ABSTRACT
In this chapter I summarize and reconsider the material presented in the preceding chapters. References to specific publications will be given only where especially necessary; otherwise, the reader is advised to review the corresponding preceding chapters. The fundamental problems that are supposed to be solved here are as follows: Why do organisms concentrate on hard surfaces? What are the main mechanisms of this concentration? Why is it especially distinct in the coastal belt, where many man-made structures are situated? What are the limits of abundance and biomass of organisms on hard surfaces, and what are the factors that determine them? It should be noted that, in Chapter 1, the phrase “concentration of organisms” was proposed for designating the high abundance and biomass of organisms reached on hard substrates.
