quantities of intestinal fat may be observed, 

 lated in the muscle tissue. 



The herring continue to feed, and fat is also accumu- 



During the autumn, the condition coefficient is increased considerably because of the 

 accumulation of fat. In August, this coefficient is still as high, and no decrease takes place until 

 September. The decrease is gradual for two reasons; the rate of feeding is first decreasing, caus- 

 ing a depletion of the fat reserves in order to maintain life. The intestinal fat is consumed first, 

 then the fat of the muscles. Second, energy is used for the development of the gonads. 



The increase in the food uptake is observed in May, coinciding with the ending of the spawn- 

 ing period. Spent herring dominate the catches. 



In order to re-establish the energy level the herring are fettening very rapidly. The rate 

 of feeding decreases in July. In the adult spent herring a very important physiological process 

 takes place at that time, namely, the resorption of the eggs not spawned, and of the empty follicles. 

 At the same time, the ovocytes, which shall be spawned next time, begin to grow rapidly. 



A rapid development of the gonads takes place during the following months at tlie expense 

 of the fat accumulation; in spite of that, the feeding of the herring is at that time decreasing to a 

 minimimi . 



I 



July is a critical month for the bulk of the herring, as the feeding rate decreases, while the 

 fat content and the coefficient of condition still keep the same level . 



Now the sexual organs finish their state of "relative rest", passing from stage II to III. In 

 the Barents Sea, young herring, 5-6 years old, begin their first sexual cycle. According to Marti 

 (45) the largest individuals of some year classes mature first. 



At last we will discuss a little more the change in the physiological state of the herring in 

 connection with the development of the gonads. In the autumn-winter period, the herring have a 

 high fat content and a high condition coefficient. At the same time, the gonads are developed fur- 

 ther, from stage HI to IV. The condition is decreasing by degrees until the second half of March, 

 but later it decreases very rapidly. As already mentioned, the rapid decline is explained by the 

 fact that the spawning starts in the second half of March. At this time, the herring reach the high- 

 est degree of exhaustion, decreasing considerably in weight. 



The Biological Composition of the Adult Atlantic Herring in the 

 Area near Spitsbergen 



In 1947, the first commercial -scientific expedition, consisting of 4 fishing vessels and 2 

 research vessels, was sent to the Bear Island- Spitsbergen area. The author of the present paper 

 participated in the expedition. During the cruise, 2, 000 adult herring were investigated from June 

 14, to July 10, 1947. A typical sample of the age distribution is shown in Table 13. 



TABLE 13. THE AGE DISTRIBUTION OF THE HERRING. 



246 



