Populationion dynamics and ecology of beach wrack macroinvertebrates of the central California coast by Derrick R. Lavoie, Bull. Southern California Acad. Sci., 84(1): 1-22, 1985. The successional cycle of macroinvertebrates colonizing high intertidal beach wrack islands, decaying clumps of stranded kelp, were examined on a central California high energy beach. Samples from wrack algae and the underlying sand were taken at periodic intervals following island deposition. Mean density and number of different species fluctuated in regular and complementary patterns. Multivariate analysis distinguished early, mid, and late colonizing species. Dipterans and amphipods were initial colonizers succeeded largely by Coleoptera. Temporal changes in faunal populations are attributed to physical and biological factors degrading the wrack and reducing its potential as a resource. Beach wrack is a major nutrient source and substrate shelter for a majority of indigenous beach fauna.