Islands, rivers and man-made structures define several diverse microenvironments around the lake. The lake's microenvironments differ in many ways, including salinity (salt concentration), temperature and pollution levels. All of these factors determine which organisms survive and thrive in each location. The lake is also surrounded by wetlands and evaporation ponds, which have their own special characteristics and inhabitants.
One of the lake's most dominant features is the railroad causeway that runs from east to west across its middle. Built in 1959, the causeway blocks most water flow between the north and south arms of the lake. The three main rivers that supply fresh water to Great Salt Lake flow into the south arm, leaving the north arm much more saline. Only the most resilient microbes can live in the extreme salt conditions of north arm. These "extremophiles" give the water a distinct purplish to pinkish color. The south arm, with its lower salinity, supports a greener population of microbes.
Click around on the image to the right to explore seven of the lake's unique microenvironments: Gilbert Bay, Gunnison Bay, Farmington Bay, Bear River Bay, Ogden Bay, evaporation ponds, and wetlands.
Image courtesy NASA/Visible Earth