Mars’s polar regions.
In Ethiopia’s Danakil Depression, Gaet’ale Pond reaches 43.3 % salinity. Unlike its Antarctic counterpart, this thermal pond experiences temperatures of 50–55 °C (122–131 °F). Its chemistry is rich in calcium and magnesium chlorides, offering insights into hot, salty environments on Earth and beyond.
Lake Vanda in Antarctica’s Wright Valley hosts deep layers of brine approaching 35 % salinity. The lake remains partly ice‑covered year‑round, yet the saline water beneath creates a layered system where highly saline brine sits under fresher water.
Lake Assal in Djibouti’s Rift Valley boasts about 35 % salinity. Its shoreline lies far below sea level, and intense evaporation concentrates the remaining water. The surrounding landscape is a stark white tableau of mineral deposits.
Between Jordan and Israel, the Dead Sea’s 34 % salinity makes it one of the world’s most famous hypersaline lakes. Its density allows effortless floating, and its mineral‑rich mud has attracted health‑tourism and scientific research for decades.
In the western United States, the Great Salt Lake’s salinity fluctuates dramatically. Wet years can bring salt levels down to 5 %, while dry periods push concentrations to 27 %. Recent water‑level declines have increased salinity in some areas.
Laguna Cejar, a sinkhole lake in Chile’s Atacama Desert, shares the Dead Sea’s buoyancy. Its high salt content is the result of limited freshwater inflow and high evaporation rates.
Although not a lake, the Red Sea’s average salinity of 4 % exceeds that of most oceans. Its hot temperatures, low rainfall, and minimal river input keep the salt concentration elevated, supporting a rich marine ecosystem.
Beyond Don Juan Pond, the McMurdo Dry Valleys host numerous small hypersaline ponds where meltwater mixes with highly saline soil. With no outlets, evaporation concentrates the brine, creating habitats for specialized halophiles and extremophiles.
These lakes typically sit in closed basins with no outflow. Rain, snow, and small streams introduce dissolved minerals, while evaporation removes water but leaves salts behind. Over time, this process builds up extraordinary salinity, supporting only specialized life forms.
Studying these extreme environments helps scientists understand how life can persist under conditions similar to those on Mars and other planetary bodies.
We created this article in conjunction with AI technology and subsequently fact‑checked and edited it by a HowStuffWorks editor.
