Page:EB1911 - Volume 27.djvu/236

 middle. Thus when in action but little of the net is vertical; the ground and head ropes, though not parallel, tend to become so, and the net trails in a curve behind them. Seen from above, the whole front margin of the net is semicircular, but the net itself is shaped like the hinder part of a trawl: in fact, did the headline of a trawl lie not in front but exactly over the ground rope, the two nets would be almost identical.

The eel drag-seine is worked from a boat, in shallow water. The extreme ends or wings are attached to two short spars, which in use are upright, and each of these is furnished with a line top and bottom which meet and are attached to the ropes by which the net is hauled in. The total length of the net is about 140 ft. from wing to wing, the length of the bag 30 ft., the depth at mouth is 20 ft. opening, the depth at the ends 6 or 8 ft.

The eel drift-net resembles the preceding, but is not drawn to an anchored boat, but drifts with the boat; it has accordingly to be made much smaller, its arms being each about 24 ft.-or a total length of 50. The wings were sometimes kept apart by the use of a floating spar, to the ends of which the seine was attached by short ropes, the spar itself being towed. A funnel-shaped valve leads into the bag. Petersen's trawl was designed by Dr Petersen for use in deep water, and for the capture of rapidly moving animals. It is essentially a drift-seine of the preceding pattern, worked Pefefsens with two small otter boards instead of a beam, and furnished with but a single warp, to which the otter boards are attached by shorter ropes or bridles. When used in very' deep water these are prevented from twisting by attaching at the point of their junction with the warp a glass float and a leaden weight. This net is undoubtedly highly suitable for great depths. It is probably the “trawl” which it has been reported has been repeatedly used in the great depth of 2900 fathoms from the Norwegian research vessel “Michael Sars,” in the course of the cruise in the Atlantic carried out in 1910 by Sir John Murray and Dr Hjort. It is practically a small otter trawl with the square cut out, leaving only wings, back part of batings and cod end, which last is entered by a funnel of netting. The meshes, in the net first constructed by Dr Petersen, were about a centimetre square in the wings and 8 millimetres square in the bag. The arms were each 24 ft. long, the bag about 16 ft. The boards were 29 in. by 32 in., and in. thick. Glass floats are frequently used with this trawl, to keep up the headline.

The Danish plaice-seine resembles the eel-seine in form, but is much larger, each arm being about 180 ft. long; the bag is 20 ft. long. The drag lines are also much longer, sometimes reaching to 1200 fathoms. These nets are worked from a very large number of boats, Esbjerg being the chief North Sea port engaged in the fishery. The vessels are yawl rigged, of the size of all but the largest smacks, and each is now furnished with a motor-boat. The boat takes the net to a considerable distance from the parent vessel, which is anchored, and shoots it in a wide curve. The drag lines are then brought back to the smack for hauling. By this method plaice are captured alive, and are kept in large floating fish-boxes until required.

Next in importance to trawling among the English fisheries is the use of drift-nets for mackerel, herrings and pilchards. It is undoubtedly the most common method of net-fishing on the coasts of the British islands, but nowhere is it so general as in Scotland. There are, however, great drift fisheries on the eastern and southern coasts of England,

and an important mackerel fishery mainly at the western end of the channel, though owing to a high import duty on mackerel levied by France this is now of far less importance. The value of the mode of fishing technically known as “drifting or driving” will be understood when it is remembered that it is the only method by which such fishes as herrings, mackerel and pilchards, which generally swim at or near the surface, can be readily caught in the open sea, at any distance from land, and in any depth of water, so long as there is sufficient for the floating of the nets in the proper position. The term “drift-net” is derived from the manner in which the nets are worked. They are neither fixed nor towed within any precise limits of water, but are cast out or “shot” at any distance from the land Where there are signs of fish, and are allowed to drift in whichever direction the tide may happen to take them, until it is thought desirable to haul them in. The essential principle of the working of the drift-net is that it forms a long wall or barrier of netting hanging for a few fathoms perpendicularly in the water, but extending for a great length horizontally, and that the fish, meeting these nets and trying to pass them, become meshed; they force their heads and gill-covers through the meshes, but can go no farther; and as the gill-covers catch in the sides of the mesh, the fish are unable to withdraw and escape. Whether it be mackerel, herring or pilchard, the manner in which the net works is the same; the variations which exist relate only to the differences in habits and size of the fish sought after.

Stationary nets, being of very small importance relatively to the preceding, must be dismissed more shortly. They are of four main kinds, viz.: stake nets, izgionary pound and kettle nets, stow and bag nets, trammel nets and hose nets.

Stake nets are usually set between tide-marks, or in shallow water, and, as their name implies, are kept up by stakes placed at intervals. They are generally set across the direction of the tide. They act as gill nets, and are chiefly used StakeNe1s. in America. In some cases a conical bag instead of a flat net occupies the space between every two stakes, forming a series of simple bag nets. This form is used on the German shores of the North Sea.