Disturbances in ecological systems can cause new resources to become available and can free the resources held by strongly competitive species. In intertidal boulder fields, wave-action causes disturbance by overturning boulders and freeing space for re-colonisation. In this study, mensurative experiments showed that boulder disturbance may also cause new biogenic-habitat resources to become av...

Biogeomorphological processes are an important component in the geomorphic evolution of rocky coasts. Sessile organisms, including those which form dense biological covers, enhance and/or retard weathering and erosion. The common blue mussel (Mytilus edulis) is found on shores many parts world, typically forming extensive beds several centimetres thick. Yet, unlike other canopy marine organisms...

Regional oceanographic processes are emerging as strong influences on growth and recruitment of intertidal species, with important consequences for populations. Yet local conditions such as wave exposure are also important. To disentangle these effects for the intertidal barnacle Semibalanus balanoides, we surveyed 259 sites around Scotland in July and August over 6 yr (from 2001 to 2006). Scal...

Theoretical models predict that the relative importance of competition and facilitation vary inversely along gradients of abiotic stress, with facilitation dominating under harsh conditions (the so called ‘‘stress-gradient hypothesis’’). To date, very few studies have tested this hypothesis in the framework of succession. Moreover, the generality of the hypothesis is currently under debate and ...

Eutrophication can profoundly change rocky shore communities. These changes often cause the replacement of perennial, canopy-forming algae such as Fucus spp. with annual, bloom-forming algae such as Enteromorpha spp. Grazing, however, can counteract eutrophication by eliminating the annual algae’s susceptible recruits. We examine these generalizations across large scales. We use replicated ‘‘bi...

A wave-exposed sea stack and a protected boulder beach at Cayucos Point, California, were compared in terms of their intertidal biota on 17-18 February 1973. The major differences between the two sites appear to be due largely to differences in the shearing forces of waves and habitat structure. The mosaic of crevices, rivulets, and angled substrates in conjunction with a broad gradual slope an...