In the occasion that you’ve landed a window seat on an incoming flight into San Francisco, you probably witnessed this visual treat — mind-boggling patches of bright colors and intricate fractal-like patterns on the land below.

No, that isn’t a hallucinated mirage from one too many airplane cocktails. It’s the Cargill Salt Ponds, and they are one of my favorite things to experience from up above.

176838905_1d19801271_bTodd Lappin via Flickr

Located all over the South Bay, the ponds range in color from blue-green to a deep magenta due to the three microorganisms that thrive in varying salinity levels: Synechococcus, Halobacteria, and Dunaliella.

Algae and Dunaliella flourish in low salinity levels, resulting in green hues; with increasing salinity levels, Dunaliella continues to dominate other microorganisms and the colors shift to a bright mustard yellow.

At this point in the evaporation process, the population of the tiny brine shrimp skyrockets and darkens the water. It’s now Halobacteria’s time to shine, taking over and turning all the protoplasm of Dunaliella into a deep red.

4096329287_d102930564_bDoc Searls via Flickr
3021784440_2c3018bf8c_bDoc Searls via Flickr

This fascinating natural process is tied to a lucrative industry. First entering the salt business in 1954, Cargill didn’t operate in California until they acquired Leslie Salt in 1978; here, the Cargill sea salt works utilize “the ancient technique of harvesting salt from bay water with the help of the sun and wind.”

Refining over 500,000 tons per year, salt-making is a five-year process — from the moment the water is drawn from the Bay to the scraping of the crystallizer beds and refinement.

2819452713_58f31967e2_bDoug via Flickr

According to Atlas Obscura, the salt industry has played a prominent role in San Francisco since 1854. Due to our clay soils and Mediterranean climate, the San Francisco Bay Area is ideal for sea salt production — it also happens to be one of only two sea salt works in the entire United States.

3474886183_102f056333_bDoc Searls via Flickr
4096332979_7f93ddf4a4_bDoc Searls via Flickr

You can even see the colorful swatches from space — Astronaut Chris Hadfield shared the following photo of how the Bay Area looks from the International Space Station.

3c64936f-07ba-4072-abc0-069a76150f76-2060x1236Chris Hadfield/NASA

On my most recent flight, I was treated to the whimsical view below.

Processed with VSCOcam with c1 preset© Jenna Homen

Cargill Salt Works is recognized for their work on environmental preservation — they footed the bill for the largest wetland restoration project on the West Coast. The purpose of the project is to slowly introduce bay water and integrate wildlife to the ponds, meaning that this optical experience might not be around forever.

If you are curious about seeing up the salt ponds up close and personal before it’s too late, you can visit the Don Edwards San Francisco Bay National Wildlife Refuge.

Have you had a chance to catch a glimpse of the ponds?

[Featured Image: Doc Searls via Flickr]

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