254 



0. Nordgaard. 



A glance at a curve depicting the yield of this fish (ef. Hjoet, 

 Hvalfangst og fiskeri, p. 81) gives the impression of great irregul- 

 arity, without any sign of any rhythmical law. It must, however, 

 be remembered that there are many things which affect the yield 

 of a fishery. It cannot be denied that there are immense variations 

 in the occurrence of capelan, and this cannot be supposed to be a 

 whim on the part of the fish, but must depend upon variations in 

 the natural conditions in the sea itself. When I visited Finmark, 

 in 1899, M. Ingebeigtsen, the whale-catcher, told me that old 

 fishermen took two things as signs of a good number of capelan, 

 and these were (1) a plentiful supply of driftwood, and (2) a good 

 ptarmigan year. 



Carefully considered, it will be found that these two „signs" 

 point to the fact that sea winds have been prevailing; for the 

 drift wood is driven by wind and storm landwards, and prevailing 

 winds from the ocean means a good deal of moisture which here 

 falls as snow, and a good deal of snow in the mountains sends the 

 ptarmigan down into the low lands. If it be taken for granted 

 that the capelan, as well as the herring, is dependent upon the 

 movements of the surface layers, my hypothesis would mean that 

 in the years when there is a plentiful downfall, there would be 

 large shoals of capelan. This does not, however, seem very likely 

 from the statistics given for the years 1896—1902, during which 

 period there was a surplus downfall, but only a poor yield of fish. 

 But Phoca groenlandica occurred in large numbers in the years 

 mentioned, and the presence of this animal was said to have a 

 particularly bad influence on the fishery. 



According to Bbemee there was, from 1830 — 38, good skrei- 

 tishing in the fiords of Finmark. but then Ommatostrephes and 

 herrings showed themselves and the skrei diminished in numbers. 

 The same writer says that the capelan. about the year 184o, again 

 came in large numbers to the coasts of Finmark. 



I have already shown that the ,,skrei"-fishery and the winter 

 herring-fishery appear to depend upon contrary current-phases, and 

 as the eapelan's habits are, as far as is at present known, similar 

 to those of the herring at the time of inflow, we must expect that 

 the surface currents, which drive the capelan landwards, cause 

 compensation currents further down, and these latter obstruct the 

 inflow of „skrei". "What I have just said must only be taken as 

 an attempt at an explanation. It is, meanwhile, interesting that 

 this attempt harmonizes with the prognostications made by old 

 fishers in Finmark. 



At any rate it would seem to be worth while to pay attention 

 to those mechanical factors which may be supposed to exert an 

 influence on the yield from the fisheries. 



It is possible that it will be found that the large catches of 

 herrings on the coast in the months of October — December, and 

 to some extent also January, may be accounted for by the fact 

 that meteorological conditions in these months cause a strong flow 

 of water to the coasts, which is also evident from there being a 

 maximum height of water in the autumn. And with regard to the 

 spawning herring (vaarsild) and the spawning cod (skrei), I think 

 I have found as a result of historical and statistical investigations, 

 that, as a rule, a good herring fishery and a good „skrei"-fishery 

 will not occur on the same stretch of coast, simultaneously. At 

 the period these fisheries are carried on (January — April), there is 

 a sinking tendency in the water towards the spring minimum, and 

 it seems reasonable, that just as the relation between ocean and 

 land winds at this time exerts an influence on the medium water- 

 level, by regulating the currents in the coast water, so will its 

 effect on the currents also, to some extent, further or hinder the 

 inflow of cod and herrings. There can be no doubt that biological 

 and physical factors play an important part in the fisheries. The 

 former may be taken to be constant, while, at any rate, some, of 

 the physical ones are variable. 



If one takes it for granted that the ocean-currents have an 

 important influence on the course of the fish towards land, the 

 difficulty meets one that scientists are not agreed as to which of 

 the causes of currents one should aive most weight. Can it. how- 

 ever, be proved that there is a connection between the periodical 

 changes in the yield of the fisheries and the fields, one will be 

 compelled to suppose that there is a common cause at the bot- 

 tom, and we have thus come to the conclusion that this must be 

 the variations in atmospheric pressure. But we get no farther, and 

 will hardly be able to do so, until meteorologists have solved the 

 problem of the laws governing the rise and changes in barometrical 

 minima. 



As far as practical marine investigations are concerned, the 

 following famous words of Laplace may well be used: — 



„Ci '/(" nous savons est jieu de chose, ee que nous ignorons 

 est immense." 



