Along the Colourful Coast when the tide is out and the lower shore is exposed you can often find strange looking honeycomb like structures forming hummocks or sheets across the rocks and sand.
These fragile structures are the home of the aptly named honeycomb worm (or Sabellaria alveolata if you want to get technical). The reefs are formed from the closely packed sandy tubes constructed by these colonial worms to live in. The reef structures resemble honeycomb (hence the name honeycomb worm) and can extend for tens of metres across and up to a metre deep, constructed of thousands or even millions of individual tubes. The worms are very specific in their requirements for forming reefs – as well as needing a hard substrate to attach to, they also need a supply of sand for tube-building so they are found on shores where there is sufficient water movement to bring a sand supply from nearby. Their tubes are made by gluing sand and shell fragments together with mucus. The worms head protrudes from the tubes to feed when the tide covers the reefs and then retreat into the protection of the tube as the tide goes out. The reefs also provide habitats for a wide range of other animals including anemones, snails, shore crabs and seaweeds.
Honeycomb worm reefs are just one of the unique aspects of the Colourful Coastline, and one of the reasons why the area was designated as a Marine Conservation Zone, or MCZ. The Cumbria Coast MCZ stretches for approximately 27 km along the coast of Cumbria, extending from south of Whitehaven, around the cliffs at St Bees Head, to the mouth of the Ravenglass Estuary. More information about the MCZ can be found on the Natural England website.