5. The Trophic Structure of the Benthic Population 

 of the Shelves . (A. P. Kuznetsov, A. A. Neyman) 



In recent decades in Soviet oceanography, studies of the trophic 

 characteristics of the benthic population have been greatly developed. 

 Domestic expeditions have accumulated significant materials (over 3000 

 samples) of the bottom population of the shelves of the world ocean, 

 collected by a single methodology--by means of the "Okean" bottom 

 digger. This allows us to make a judgment concerning the peculiarities 

 of the composition and distribution of the benthos at depths from 10-20 

 m down to the upper levels of the slope (300-500 m) (Neyman, 1971). The 

 studies have encompassed all geomorphologic types of shelves in various 

 geographic zones. 



The detailed studies of Ye. P. Turpayeva (1953, 1954) allowed her 

 to work out a classification of marine benthic invertebrates on the 

 basis of the source and method of capture of food. Studying the bottom 

 population of the Barents Sea, Ye. P. Turpayeva distinguished the 

 following trophic groupings: "swallowing"--inhabiting the surface 

 layers of bottom deposits and swallowing the bottom whole; "gathering"-- 

 gathering detritus from the surface of the bottom; "A filterers"-- 

 feeding on matter suspended in the thin layer of water along the bottom; 

 "B filterers" (active filter feeders)--feeding on layers of water 

 located higher above the floor; "waiters"--receiving their food from the 

 same layer as B filterers, but passively. 



The nonpredaceous benthic invertebrates feed on the organic matter 

 suspended in the water or in bottom deposits; therefore, the quantity of 

 food available to them in any given section of the bottom is directly 

 dependent on the productivity of the overlying photic layer. The 

 abundance of food for predaceous animals (benthophagous fish, large 

 crustaceans, etc.) depends on the distribution of nonpredatory 

 invertebrates. Therefore, in studying the connection of the 

 distribution of benthos with oceanographic characteristics (biotic and 

 abiotic), we must first turn our attention to the peculiarities of the 

 distribution of nonpredaceous benthic invertebrates, the first consumer 

 link in the detrital food chain. 



Ye. P. Turpayeva has shown that the distribution of biocenoses with 

 predominance of swallowing and gathering animals, in terms of weight, is 

 positively correlated with the content of fine fractions of bottom 

 sediments, biocenoses with predominance of "A filterers" are correlated 

 with the content of middle-sized fractions, biocenoses with predominance 

 of "B filterers" and "waiters" are correlated with the larger 

 fractions. Further study of the groupings has involved their spatial 

 distribution. A. I. Savilov (1961) traced the regularities of their 

 placement in the Sea of Okhotsk. In separating ecologic groupings, he 

 utilized information on the sources of food, methods of its capture, 



204 



