There are three described species of brine flies at GSL, but researchers think that others exist.
Brine fly larval pupae casings have been known to reach numbers of 370 million/mile of shoreline in the summer. After mating, the female brine fly releases eggs into the lake, which hatch into larvae on the bottom of GSL.
These larvae are free-swimming and feed off algae and detritus until they are large and fat. They then find a good substrate (bioherms or anything floating) to attach to for their pupae life stage. Just like caterpillars, brine fly larvae form a "chrysalis", or casing, before they turn into adult flies! At Great Salt Lake, brine flies seem to prefer a bioherm substrate (see Bioherms section for more information).
As they emerge, flies surround themselves in an air bubble and float to the surface! Peak numbers have been reported in the billions, which isn't hard to believe when walking around the lake in the brine fly's summer peak!
When spring arrives, very little light reaches the lake bottom due to massive, un-grazed algal blooms (as a result of no shrimp or flies to eat it over the winter). The shrimp eat an enormous amount of algae with the warming temperatures, and thus allow light to penetrate the water far deeper. The clear water provides sunlight for blue-green algae growth on the bottom of the lake, the brine fly larvae preferred food source.
They start hatching in April/May and continue through October/November, usually peaking about 2 or 3 times. Brine fly larvae can ultimately consume up to 120,000 tons of algae and organic matter.