Tidepool living has to be tough. Each day cycles through wet, cold and sheltered to dry, warm and exposed, then repeats. Last week I spent some time photographing and exploring tidepools during morning low tides. Amazing what’s there, and the closer you look, the more there is to see. In this photo the obvious species are sandcastle worm tubes surrounding mussels dotted with barnacles. I’m sure you’d find more if you looked closely — maybe algae, limpets, tunicates or hidden crabs. But that’s for another time.
For this post, I’m focusing on the shots I got of sea anemones in tidepools that still contained water (without water they close up or droop and wait for the tide to wash back in). I found three species during my morning ventures.
The giant green anemone (Anthopleura xanthogrammica) is a wow green and stands out in the sand or a shallow pool. This species grows to 8 inches (20 cm) across. Sea anemones look like flowers but are animals closely related to jellies, complete with tentacles and stinging cells for capturing food. (These stinging cells are typically too light duty to harm people.)
The sunburst anemone (Anthopleura sola) is not as brightly colored as the giant green, but is distinguished by lovely lines on a pale blue-green oral disc (the flat mouth side). This species grows to 6 inches (15 cm) across. Sea anemones keep their distance —they have special stinging clubs and will do battle with anemone neighbors to keep them away.
The third species in our area is smaller and more cozy than the other two. The aggregating anemone (Anthopleura elegantissima) grows to 2.5 inches (6 cm) and is found in groups (members of the group are clones). Clonal communities keep separate from one another — you can spot a demilitarized zone between them. At low tide aggregating anemones create a squishy carpet. In several places I had to be very careful not to step on them as I moved between the rocks.
If you get a chance, visit a tidepool at low tide to discover its wonders, but walk carefully and don’t disturb the residents. Tidepool life is vulnerable at low tide, especially to foot traffic and exposure. If you’re interested in more about Monterey Bay sea anemones, look at the Monterey Bay National Marine Sanctuary SIMoN Species Database or Hopkins’ Seanet Common Intertidal Organisms of Monterey Bay website.