year 1951 showed a migration of small Kandalaksha herring to the Tersky shore, and also south- 

 wards, to the region of Keret'-Gridino. The numerically strong 1948 year-class, when four years 

 of age, was caught soon after the end of the spawning period in great quantities on the Tersky 

 shore, west of the village of Tetrino. 



At the present time, marking has demonstrated the migrations of small Kandalaksha herr- 

 ing. In May and June 1954, at various points of the Tersky shore - from the river Kuz to the mouth 

 of the Varsuga - herring were caugjit which had been marked at the end of April and beginning of 

 May 1954 in the inner part of the Kandalaksha Gulf, in the Palkina, Valas-Ruchey and Knyazhaya 

 inlets /Vilson {1)7. 



However, the extension of the area of distribution of the small Kandalaksha herring is 

 limited to the coastal zone; in the open region of the central part of the White Sea, fishable concen- 

 trations of tliis fish have not been found. Our observations on the 14th voyage of the "Tropik" and 

 the findings of search vessels have shown that in the summer of 1951 in the region of the Tersky 

 bank this herring was caught only by shore-fishing gear, but was almost absent from the hauls of 

 drifter nets . 



Another characteristic peculiarity of the biology of the small White Sea herring is their 

 comparatively short life-span. Only the small Kandalaksha herring live as much as ten years, 

 whereas the other small herring have a shorter life-cycle. The life-cycle of the Onega herring is 

 limited to eight years and that of the Dvina herring to six. 



The most important small herring for fishery, however, are: the Kandalaksha herring - 

 up to 6 years of age; the Onega and Dvina herring - up to 5 years. 



The fertility of the small White Sea herring is not great. In the Kandalaksha herring, for 

 three -year -old fish it is 3-4 thousands; for four -year-old fish, 6-7 thousands; and for five-year- 

 old fish, about 12 thousand eggs. During its whole life, one female of the small herring produces: 

 Kandalaksha herring, 25-30 thousand; Onega, 20-23 thousand; and Dvina, around 20 thousand eggs . 

 In comparison with other herring (Atlantic, Caspian), the White Sea herring are markedly less 

 fecund . The change in fecundity in connection with the general weight of the fish in the White Sea 

 herring has been already studied /Bezrukova (bj^. 



The reproduction of the White Sea herring takes place in a narrow coastal zone at a depth 

 of 2-5 metres, chiefly at a depth of 2-3 metres. In spite of the fact that the coastal character of 

 the reproduction of these herring has been known for a long time, Dmitriev (9) nevertheless sug- 

 gested the possibility of the spawning of White Sea herring far from the shore. He also (11) con- 

 sidered possible the autumn -spawning of White Sea herring. More recent researches have not 

 upheld these suppositions. 



Searches for the spawning-places of small White Sea herring in the Dvina Gulf and in the 

 eastern part of Onega Gulf and of large herring in Kandalaksha Gulf and in the region of the Solo- 

 vetsky Islands, which were carried out by us in post-war years, also showed that the spawning of 

 these fish takes place in the narrow coastal belt at a depth of no more than 5 metres . 



Spawn of the small herring was found in the region of the Letni (Summer) shore and in the 

 inlets of Unskaya and Yandovaya (Dvina Gulf), on the Seldyanye Ludy, at Kiy Island and in Pokrov- 

 skaya Inlet (Onega Gulf); the spawn of large herring was found in the region of the Solovetsky 

 Islands (Glubokaya Inlet and other places) and in Kandalaksha Gulf (Kiberinsky shore) . All the 

 spawning -places of White Sea herring thus discovered are situated in the coastal zone at depths of 

 from . 5 to 5 metres /Altukhov (4]7. 



274 



