GENERAL CHARACTERISTICS OF THE NORTHERN SEAS 37 



temperatures at various depths in one of the fjords on the southern point of 

 Greenland is given in Table 9. 



Table 9 



n , Temperature of water in °C 



Similar changes in the fauna and especially in the fish population have 

 taken place in the waters of Iceland. 



Many fish, such as caplin, herring and cod, the great bulk of which have 

 hitherto inhabited the warmer southern and western shores of the island have 

 migrated to the northern shores and begun to spawn there. Fish formerly 

 rare in Icelandic waters have now become common. They include tuna, 

 mackerel, Selache maxima, Scombresox saurus, Orthogoriscus mola, Paralepis 

 kroyeri and many others. Such southern forms as, for instance, Notidanus 

 griseus, Xiphias gladius and Caranx trachurus, which have never before been 

 observed in Icelandic waters, have been found there in recent years. 



The same can be said about the invertebrates. Formerly unknown off the 

 shores of Iceland, there have now appeared there Echinus esculentus, Aphrodite 

 aculedta, Lithodes maja, and the huge south boreal polychaetes {Nereis virens), 

 which, by the way, was found in the White Sea in recent years (Annenkova and 

 Palenichko, 1946) and was undoubtedly absent from those waters before. 



Not only marine animals but birds are extending their habitats northwards 

 because the climate is becoming milder. Some North-European gulls {Larus 

 ridibundus, L. fuscus and L. argentatus), which used to be rare in these parts, 

 have in recent years appeared in great numbers in Iceland. 



Ice has disappeared from the northwestern, northern and eastern shores of 

 Iceland in recent years, the winter has become very mild, the average air 

 temperature in February and March has risen by 4° to 7° above the former 

 average, while the temperature of the surface waters along the northern and 

 western shores has risen by 0-5° to 4°. This rise in temperature is felt to depths 

 of 200 to 400 m; hence the difference between the temperatures of the 

 northern and southern shores of Iceland has practically disappeared. The 

 same phenomena are observed at Jan Mayen I., Spitsbergen and in Arctic 

 bodies of water situated to the east of them. In the 1870s and 1880s there was a 

 fairly good catch of cod and haddock along the western shores of Spits- 

 bergen. Later this fishing stopped completely to begin again in the third decade 

 of the present century. About 200 small Norwegian trawlers fishing in these 

 waters in 1935 obtained a total catch of 4,500 tons offish. N. Tanassijcuk 



