No. 4 (1921) FISHERIES OF NORWAY 5 



Other matters of the registration and numbering of fishing boats 

 (other than open boats). 



The three scientific experts are all trained biologists. Each has 

 a definite subject assigned for investigation, the value of extreme 

 specialization having been proved here to be the only sound way 

 in the investigation of fishery problems. In deciding what line of 

 research should be followed by each expert, primary account was 

 taken of the fishes of supreme economic value to the country. It 

 was recognized that however interesting a general investigation of 

 all species of fishes may be, limited means and the necessity to 

 arrive at conclusions as quickly as possible if the fishing industry 

 were to be benefited materially, required- that eft'ort must be con- 

 centrated on definite problems. Accordingly, to one of these 

 workers has been assigned investigation of everything pertaining 

 to the life-history of members of the cod family ; the second occu- 

 pies himself with parallel researches upon the herring family, 

 while to the third is allotted the investigation of the plankton of 

 Norwegian seas.' The work done by the last named is largely 

 complimentary to that of the second, for it is upon the seasonal 

 abundance of plankton that most of the movements of the herring 

 (.lepend. Study of plankton is also necessary for the extension of 

 our knowledge of the larval histories of the great majority of our 

 food fishes ; the herring is almost the only exception to the rule 

 that the eggs of food fishes are pelagic, floating freely in the surface 

 waters of the sea. The study of plankton is further bound up with 

 the physical and chemical investigation of variations in the 

 density, temperature and chemical character of sea water, as these 

 factors influence and control the abundance particularly of the 

 plant organisms present, which in turn controls the abundance or 

 scarcity of the small animals that feed on this food. The greater 

 part of these investigations is carried out in the laboratories of 

 the department's headquarters at Bergen. The advantages of 

 carrying on these researches at headquarters, where there are the 

 best facilities for reference to literature and for intercommunion 

 with other workers, are deemed sufficient to outweigh the advan- 

 tages of work in an outstation laboratory in the midst of the parti- 

 cular fishery to be studied, for such a location means the isolation 

 of the worker, delay in procuring literature and the loss to the 

 Director of the advantage of frequent discussion with the expert of 

 the problems on hand. The last named ( onsideration is valued 



