Interactions between foraminifera and macrofauna have been little studied, especially on rocky coasts. This paper examines (a) the foraminiferal tests captured from suspension by the polychaete Sabellaria alveolata in an intertidal area on a rocky shore, and (b) the foraminifera living on those S. alveolata colonies. The rocky coast at Ceinewydd (Ballantine Exposure Scale 6) supports patchy colonies of S. alveolata similar to 1 cm thick. We collected similar to 10 cm(2) areas to form three Sample Sets of four replicates each at low tide. Two Sample Sets came from a 1 m(2) lower shore rock-pool, Sample Set 1 being taken above water and Set 2 below water. Sample Set 3 was collected from a middle shore cobble. Four replicates were taken for each Set. The replicates were disaggregated, soaked in a rose Bengal solution and dried. The residues (106-2000 mu m, 7-9 g aliquots) were picked clean of foraminifera. The total (live dead) assemblage comprised Ammonia batava (53.6%), with lesser Asterigerinata mantilla (11.1%), Bulimina elongata (7.5%) and Elphidium selseyense (5.6%). There were no statistically significant (p < .05) differences between the Sample Sets for: (a) the number of foraminifera per gram of sediment, (b) the mean proportions of either A. batava, A. mamilla or B. elongata, (c) mean species richness and (d) mean Shannon Function. However, the total assemblages' mean proportions as E. selseyense differed significantly between the Sample Sets. A small, zoned live assemblage was recovered for the sabellariid samples, with Elphidium macellum (Station 1) and E. selseyense (Station 2). We conclude that the worm-tubes retain pockets of seawater at low tide in which foraminifera can live.
