thehalsteadfamily's picture

Mysterious brittle sand structure on the beach

Observed: 2nd June 2011 By: thehalsteadfamily
Brittle sand structure

Found on Criccieth beach North Wales, these large brittle structures made of sand were both on the sand itself and attached to rocks. They almost reminded me of a wasps nest! Mussels were attached to the same areas - wonder if the two are related? They were obviously strong enough to withstand the waves but were very brittle and could be crumbled between the fingers. Unlike anything I've ever seen and a complete mystery to me!

Species interactions

No interactions present.


jonmortin's picture

Sabellaria alveolata reefs

Sabellaria alveolata reefs are a UKBAP Priority Habitat and are often associated with a diverse community of other organisms. More info at and click on link to Sabellaria alveolata reefs.

Mike Kendall's picture

Sabellaria alveolata

This is a Sabellaria reef that has been inundated by sand and so looks a little atypical. Such reefs are a common feature in West Wales.

Mussel larvae are sometimes not very particular on where they settle and the prospects of a mussel growing to adult size having settled on a brittle surface close to the worm tube opening is pretty slim. On the other hand, if settlement were to take place on the body of the reef and the anchoring byssus was spread across the body of the tubes of a number of individual worms then survival prospects might be rather better.

Mike Kendall

nick_the_grief's picture

Haven't seen this for years

Haven't seen this for years ... still, I am about as far away from the sea as you can get !

North Warwickshire