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1909, has an average error of 16 millions. When twice the average error is taken 

 as range, this gives as outer limits respectively 53 and 117 millions. It is but 

 little probable tliat the size of the stock lies outside these limits. The number of 

 Bnccinum, 480 barreis or ca. 2,5 millions, taken by the fishery in 1910, only re- 

 presents consequeutly V^itli of the calculated quantity of the stock. And even in 

 the most favourable case with regard to the importance of the catch, that the real 

 size of the stock is at the lowest of the limits above-mentioned, the catch is only 

 '/21; but this case is not more probable than the opposite, that the real size of 

 the stock is at the upper limit, and in tliis case the catch is but VntJi oi the stock. 



The result of these calculations thus gives us, that the number of Bnccinum 

 fished in 1010 is but a small part of the stock of whelks, and it may be said, 

 further, that great qnautities of Bnccinum live in uear the shores, where it has 

 not been possible to obtain samples with the bottom sampler; these quantities have 

 not at all been included in any of thesé calculations. 



There is reason to believe, however, that the quantity of whelks was not 

 quite as great in 1910 as in 1909; on the one haud, the 0,i m^ bottom-sampler 

 used at 200 stations did not take as many Bnccinum in 1910 as in 1909, and on 

 the other, the catch in the whelk-traps was not so great in 1910 as I had reason 

 to expect from 1909. In 1909 34 traps were taken up 7 times from the 8.— 16. 

 October, and had consequently been out as a rule but 24 hours each time; 69 

 half-bushels in all were fished. This makes 0,29 half-bushels per trap per day. In 

 the beginniug of October 1910 from the 3.— 17., however, the traps which were 

 now out for 2 to 3 days gave but 0,i9 half-bushels per trap each time; thus not 

 nearly so many; during this period no less than 1175 traps were examined. The 

 two grounds fished on lie near together; but it must be admitted, that it is difficult 

 to draw any defiuite conclusions from this material, as even a short distance can 

 affect the result, and in addition to this the nature of the bait may also be of 

 importance; both series of data however indicate the same, namely, smaller quan- 

 tities of whelks in 1910 than in 1909. The statements of the fishermen are also 

 in accordanee with these results. The whelks have not been so bad in 1910 as 

 in the year before; they have especially not damaged the fishes in the nets so 

 much in 1910 as in 1909. 



In 1908 an unusual number of small and large cod immigrated into 

 Thisted Bredning and probably into the whole Limfjord, it seems also, into the 

 whole of Denmark; people could be seeu trailing for cod in and outside Thisted 

 harbour in 1909 during the whole of the summer, something not known there 

 usually, and in 1910 the cod were still there. As these cod grew larger they 

 could devour the Bnccinum; and the contents of their stomachs distinctly show 

 that they do so on a large scale. In a cod of V4— V2 ^ kg. the soft parts with 

 operculum of as many as 6 — 7 Bnccinum were often found. It is remarkable that 

 the shells themselves of the whelks are seldom seen in the cod. I have only 

 seen this outside the Limfjord; a half digested and almost transparent shell was 

 all that was left. As we kuow how firmly the whelk is attached to its shell, we 

 caunot doubt that the cod must swallow the shell to get the soft parts; 

 the latter are not digested uutil the gastric juices have dissolved the shell. It is 

 possible that the shells are so seldom found in the somachs because I have only 



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