CHARACTERISTICS OF PELAGIC AND BOTTOM LIFE 331 



In 1959 aboard the Lomonosov, a series of samples was obtained 

 with a bottom sampler in the Atlantic along the 30th meridian 

 (from Greenland to 20°S). A preliminary examination of this 

 material (Kusnetzov, 1960) shows that the quantitative distribu- 

 tion of both the pelagic and bottom fauna in the Atlantic is similar to 

 that in the Pacific. Localities having a biomass of 10 mg/m^ are 

 especially notable. In the abyss off Brazil, however, the biomass 

 is practically nil. Now with the data on the quantitative distribu- 

 tion of the bottom fauna in all oceans, it is possible to estimate 

 its total biomass more precisely as about ten tons. 



The regularity of the quantitative distribution of the oceanic 

 plankton and benthos is somewhat different (Fig. 4). I have 



Fig. 4. Schematic representation of varied quantitative plankton and benthos 

 distribution in the total ocean. 



attempted to show this by a simple diagram of the quantitative 

 distribution of the bottom fauna, chiefly offshore, but the zonation 

 determining the distribution of planktonic organisms in the surface 

 layers is largely latitudinal. Unfortunately, our data for the 

 quantitative distribution (biomass) of oceanic plankton is insuffi- 

 cient for mapping all the oceans but the distribution of the biomass 

 at several levels in the world oceans can now be demonstrated.* 

 Fluctuations in the planktonic biomass are markedly less — they 

 range from a few grams in coastal areas and decrease to a fraction 

 of a milligram (0.17 mg/m-) offshore in the ocean depths or 

 fluctuations of ten thousand times. This shows that food for 



* The specimens collected by the Lomonosov in the Atlantic Ocean have not yet been 

 charted. 



