Sea Urchin - More than Just a Pretty Shell

Sea urchin shells are often seen as little flashes of colour in the mass of broken shells and pebbles on the shoreline. However, these marine creatures have gone on a long journey to get to this stage.

Sea urchins (Echinus esculentus) live around the shores of the UK down to depths of 1000metres. They can be as small as an apple or as large as a football with a thin brittle shell which is covered in small spines and tentacles that waft in the current. There is enjoyment seeing these prickly creatures grazing on seaweed and algae at 30metres as you drift by on the current. As with all sea urchins their bodies and shells are weirdly divided into five sections - why five? Clearly visible underwater the sections become even clearer when just the shell is found.

As with any creature their lives will end. Many will be victims of deep sea trawling and habitat destruction and the species is near threatened. Some will be washed ashore in storms or predated by otters and seals. The fragile shell and spines will remain even after the squishy insides have been eaten or washed away.

Slowly over time the action of the waves will remove the spines from the shell, eventually leaving just the familiar inner shell. To find a whole shell is a special treat on any beach adventure and a treasure from any adventure.