Katherine Bickford

I remember sand dollars being all over the beach when I was young, so I was a bit saddened to only see a few when I visited Rathrevor Provincial Park in the late summer. It was much the same at Miracle Beach,  and I did not see a single sand dollar at Kai Bay or Air Force Beach.

And then I walked a bit further along the beach and spotted a few dead sand dollars and a large amount of live sand dollars. A bit further along and there are a lot of sand dollars burrowed into the sand.

A lot of them…

Sand dollars have a rigid skeleton (known as a test) consisting of calcium carbonate plates arranged in radial pattern. In live sand dollars the test is covered by a skin of velvet-textured spines that are covered with very small hairs (cilia). Coordinated movements of the spines enable sand dollars to move across the seabed.

As with other echinoids, the endoskeleton of sand dollars have a radial symmetry with a  recognizable petal-like pattern consisting of five paired rows of pores.

Dead sand dollars are missing  the spines and are bleached white by sunlight. White sand dollars are dead, black sand dollars are alive and should be left where they are.