Abstract : The report covers some aspects of work done on a study of a nearshore marine ecosystem (near Corona del Mar, California) since the report of July 1966. Additional data are provided on temperature-depth structures, and the ranges of salinity and dissolved oxygen found both at the sublittoral site and some 3,000 m offshore. Since the principal objective of this study is to provide an energy budget for a complex epifaunal assemblage, considerable attention has been given to autrotroph carbon assimilation, levels of soluble and particulate organic carbon in ambient waters, and to the growth rates of dominant species and the development of faunal assemblages on the rock-reef. (Author)