15 



intense warmth of this past summer. In August and to the middle of November 

 the fishery decreased, and in October it gave but 296 half-bushels. 



To gain an idea of the quantities of whelks caught iu the Bredning during 

 this fishery, reference may be made to fig. 8, which shows a large heap of whelks 

 thrown up on the beach east of Thisted harbour. This heap only represents 

 however the fishery of ca. 8 days iu the summer. The whelks were deposited 

 hare to die; they decomposed very quickly and spread an intolerable stench in 

 the neighbourhood. As mentioned, a part of the whelks fished was also used as 

 bait and as food for fowls; but only a small part of the quantities fished could 

 be used in this manner in the summer time. 



It soon became clear, that all the 240 traps could not be atteuded to 

 every day; this took too much time; consequently, we let them remaiu out on an 

 average for 2—3 days before taking them up; in this way more were caught per 

 trap each time thau otherwise would have been the case. As expected, it was 

 uecessary each time to move the traps ca. 10 — 20 fathoms or they fished 

 less; evidently a sign that the stock of whelks was reduced wheu the traps 

 remained at oue place for a couple of days. After some search in the Bredning 

 we found that the majority of the whelks occurred in the eastern part of Thisted 

 Bredning. All the traps were later put out here in 2 long rows at distances of 

 ca. 15—20 fathoms between each; as these rows were constautly mowed each time 

 they were atteuded to, a not inconsiderable area of the Bredning was fished over 

 in this manner, probably Vyth of that part of the Bredning which is outside the 

 6 meter line and in which the majority of the whelks live (see Chart p. 16). To 

 iuvestigate how much the stock was reduced in the summer at the piaces fished 

 over, some traps were sunk here; it then proved, that the catch iu these was only 

 Vsrd of what was fished iramediately. We cannot couclude from this, however, 

 that -/^rds of the whole stock there was really fiished away; we know, namely, 

 that not all the whelks go equally readily i[nto the traps. The experiments 

 were made during the warm period, iu July, however, when the whelks were taken 

 in greatest quantity; but we cannot know for certain, whether they will all try to 

 euter the traps at this period. 



So much can therefore be said Avith certainty, that we have not fished 

 away all the whelks on VT^ti of the area of the Bredning. 



To form any judgment of the utility of the whelk fishery gener- 

 ally, however, it is of the greatest importance to know the approximate 

 quantities of whelks found in the whole Bredning; if, namely, but a 

 small part of the number is fished away yearly, the stock will probably 

 with but little difficulty be able to replace it, and thus nothing lasting 

 is attained. 



Already in 1909, before it was quite decided to uudertake this whelk 

 fishery, 1 had arranged several experiments to test this question. 



Iu our experiments made for other purposes to determine the actual number 

 of animals per m- (□ meter) in Thisted Bredning, a bottom-sarapler was used 

 with a spread of ^ 'lo m-. Iu 1909 100 stations were investigated with this bottom- 

 sampler, and the result obtained was 1,3 Bnccinum per m-. With regard to B^ic- 

 cinum, however, the numbers obtained by means of this bottom-sampler are so 



