These edited proceedings, first published in 1985, provide a thematic review of four important areas of marine biology. The theme of the first part of the volume is production at boundary systems and in particular it deals with rates of production and related processes at boundary systems, including shelf breaks, thermoclines and the fronts between stratified and mixed waters and the contribution of the production of such systems to the overall productivity of a region. The second part look sat the dynamics of deep-sea life: new techniques of and results from direct observation, in situ experimentation and sampling, especially those concerning rates and processes in the deep sea. The third part examines concepts of community organisation in the benthos: theoretical and empirical studies that synthesise the structural and functional properties of benthic communities. The final section on adaptive relevance of variability in biochemical and physiological processes, with particular emphasis on relationships between population genetics and physiological and biochemical ecology.