The Jekyll Island Authority had a photo contest a few years back. Being an “image junkie,” I jumped at the chance to be a judge. The director, Nancy Kring-Rowan, pulled together a massive bunch of photos for the day. She grouped them into categories. It was a marvelous day of looking at a lot of pictures of Jekyll.
We went through the first batch fast. It narrowed our search down to images that stood out from the crowd. One of my favorite photos was a live sand dollar moving into the sand. Not many people know that white sand dollars were once alive, and are essential to the beach ecosystem. Living on the edge of two worlds, land and sea, I am continually learning and getting a clearer picture of how every living thing has a significant role to play.
On a day in late January, the tide was low, so I was walking along Driftwood Beach. There were a bunch of live sand dollars stranded. My friend and I gathered them up and put them in some puddles. When they got to the wet sand, they quickly buried themselves. They were gone in a heartbeat.
Yes, we love finding them all bleached white on the beach. They decorate our homes.
Yet, they are more than just decoration. They are an essential part of the beach. Watching them bury themselves under the sand made me ask some questions. Why were they there? What role did they play on the beach?
Sand dollars are animals and are actually called Keyhole Urchins. They are related to starfish, but instead of five arms, their hard, round bodies have cilia-like little tube legs. These legs move them around in the sand and shallow water, eating algae, and cleaning up plants’ detritus (or dead leaves). Once I learned that, I thought — “wow, they are the Roomba of the beach.” They are shuffling along, clearing up the nasty stuff that would clog our beaches. All the while, they are keeping the sand loose.
Keyhole Urchins have a complex life cycle. They go through several stages to get to what we know as a sand dollar. They start life as swimming larvae. These larvae are covered with cilia to help steer them through the water.
As it grows, it eats sand and stores it in the gut to weigh itself down as it
develops into an adult. They are not alone as they shift through the sand. These urchins have a hitchhiker clinging to them. The Pea Crab gets its name because it is tiny. It hangs out close to the urchin’s mouth and steals part of food it digs up. These urchins are feeding a family.
Too many times, I have heard about people gathering up the green fuzzy live sand dollar to boil off the cilia and paint them as things to sell. Please don’t — put them back. We need the Roomba of the beach to help keep our beaches clean.