A Whole Lotta Nothing: I don’t know why I still store this stuff in my head

Finally an explanation of what the heck those colored sections of water around the SF Bay are – every time I fly in I wonder what it is and how I could find out…

I mentioned to Andy that when you drive around the Silicon Valley you see shallow areas of the San Francisco bay evaporating down to salts and he showed me this cool section of the bay. Now this is a bit different, the red and green colors appear to be due to algae blooms, and since they appear to be in contained areas, they’re purposefully there in order to help ‘scrub’ fertilizers from agricultural runoff heading into the bay. When runoff high in nitrogen or phosphorus hits these ponds, blooms form and the algae consume the nutrients, leaving cleaner water to pass back into the bay. Without this kind of cheap natural wastewater management, the blooms would happen in the main areas of the bay, choking out oxygen and often leading to fish kills and other problems. Red and green algae bloom in response to varying levels of nutrient load and temperature, so I’m not sure if the green algae blooms are in deeper pools or less nutrient rich ones, but that’s my guess as to why the big colored pools are there.


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