fi:'!} 



Jfff 



S 4( 



J7 o <r 



^ ^M 



IF 



JY JT 



IT 



Fig. 14. Changes in vertical structure of population of interzonal 

 species during the annual cycle. Roman numerals show position of median 

 of hemi populations of individual copepodite stages. 1, Winter; 

 2, Beginning of spring migration; 3, End of migration, spawning; 

 4, Development of new generation; and 5, Beginning of fall sinking 

 (Voronina, 1975). 



Fig. 15. Seasonal changes in vertical 

 distribution of interzonal species 

 population (Voronina, 1972). 



of a certain age, and maximum biomass and the downward migration occur 

 earlier in the northern latitudes and later further south (Voronina, 1969, 

 1974; Voronina, 1970). Deviations from this sequence are related to 

 hydrologic peculiarities which define the deviations in the time of 

 beginning of intensive phytoplankton production (Voronina, 1975). The 



91 



