The spawning time of the summer herring in Icelandic waters can be particularly well 

 determined from the observations of post-spawning individuals by months. In June 1949, herring 

 (with gonad maturity stage VII-II) which had reproduced in the spring were dominant. 



In the first half of July, their numbers fell to 30% and in the second half to 17%. In August 

 and September, the number of individuals having completed spawning (stage VII-II) increased to 

 42-46%. 



In 1950, at the beginning of June, post-spawning individuals with gonads in the process of 

 being restored (stage VII-II) numbered from 40% to 60%. The number of fish which had recently 

 completed spawning increased considerably. In one sample taken after 22nd July, they comprised 

 95%. The specific weight of post-spawning individuals in the sample remained high even in August. 

 Thus, on the 9th August in the region to the north of Grimsey Island they comprised 90.5%. In 

 September, percentages of this type fell to 30-40. 



In the first catches of 1951, taken to the north-east of the island, herring with developing 

 gonads (VII-II) were dominant in June - 74.4%. In July, their specific wei^t fell to 2.6%; on 

 August 2, herring which had just finished spawning comprised 73%. In the second half of August 

 and in September, their number dropped sharply. 



No eggs of summer -spawning herring were found in the region of Iceland and the Faroes. 

 According to published material, fertilized eggs of the summer herring have been found off Green- 

 land by Hansen(9) and fertilized eggs of the spring herring to the south of Iceland by Fridriksson 

 (6). Hence the location of the spawning grounds, the times of reproduction, and hatching-out of the 

 larvae can be established merely on the basis of the early stages of larvae less than 10 mm. in 

 length, the distribution of which is a reliable index of the spawning regions. 



During I. Schmidt's researches-' from 1903 to 1908, larvae were caught from April to 

 September. The number of larvae caught was at its lowest in May and June. A small number of 

 larvae of this herring was obtained by Taning (17) as well in May and June, during the first period 

 of his investigations (1924-34). Later (1939-41, 1946, 1950), TSnIng (18, 19, 20) collected larvae 

 only in the second half of the summer. Data about larvae less than 10 mm. in length are given in 

 Table 1. 







In June, neither Schmidt nor Taning found larvae of less than 10 mm. in length. The largest 

 number was found in July. Particularly large numbers of larvae were taken by Taning in this period 

 from 1924 to 1934 and again in 1939. 



On the 18th July 1903, Schmidt discovered larvae of the simimer herring less than 10 mm. 

 in length above a depth of 65 m. off the southern coast of Iceland (Figure 2). On the 29th and 30th 

 August 1904, he cau^t larvae of the same dimensions in the region of Cape Reykjanes and to the 

 south-west of that cape and also near Cape Snaefellsnes.^ 



In 1925, early stages of larvae were found by Taning in August above 74 m. in the region of 

 Cape Snaefellsnes . 



In 1927, Taning also caught small herring larvae at three points in the region of Westman- 



naeyjar Island, off Cape Reykjanes and off Cape Snaefellsnes above depths from 33 to 121 m. 



\J According to Jespersen's work (14). 



2/ Western part of the peninsula, separating Faxa Bay from Breida Bay. 



169 



