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San Francisco Bay salt flats © Jeffrey Lewis/Tandem Stills + MotionJoin Our GIFs Group
You might be wondering where the volcano is in today"s photo, but that"s not lava. These are salt flats in San Francisco Bay—many of these tidal marshes have been developed into evaporation ponds for the harvest of sea salt. If you happen to be in the air and flying over this part of the country, you"ll notice pools of not just bright orange but green, blue, and even magenta among the famous salt ponds. The vibrant colors are determined by brine shrimp, algae, and other microorganisms and their responses to different levels of salt. This orange results from a mid-level saline concentration and the presence of tiny brine shrimp in the water. Green indicates low levels of salt, while pink or red are signs of high salt content in an algae-rich pond.