The ‘ross worm’, Sabellaria spinulosa Leuckart 1849, is a sedentary, epifaunal polychaete that builds rigid tubes from sand or shell fragments. It is a suspension feeder that is generally found individually but can be gregarious in favourable conditions, and colonies consisting of fused sand-tubes may form thin crusts or extensive reefs.
To date, in the UK, well-developed and stable S. spinulosa reefs are only known within the Wash and its surrounding waters. Thus within the Wash and north Norfolk Coast cSAC, biogenic sand reefs built by S. spinulosa are an interest feature which has recently been upgraded from being a sub-feature of the Large Shallow Inlet and Bay to a ‘reef’ interest feature in its own right. It is important, therefore, to test many of the assumptions about the importance of this species to the overall pattern of species diversity and richness in the Wash, and also to clarify the anecdotal evidence which has suggested a decline in the abundance and distribution of this species in the area.