Salt evaporation ponds in San Francisco Bay, California

© Jason Hawkes/REX/Shutterstock

Salt evaporation ponds in San Francisco Bay, California

Along the southern shores of San Francisco Bay, acres of shallow water are isolated from the rest of the bay. The water in these ponds evaporates and the salt is harvested and processed for sale across the western United States. The evaporation ponds show different colors because of the microorganisms that thrive in the high-salinity water. Only some salt-tolerant algae live in the ponds with the highest salt concentration.