A survey at Hamble Spit showed that C. tentaculata was less abundant near high water mark than farther down the shore. The influence of various environmental factors on the worms' distribution was investigated, and it was concluded that temperature, salinity, oxygen content, and water content were of minor importance. Both the particle size of the mud and its carbon content showed some correlation with the abundance of the worm. However, periodic strong wave action seemed to have the most influence on the distribution of the worm over the mudflat.