<P> Because of the Great Salt Lake's high salinity, it has few fish, but they do occur in Bear River Bay and Farmington Bay when spring runoff brings fresh water into the lake . A few aquatic animals live in the lake's main basin, including centimeter - long brine shrimp (Artemia franciscana). Their tiny, hard - walled eggs or cysts (diameter about 200 micrometers) are harvested in quantity during the fall and early winter . They are fed to prawns in Asia, sold as novelty "Sea - Monkeys," sold either live or dehydrated in pet stores as a fish food, and used in testing of toxins, drugs, and other chemicals . There are also two species of brine fly as well as protozoa, rotifers, bacteria and algae . </P> <P> Salinity differences between the sections of the lake separated by the railroad causeway result in significantly different biota . A phytoplankton community dominated by green algae or cyanobacteria (blue - green algae) tint the water south of the causeway a greenish color . North of the causeway, the lake is dominated by Dunaliella salina, a species of algae which releases beta - carotene, and the bacteria - like haloarchaea, which together give the water an unusual reddish or purplish color, and the bacteria converts non-toxic mercury into toxic methyl mercury, which then flows into the Southern portion of the lake in a heavy brine layer through the causeway . </P> <P> Although brine shrimp can be found in the arm of the lake north of the causeway, studies conducted by the Utah Division of Wildlife Resources indicate that these are likely transient . Populations of brine shrimp are mostly restricted to the lake's south arm . </P> <P> In the two bays that receive most of the lake's fresh water inflows, Bear River Bay and Farmington Bay, the diversity of organisms is much higher . Salinities in these bays can approach that of fresh water when the spring snow melt occurs, and this allows a variety of bacteria, algae and invertebrates to proliferate in the nutrient - rich water . The abundance of invertebrates such as gnat larvae (chironomids) and back swimmers (Trichocorixa) are fed upon extensively by the huge shorebird and waterfowl populations that utilize the lake . Fish in these bays are fed upon by diving terns and pelicans . </P>

Where does the salt in the great salt lake come from