Diatoms

Description: Diatoms are a unicellular algae and one of the largest groups of organisms on earth. They may live individually or in colonies. The colonies often form shapes, attaching to each other to form chains, zig zags, or star shapes. Diatoms are the most frequently seen phytoplankton at Haystack Rock, mostly because they form the large blooms of sea foam that line and color the beach.

Sea foam is most often formed by diatoms! When large algal blooms die and start to decay offshore, strong winds and waves churn up this organic matter forming foam. While most sea foam is harmless, specific effects may depend on the specific species causing the foam. These differences and what else is in the water can also change the appearance of the foam - from how thick it is, the color of it, and how long it sticks around.

Habitat: Diatoms tend to be very picky about the waters they live in. They have specific ranges of pH, salinity, nutrient concentrations, etc. that they thrive in. This helps tell scientists a lot about the quality of water in certain areas.

Tide Pool Tidbits:

• New species of diatoms are discovered every year - scientists estimate there could be 2 million different diatom species!

• Between 20-30% of the oxygen we breathe is produced by diatoms.

• The cell walls are made of silica, giving them a glass house. This means sea foam is also tiny bits of glass which could be harmful if consumed - don’t let your dogs munch on the foam!

References: Monterey Bay Aquarium, Diatoms of North America, NOAA