FISHING NETS, WITH SPECIAL REFERENCE TO THE OTTER-TRAWL. 579 



considerable force, and as it enters it must divide into two streams — 

 one to the right, the other to the left, because it cannot pass through 

 the knot by which the end is tied. 



The water in the cod-end tending to escape at the sides and above, 

 forms an eddy in the direction of the pockets. That this eddy must be 

 fairly strong is shown by the practice of the fishermen in having a long 

 cod-end. If the cod-end is short and dirt gets in, the fishermen get no 

 fish, and ascribe this to the dead-water or back-wash which gets above 

 the flapper and closes it. And as evidence of this one may find some 

 dirt or weed hanging above the flapper. 



With respect to the cod-end, it should be mentioned that rubbers are 

 laced to it underneath to prevent the net being chafed on the ground. 

 They are made from old net cut into strips two to four feet long, and 

 the breadth of the cod-end. They vary in number from four to eight, 

 according as the ground is smooth or rough. On smooth ground, 

 indeed, they are not necessary. 



It has been shown above that there is a strain upon the meshes 

 of the net along the central line both above and below. One result 

 of this is that the meshes of the square must be wide open ; and since 

 the meshes there are large in size, many fish must escape through them. 

 By Dr. Fulton's experiments * with cod-ends of various sizes of mesh 

 it has been shown that more fish escaped than were captured with the 

 ordinary cod-end mesh of Ih in., and when a mesh of 2| in. was used 

 all except the very largest got through. A few years ago, also, it 

 occurred to the men of the smaller Brixham trawlers that many fish, 

 especially whiting, must escape through the top of the net, which 

 at that time had a mesh of 2 A in. in the square and head of the 

 batings. To test the point they laced a portion of a herring net 

 over the square and batings, and found, just as they expected, that 

 they caught more fish in the herring net than in the trawl. They 

 consequently reduced the mesh to 2^ in. and 2 in. in the square, and 

 2 in. in the batings. Even with this size they find that a great 

 number of intermediate size of whiting — 9 to 10 in. — are meshed in 

 the batings whilst trying to escape. 



It follows from these experiments of Dr. Fulton and the Brixham 

 men that only a very small proportion — less than 10 per cent. — of the 

 round fish are taken by the otter-trawl from the water which it passes 

 through. Some might wonder why the fishermen use such a mesh 

 in the top part of the net as will allow the largest haddock to escape, 

 but the large mesh is really a necessity in the trawls as now con- 

 structed. It is different for a beam-trawl, where the mesh can be 

 suited by the speed ; but with the otter-trawl the smaller speed which 



* Eep. Scot. Fish. Board, xix., for 1900, part iii. p. 62. 



NEW SERIES. — VOL. VI. NO. 4. ^ Q 



