The third summer marks a transitory period in the existence of young herring. By the end 

 of the summer, they reach 15-18 cm. in length. Fat reserves accumulate in tissues and body 

 cavities, gonads begin developing. With the advent of the cooler autumn season, the area of dis- 

 persal of three-year-old fish decreases in size as the fish concentrate in the regions affected by 

 warm waters of the North Cape current. The movement of herring takes on a directed character, 

 in view of which we regard this particular moment as the beginning of their return migration. 



Our observations (15) showed that the character of young herring growth under diverse 

 conditions over its vast range in the Barents Sea varies greatly and determines the behavior of 

 herring to a considerable degree . 



The highest rate of growth was observed in herring from the western zone of the sea; the 

 rate decreases as we proceed towards east and north. The herring population of the White Sea 

 shows the lowest growth rate . The sizes of herring specimens hatched during the current year in 

 different regions were as follows. The mean length of 1 -year-old fish of the generation hatched in 

 1932 off the Murman coast fluctuated in different samples between 7.8 and 10.5 cm., whereas in 

 the White Sea it was 6.2 cm. The length of herring hatched during the year of the generation 

 hatched in 1933 in the coastal zone of Murman fluctuated within the limits of 9.3 - 10.6 cm. In the 

 White Sea the length of 1-year-old specimens (at the beginning of the second year of their life) did 

 not exceed 9 . 3 cm . 



Young herring of the generation hatched in 1937 in the region of Finnmark measured an 

 average length of 9.0 - 9.1 cm.. In the region of Kanln - 8.7 cm., in the region of Kolguyev - 7.8 

 cm., from the White Sea - 7.0 cm. The 1943 herring year class along the coast of Murman 

 reached 9.5 - 10 cm. in length at the age of 9-10 months, and in the White Sea were a maximum of 

 8 cm. at the age of 1 year. 



In 1950, the fry hatched during that year measured the following lengths in different zones 

 of the sea: in the south-eastern slope of Bear Bank - 10.5 cm. , on western Spitsbergen - 10.2 cm., 

 south-western slope of the Central elevation - 9.9 cm., northern and central zones - 9.3, Pechenga 

 Gulf - 9.3, northern slope of Gojse Bank, 8.8 cm. 



The reason for such wide fluctiiations in the rate of growth of herring fry from the Barents 

 Sea lies in factors of external environment: first of all the temperature conditions, amount of food 

 available, and duration of growing period. When studying young herring growth, we found that the 

 correlation factor between the increment of the first year and increments of the following few years 

 is extremely high. Thus, the correlation factor between 1^ and I2 fluctuated for certain samples 

 between +0 . 60 + . 50 and +0 . 70 + . 05 . We attribute the hl^ correlation between the increment of 

 the first year and increments of the subsequent years of growth to the individual peculiarities of 

 growth proper (strong specimens grow faster, whereas weak fish lag behind in their development) 

 as well as to the fact that the living conditions and rate of growth of young fish remain unchanged 

 in the course of the first 2-3 years of their existence, since we observed no significant migrations 

 during that period of time. 



Herring fry that find themselves in the northern zone of the sea remain within that zone 

 until the beginning of the return migration, similarly the fry brougjit to the shores of Murman 

 remain in littoral zones until the return movement to the west begins . 



Differences in the growth rate of young herring in different regions determine the differ- 

 ences in the dates at which the return migration begins. Return migration of adult three -year -old 

 fish developed in the western zone of the Barents Sea is more clearly pronounced than that of 

 three -year -old, slowly developing, specimens that originated in the northern or eastern peripheries 



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