The rocky subtidal zone of temperate coasts is characterized by complex topography and equally heterogeneous distributions of marine algae and invertebrates. Long-term studies of subtidal rock walls (1987-1988) in Northern Massachusetts have produced and tested hypotheses concerning the long-term stability and short-term regulation of community structure on such substrata. Previous studies have focused on the interactions between species on rock walls, on the population biology of a few dominant species, and on the effects of water movement on individual, population, and community processes. The present this research will extend the long-term studies including a detailed analysis of separated population on nearby rock walls, and populations in contact with competing species. A mathematical model of the subtidal rock wall community will be developed. New information is needed on the role of larval dispersal and recruitment in this system, and its influence on the maintenance of patchiness of invertebrated populations. There are clearly three levels of larval dispersal (adjacent, local, regional) that affect population dynamics and thus community structure. These will be investigated using a combination of field studies, laboratory investigations, and modelling of large scale flow patterns and to incorporate the results into a realistic community model.
