Number of species in thousands 



N M° 60° Jff' 



ff' 



jff° &ff' sff' S 



Zonality of distribution of certain biologic characteristics of the World 

 Ocean and levels of pollution of surface (euphotic) layers of sea \vater. 



a--Number of species of marine animals (after L. A. Zenkevitch) ; 



b, c--Biomass of benthos and plankton (after B. G. Bogorov and L. A. 



Zenkevitch); d--Cumulati ve global store of strontium-90 (Patin, 1965); 



e--Hypothetical curve of variation in levels of chemical pollution. 



Shaded areas show position of latitude band of elevated pollution. 



412 



