32 



Part III. — Twenty-first Annual Report 



greater than the width of the beam-trawl. Since the width of the 

 mouth of the beam-trawl is constant and known, viz. fifty feet six inches, 

 the width of the mouth of the otter-net at the ground would then be 

 about sixty-one feet six inches. In this instance the length of the head- 

 line between the otter-boards was 140 feet, and, on the supposition above 

 stated, the arc of the line in fishing would absorb over 78 feet, the 

 proportion of the distance between the boards to the length of the head- 

 line connecting them being as 1 to 2*2. This is not very greatly different 

 from the results of the experiments with the small nets of the " Garland " 

 last year,* where the ratio of breadth to length of head-line was found to 

 be as 1 to 1'9, and the calculated width of the mouth of a large otter-net 

 with a head-line of 130 feet was placed at 68| feet. 



No certain conclusion as to the precise fishing- width can, however, be 

 based upon a single experiment, but the result, so far as it goes, 

 supports the opinion I previously expressed, that the spread of the 

 otter-ti-awl on the ground is much less than is usually supposed. It 

 will be noticed, moreover, in the above experiment that the proportion 

 of the various species of flat-fishes varied considerably in the two cases, 

 plaice giving the majority in the catch of the otter-trawl and dabs in 

 the catch of the beam-trawl. The circumstance shows that the ground 

 worked over in the two drags was not quite the same ; the slight excess 

 of long rough dabs in the catch of the beam- trawl probably indicates 

 that it was conducted on the whole in somewhat deeper water. 



The difference in the catch of the round-fishes in the two cases is 

 very marked. The beam-trawl caught 889 and the otter-trawl 2534, or, 

 allowing twenty codlings for the quarter-basket, 2554. The proportion 

 was thus 1 to nearly 2*9, as compared with 1 and 1-22 in the case of the 

 flat-fishes. The greatest proportional increase was in cod — but the 

 numbers were quite small, — and next in haddocks, which formed the 

 great bulk of the catch. The result agrees with the conclusion pre- 

 viously reachedjt that the arc of the head-line in fishing is not horizontal, 

 but rises high in the water, and thus takes many of the active round- 

 fishes that were above, or got above, the beam of the beam-trawl. 



The third haul in Aberdeen Bay was with the otter-net, in from ten 

 to eighteen fathoms, ofi" Collieston, and the catch was a heavy one, con- 

 sisting for the most part of 23 1 baskets of haddocks — all but half a 

 basketful being small or " thirds," — four baskets of whitings, 3| of 

 codlings, three of plaice, and half a basket of dabs, as well as five cod, 

 three turbot, and two black soles. The latter is a very rare fish on the 

 east coast of Scotland, but one or two are occasionally taken while 

 trawling in the bays and firths. 



The number of fishes caught in the three hours and twenty minutes 

 during which the drag lasted was 7023, perhaps the largest in the 

 records, owing almost entirely to the quantity of small haddocks, w-hich 

 were extremely abundant last autumn over almost the whole of the 

 North Sea. Of the total, 6732 were marketable and 291 unmarket- 

 able. The codling taken were also exceptionally numerous, viz. 623, of 

 which 578 were marketable. The haddocks numbered 5098, all but 

 eighteen marketable, but there were only thirty-two large ones, or 

 " firsts," and fifty-two mediums, or " seconds," the small or " thirds " 

 numbering 4996. Whitings were numerous — 772, of which 690 were 

 marketable. The details of the catch are as follows, I. representing the 

 marketable and II. the unmarketable fishes : — 



* Twentieth Ann. Rep., Part III., p. 122. 

 t Loc. cit. 



