1. Common heavy metals such as Selenium and Mercury are released into the atmosphere and water table by natural and anthropogenic activities.

Find out about local mercury sources

2. The Great Salt Lake was once thought to be an effective disposal system where toxins accumulated in the deep layer of the lake. Recent studies indicate that the chemistry of the lake may actually speed the inclusion of heavy metals in compounds that can be absorbed by living organisms. The abundant phytoplankton (free floating algae and diatoms) in the lake absorb these heavy metal compounds.

Phytoplankton under the microscope

3. After hatching, brine shrimp feed intensively on the phytoplankton blooms. Heavy metal compounds cannot be broken down by brine shrimp metabolism, and are instead stored in fatty tissues.

As the brine shrimp graze on more phytoplankton, the concentration of heavy metals in their fatty tissues becomes higher and higher.

Brine shrimp life cycle and industry

4. Birds living in and around Great Salt Lake feed on the abundant brine shrimp. Certain types of insects (Corixid beetles) also feed on brine shrimp, and are, in turn, prey for birds. By eating huge amounts of brine shrimp, both birds and insects further concentrate heavy metal compound in their tissues, bringing concentrations in their cells to toxic levels.

Birds of Great Salt Lake

5. Volatization of Mercury into the air

or

Migration:  Great Salt Lake hosts millions birds every year during migration, and is an essential habitat and food source for these birds. As the birds continue on their migration route, they carry with them the heavy metals they have ingested while resting at the lake.

Migration patterns and Wetlands slide show