11 
square feet were investigated and only the oysters over 7 cm. included. On the 
east side of Feggeklit 1000 square feet were examined and 291 oysters over 7 
cm. were found; thus a little over 1 oyster per 4 square feet. The numbers on 
the actual pole-dredging banks will probably lie between these two densities; but 
as we have absolutely no chart over the extent of these banks in the fjord, 
because practically no: fishery is carried on where the smaller oysters live, we can 
for the time being form no estimate of how many million oysters of this kind 
there are in the fjord; this must be learnt in the future; but I am certain that it 
is a matter of long, narrow stretches of altogether several miles. 
It is quite different for the dredged banks on which diving is also done. 
From early times they have been numbered and mapped out by the lessees and 
inspectors in company. Such a chart has been published in my earlier Roport 
(XV). Although this chart cannot make great claims to being very accurate, as 
regards the size of the areas, yet it is possible by means of it to obtain a fairly 
correct picture of the extent or surface area over which the oyster banks in the 
Lim Fjord extend in all. This has been calculated to be 2,,, Danish square 
miles") or 1676 million (] feet. All the banks marked on the chart are included 
here with exception of those east of Løgstør. Further the large new bank, which 
embraces the three fairly large banks on the chart N.E. of Feggeklit, is included 
according to the boundaries at present known. 
In order to obtain some notion of how dense the oysters are on the banks, 
15 diving experiments were made, distributed over all the districts, as already 
described on p. 7. We were not content only with the area calculated from the 
length of line given out to the diver and the depth of water; the diver himself 
by means of a leadline measured the diameter of the circle fished over by him on 
the bottom; both metods agreed very well. The details of these experiments can 
be seen from Table IIIa. The number and length of all oysters over 7 cm. are 
represented; Table III shows likewise the number and length of the smaller oysters 
obtained by diving and it is also stated how many standard oysters there were 
according to the two standards 7 Xx 3 and 8 X 3 cm.; further, the area fished over 
is given in square feet and lastly the number of oysters over 7 cm. found per 
square foot or the density is stated. The latter varies from 0, to 0,,,, i.e. from 
0,75 per 100 [] feet to 11 per 100 [] feet. We thus see at once that the oysters 
are nowhere lying in layers on the top of one another. The expression »banks« 
should be understood as meaning banks on sand and stones on the fjord bottom 
analogous to fishing banks; the oysters themselves cannot form banks, at least 
not the living oysters. Dead shells might however be deposited on the top of 
one another generation after generation and at last form a thick layer. 
There are many oysters nevertheless on the banks. The total area of 
these according to Table IV is 1676 million [] feet. 
To come to as exact a result as possible, the density found in each district 
by diving was made the basis of the calculation as to how many oysters were 
found there. We see that the density is very low in Nissum Bredning, 0,,;; oysters 
per 100 [] feet, but large at Trehuse, Hannæs, Visby Bredning and Kaas Bred- 
1) 1 Danish square sea-mile —= 7407”? ] meters = ca. 16 Eng. square nautical miles. 
