of the summer broadens the area of its habitat by entering the northern regions, approaching them 

 both from the west and the east. This first fattening period, before reproduction, occurs in May 

 and June; then the maturing herring leave for the south coast. Apparently this departure is accom- 

 plished also along the west and east coasts, since the largest numbers of summer herring have 

 been observed by us to the north-east, and relatively few were found in the northern and central 

 regions . 



The second feeding period begins immediately after spawning. Part of the younger herring, 

 which spawn later, feeds up in the southern regions. Herring of the older stages, however, which 

 spawned first, leave for the northern regions. The herring which we found in late July, early 

 August to the north-west of Isa Fjord was moving to the north along the west coast. The feeding 

 region after spawning is considerably wider than tiiat of the pre-spawning feeding; the limit of the 

 latter may be considered 67°N, while the limit of the post- spawning feeding ground extends to at 

 least 68°N. As winter approaches, the summer-spawning herring apparently moves into the south- 

 ern regions . 



The migrations of the summer herring in the Faroes region have not yet been tracked. In 

 all probability, after reproduction the herring leave the spawning grounds in a northerly direction. 

 Their area, like that of the Iceland summer herring, is limited. Thus, in the region of Jan Mayen 

 (71 N) only occasional specimens were found in the catches. 



5. In the first year of life, the young of the summer race reach 4-4.5 cm. , in their second 

 year of life the increase in growth is 5-6 cm. In subsequent years, the growth rate of the summer 

 herring hardly differs from that of the spring herring. Summer herring reach sexual maturity for 

 the most part at 4-5 years but some individuals become sexually mature at 6-7 years. Summer 

 herring of Iceland and the Faroes are distinguished by a high fecundity. The average number of 

 ova in the summer herring is almost twice as great as in the Atlantic -Scandinavian spring herring. 



The lifetime of the summer herring reaches 15-18 years and, as an exception, one may 

 find individuals as old as 19 years. 



6. The Iceland summer herring are a race which is highly distinctive by virtue of its bio- 

 logical characteristics and above all its periods of reproduction. The times of reproduction of the 

 summer and spring herring are separated by at least two months and therefore intermixing at the 

 spawning grounds is completely excluded. 



At the same time, they have some common characteristics which are determined by the 

 conditions of their existence. Such characteristics include: growth, time of onset of sexual matu- 

 rity, and life-span. 



Future researches on the summer -spawning herring of Iceland should aim above all at dis- 

 covering the region of their pre-spawning schools. If these schools turn out to be considerable, 

 then imdoubtedly the development of the catching of this herring will be worth while . 



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