Haematococcus Red

Haematococcus pluvialis is a freshwater green microalgae that is extremely common in many areas of the world. You may have observed it as the pink stuff in your birdbath!

Haematococcus is usually deep green in color, but when stressed, becomes extremely high in a caroteniod called astaxanthin. Astaxanthin is a powerful antioxidant commonly used in aquaculture, cosmetics, and occasionally as nutritional supplements. This caroteniod is deep red in color, giving the algae its pinkish appearance.

Haematococcus Materials Test - Haematococcus pigment on paper 2021

Grow & Observe

Haematococcus grows in a wide variety of freshwater environments but is most recognizable by the pink film it creates when reacting to stress conditions. The haematococcus in my algae farm is growing under ideal conditions, so it is a deeper green than wild colonies. Observed under the microscope, the astaxanthin is readily observable. I really think haematococcus is quite beautiful!

Haematococcus biofilm observed in a drained fountain at Cal Anderson Park in Seattle, WA

Color Experiments

Haematococcus-derived astaxanthin is easy to find and purchase. Using a variety of sources, I mixed a watercolor base with the powder, resulting in a rather grainy paint. This paint would need to be muddled in the future to be satisfactory to work with, as it clumped and had issues flowing.

The resulting paint had a deep earthy red similar to iron oxide pigments. Sadly, because this is a carotenoid, the painting is discoloring and fading over time. This result has pushed me to explore preservatives and stabilizing techniques.

Materials test in progress with source pigment powder