Page:EB1911 - Volume 27.djvu/235

 rope resembles that in the beam-trawl, but is in some cases furnished with chains or “dangles” or with “bobbins.” Bobbins are heavy cylindrical wooden rollers, threaded on the wire warp which forms the core of the ground rope: they are of two sizes (the larger a foot through) placed alternately to ensure freedom of rotation. Their object is to surmount or crush obstacles which, by catching the ground rope, might capsize the trawl boards and destroy the success of the haul; they are accordingly used only on rough ground. The chains are fastened to the ground rope in loops, to give it weight, and are used on very soft ground to ensure the trawl's effectually dislodging the fish. The headline is a rope some 3 in. in circumference.

The meshes are, from knot to knot when drawn taut, from 5 to nearly 6 in. in the square and wings, 5 to 4 in. above, and 5 to rather over 3 in. below in the extreme back of the under batings called the “belly,” about 2 in. in the cod end.

The successful shooting of the net is a matter of great skill. The paying out of the net, the lowering of the boards, the running out Working of unequal lengths of the two warps to square the the Net trawl into proper position and the subsequent lowering of the whole to the bottom, resemble the corresponding operations with the beam trawl. The fore warp is then drawn close to the quarter of the vessel and shackled to the after-warp close to the vessel’s side, and the vessel proceeds on her course at a speed of some 2 or 2 m. per hour. The length of haul made varies enormously. On a ground where fish is very abundant, as in the early days of Iceland fishing, it may be half an hour or less: on the Eastern Grounds, off Denmark, where the great English fleets usually work, it is about 3 hours. When about to haul, the fore warp is released from the shackle and the vessel is immediately steered towards the side from which the trawl has been towed, while the warps are rapidly wound in; the warps thus speedily come to stand at right angles to the vessel. If this were not the case they might probably foul the vessel’s propeller, with very serious and possibly fatal consequences to her safety. The trawl boards, having been drawn right up to their powerful iron supports or gallows, remain suspended there if the trawl is to be re-shot while the net is emptied; they are otherwise lowered between the gallows and the bulwark, and secured. The hauling in of the catch occurs as in the beam-trawl. Trawlers carry a trawl on each side of the deck, and in continuous trawling these are worked alternately. On each side of the deck a square enclosure called a pound is made for the reception of the fish falling from the cod end, by fitting planks turned on their sides into stanchions grooved for their reception. The fish is sorted into baskets in the pound, cleaned and packed in trunks in ice in the hold or fish-room.

A noteworthy method of trawling is the custom of 50 or 60 boats fishing together in a fleet. All these vessels will trawl as directed by an “admiral,” in proximity to a “mark-boat,” whose position is known to the owners from day to day, and the fish is daily fetched to market by fast “carriers.” There are four such fleets of British vessels working in the North Sea. It is also worthy of mention that wireless telegraphy has recently been fitted to several German trawlers and drifters, which can thus communicate with the fishery protection cruisers, who pass on information concerning the fishery, and with the shore. The practice will doubtless spread, although as yet the distance over which a message can be sent by these vessels is very small.

The use of steam has not only increased the radius of action of the vessel, but by facilitating the process of hauling enables trawling to be carried out in greater depths. The sailing worked vessels rarely work in greater depths than 30 fathoms. The steam vessels work frequently (e.g. south of Ireland) in over 200 fathoms. Commercial trawling in 500 fathoms is not unknown, and the Irish research vessel “Helga” works in as much as 800 fathoms.

The movable nets resembling trawls are seines, from which trawls were in all probability developed. The seine is an extremely ancient net, used by Phoenicians, Greeks and other Mediterranean peoples, the word seine being derived from the Greek name ( ) for the appliance. In essence it is a long strip of netting with a buoyed headline and weighted ground rope. It is taken out in a boat some little distance from the shore, paid out during the boat’s progress, and the lines attached to the ends being then brought back to the shore, the net is hauled up on the beach. From this simple form, which is still in use for the capture of smelts and other small fish, numerous developments have occurred. Before mentioning the details of a few of the chief of these it may be said that the changes mainly consist in the formation of a purse or pocket in the middle of the net, somewhat resembling the cod end of a trawl, and in the working of the net from boats or ships instead of from the sea. The boat is anchored during the hauling, the net being drawn to it. A net with a wide spread, furnished with a purse, drawn over the sea bottom to a boat, is obviously very near a trawl in its action. When in the late ’eighties Danish fishermen fastened otter boards to their plaice-seines, and allowed the boat to drift, the seine was dragged by, not to the boat, and when Petersen used a similar arrangement, presently to be described, dragged like a trawl, the evolution of a trawl from a seine was practically complete. Some such process, with the use of a beam instead of otter boards, probably occurred in the past and resulted in the beam trawl.

Pilchard seines, as the most elaborate forms of simple seines, may be briefly described. The pilchards approach certain parts of the Cornish coast, notably St Ives and Penzance, in shoals which are eagerly awaited; and when they are sufficiently near two boats start out on the fishery. One carries a short seine, the stop net, which has previously been joined to the large seine, and shoots this net as it rows towards shore. The other rows along the shore, shooting its net as it goes. Ultimately the boots turn to meet each other, and when they do so the ends of the long seine are joined, the stop net removed, and the circle of netting towed to the beach until its ground rope touches the bottom. The pilchards are then removed at leisure by a smaller seine called a tuck-net-seine being a word which in the west of England is confined to nets worked from the beach. This net is very deep in the middle, and as the foot rope is drawn well in in hauling, a floor is formed for it as it approaches the boat from which it is worked, a simple form of purse or bag resulting. The pilchards are dipped out in large baskets. In a good catch this process of “tucking” out the fish may be carried on for some days. The long seine used may be 200 fathoms long, and is about 6 fathoms deep at the ends and 8 fathoms in the middle. The tuck-net is about 80 fathoms long, 8 deep at the ends and 10 fathoms in the middle. The meshes are larger at the ends or wings than in the middle, as in the trawl, bringing a tuck-net from 30 down to 42 the yard.

The seine is far more used in the United States than in the British Islands, its operations being so successful that complaints have in some cases been made that local fisheries for certain species have been entirely destroyed owing to the diminution of the fish which it has brought about. It is used in water of any depth, for the purpose of catching mackerel. Rings are fastened to the ground rope, and by means of a rope passed through these rings the lower margin of the net is drawn together, converting the circle of netting into a complete basin shaped purse. The slack of the net is then gradually drawn in, the fish collecting in the last of the net (the fullness or “bunt”) to be reached. Purse seines are also used in Japan, where there is also in use a net which is a combination of seine and pound-net. A long wall of netting forms a “leader” to the fish, and ends in an oval enclosure formed by a purse seine with incompletely closed ends. Two anchored boats, to which the seine is lashed, keep it extended. On hauling, the opening is closed and the slack of the net hauled into one boat, which approaches the other, until the final portion containing the fish is brought to the surface.

The pockets of seines, though answering the same purpose as those of trawls in preventing the escape of the fish, resemble not the Dockets but the cod end of the latter net. In the filets de bœuf of the Mediterranean the pocket is a very long bag, trailing behind the arms of the seine, and constricted for some distance before joining it. It is without “flapper” or other valve. (After Drechsel.)

. 2.—Diagram of a Danish Plaice-seine at work.

Most efficient pocketed seines are used in Denmark for the capture of eels and plaice. In both these nets the depth increases rapidly as soon as the extreme wings are left, and is very great in the