Movements of fat herring observed in the Murman region are conditioned by strong year 

 classes abundantly represented in the littoral branch of the North Cape current. Fat herring 

 appear in the gulfs in the course of their western migration along the Murman shores. 



In Norway as well as Murman, the herring enter fjords where there is a continuous ex- 

 change of water with the adjacent section of the sea . This usually occurs during the syzygial 

 phases of the low and high tides, when the exchange of waters between fjords and adjacent sections 

 of the sea reaches its maximum . The latter factor shows that the herring enter fjords not in 

 search of some specific environment, but when conditions in the fjords become similar to the con- 

 ditions in the open sea. The movements of herring into the gulfs occur as a result of the general 

 delay of herring in littoral waters due to some peculiarities of their physiological condition deter- 

 mined by the preceding conditions of their development . 



The presence of great numbers of fat herring in the region of Iceland has been discovered 

 only recently. In Koll Bay (western coast of Iceland) during the winter of 1946/47, we caught about 

 140 thousand centners of fat herring, and in the winter of 1947/48 the catches amounted to 1,800 

 thousand centners. Prior to that, fat herring were caught in the region of Iceland in very small 

 quantities. In Koll Bay, we found herring belonging to older age groups together with the fat 

 immature herring. According to the observations of Fridriksson during the first year, the three- 

 year-old fish of the 1944 year class (43) dominated in catches; during the following season - the 

 four-year-old herring of the same year class were cau^t in greatest numbers . 



A small number of fat inunature herring is observed every year north of the island, amidst 

 the schools of older herring. The data available on fat herring from the waters around Iceland are 

 limited to the above discussed observations. 



We now wish to draw a preliminary though undoubtedly correct conclusion concerning the 

 habits of fat herring. The Murman school of fat herring concentrates in the western zone of the 

 Barents Sea . Only a small number of these fish approach the shores of Kola Peninsula during the 

 summer . Fat herring of the Norwegian school leave the coast zones and move into the open sea . 

 Undoubtedly, in the waters of Iceland, this type of herring also live at a certain distance from the 

 shores. Only isolated year classes having a low growth rate and late maturation remain in the 

 school of fat herring populating the waters off the shores. 



ISOLATION OF MATURING HERRING AND SPAWNING 



MIGRATION OF FIRST-TIME SPAWNERS. 



As mentioned above, the Norwegian scientists found no concentrations of maturing first- 

 time spawners near the shores of Norway. One or two years before the fat herring become sex- 

 ually mature, they leave the Norwegian fjords and arrive on the spawning grounds at a maturity 

 stage close to ripeness. Maturation of young herring (the oceanic stage) takes place, according 

 to Lea's scheme (56), north of the Faeroes. 



The school of fat herring is as if divided into two groups. The first group remains near the 

 shores and is formed of younger specimens, the second group lives in the open sea. It Is composed 

 of older herring and of herring having a hig^ rate of growth . 



Herring in the oceanic stage are continually in the process of attaining maturity. 



The isolation of maturing herring from the Barents Sea was already observed in pre-war 

 research in the case of the abundant 1934 year class, observations of which have been conducted 



27 



