The main 

 problems 



_ VII — HOEK- INTRODUCTORY 



of the International Conncil, which met at Copenhagen in July 1902, were directed R«o'""°"s of 



, . T the Copenhagen 



to this end." ■ Meeting 



Two main questions then appeared specially in the forefront, both of which 

 were regarded as of extraordinary importance, both from the economical as from 

 the general scientific standpoint. Whilst the various investigators now utilize the 

 greater means at present at their disposal for the investigation of numerous other 

 questions of general marine biology, material is being collected at the same time 

 for the solution of these main problems. This material is worked up more or less 

 by a specialist appointed by the International Council, in part sent also to the 

 Bureau for further elaboration. 



The problems placed in the foreground by the first meeting of the International 

 Council, were: 



a. the problem of the migrations of fishes, and 



b. the problem of so-called overfishing. 



A short description of the importance of these problems and what is expected 

 from their solution, ma}' be allowed here. 



The migrations of fishes. On the formation of Committee A (see p. 7 of ^iie migrations 

 this Report), two of the principal food-fishes for the North Sea and Norwegian Sea 

 fisheries were chosen as examples of fishes whose migrations should be specially 

 studied: viz. the herring and cod. It was not expected, that the investigations 

 would be restricted entirely or even mostly to these, but there was a well-grounded 

 hope, that the results of the investigations regarding these two species, would 

 also be valuable for the elucidation of the migration-problems in general and thus 

 for manj^ other species. The choice made was also a very good one; the herring 

 and cod in themselves belong to the most important food-fishes occurring anywhere, 

 and, at the same time — so far as present experience goes — the}- belong in many 

 ways to two quite different types of migratory fishes. 



The herring is a so-called pelagic fish, which, like many of its allies (sardine T^e herring as a 

 anchovy, shad etc.) undertakes migrations and collects in shoals at a certain period '"'°'"°'^ 

 of the year, and thus forms the objective of a fisher)-. It is specially characteristic 

 of these fishes, that they do not occur on the same fishing grounds the whole 

 year through, but are met with only at a certain season. For example, the herring are 

 found on the western side of the North Sea, off the Shetland Isles, at the end of 

 June, off Newcastle in September, and in the southern part of the North Sea in 

 November. Similar differences occur on the eastern side of the North Sea as far 

 as the Skager Rak: on the Bohuslän coast, the herring can be found from Sep- 

 tember to February; on the Norwegian coast, especially between Stavanger and 

 Kors Fjord, the so-called spring-herring (Vaarsild) is caught in February and 

 March, whilst the fishery of the so-called summer-herring (Fedsild) takes place 

 exclusively in the summer and autumn months, and, as a rule, on the coasts of 

 the northern provinces of Norway. 



These are but a few examples, which might easily be added to from the inves- 

 tigations made by Heincke on the races of the herring; wherever a herring race 



■ Rapports et Procès Verbaux. Vol. I. Procès- Verbaux des réunions du Conseil p. 16-19. 



