Honeycomb worm (Sabellaria alveolata) reefs

Honeycomb worm reef © Jen Liles

Honeycomb worms build tubes from sand and shell fragments.  They are found on the lower part of rocky seashores but they also need a sand supply for tube-building.  They are, therefore, found on exposed shores where there is sufficient water movement to bring a sand supply from nearby.  They need hard rock to build on, and sand to build with – their requirements are very specific.  These worms are highly gregarious and live close together, their tubes forming sheets or reefs in a honeycomb pattern. They may form large reefs up to several metres across and a metre deep.

These living reefs provide a habitat for other shore-dwelling animals and seaweeds, such as anemones, snails, shore crabs and seaweeds such as sea lettuce.

Honeycomb worm reefs are vulnerable to storm damage and extreme cold weather, after which they may die back for several years.  Other threats include being buried by sand as a result of sea defence work and beach replenishment, although they can survive burial for days or even weeks.  Trampling and pollution can also affect the reefs.

For the official habitat definition please see the documents listed below.


European distribution

In Britain, honeycomb worm reefs are most abundant on the south and west coasts with isolated records from the south-east and east coasts. The northern limit is the Outer Hebrides. It is also found on south, west and north coasts of Ireland.


Conservation status/need

Honeycomb worm reef fact

This is a UK BAP Priority Habitat (BAP habitats are now Habitats of Principal Importance/Priority Habitats).


Official definition

UK Biodiversity Action Plan; Priority Habitat Descriptions. BRIG (ed. Ant Maddock) 2008 (updated December 2011) 


Further information

UK Marine Special Areas of Conservation - Sabellaria alveolata

Marine Life Information Network - Honeycomb worm Sabellaria alveolata

JNCC biotope classification - Littoral Sabellaria alveolata honeycomb worm reefs

JNCC - UK BAP Priority Species and Habitats

JNCC EUNIS habitat correlations table