Factors affecting the distribution of the epiphytic fauna ofCorallina officinalls(L.) on an exposed rocky shore

Abstract

The distribution of the red alga Corallina officinalis and the fauna associated with it have been investigated in permanent rock pools at Filey Brigg, North Yorkshire. The pools are all shallow and of an unusual shape, possessing a vertical rock step at the rear (southern) side, away from the direction of waves. All the organisms investigated showed evidence of being at least partly regulated in their density by physical variables, including depth of pool and frond density of C. officinalis. The most important single variable, however, was proximity to the rock step, or ‘back wall’, which in the case of the polychaete Spirorbis corallinae accounted for up to 68% of the observed variation in abundance.