On the coast of Norway the electric telegraph is applied to the herring fishery, being employed to announce to the inhabitants of the fishing towns the approach of the shoals of fish. In the fiords of Norway, where the produce of the herring fishery is the principal means of existence to nearly the entire population, it often happened that the fish made its appearance at the most unexpected times, and on some parts of the coast the shoals could only be met by one or two boats. Before the boats from the bays and fiords could take part in the fishery, the herrings had deposited their spawn and returned to the open sea.
To prevent these disappointments, often repeated with great loss to the fishermen, the Norwegian government established, in 1857, a submarine electric cable, along the coast frequented by the herrings, of a hundred miles, with stations on shore at intervals conveniently placed for communicating with the villages inhabited by the fishermen. As soon as a shoal of herrings is known to be in the offing—and they can always be perceived at a considerable distance by the wave they raise—a telegram is despatched along the coast, which makes known in each village the approach to the bay in which the herrings have established themselves.
This important branch of industry has only assumed its real character since the fourteenth century, and its sudden and prodigious extension is due to the discovery of a simple Dutch fisherman, George Benkel, who died in 1397. To this man Holland owes much of its wealth. He discovered, in short, the art of curing the herring so as to preserve it for an indefinite time. From that moment the herring fishery assumed an unexpected importance, and became the source of much wealth to Holland and its industrious and enterprising people. Two hundred years after his death the Emperor Charles V. solemnly ate a herring on Benkel's tomb; it was a small homage paid to the memory of the creator of a new industry which had enriched his native land.
The Shad (Alosa), which have the body round and more plump than the herring, are still more distinguishable by the arrangement of their teeth. More than twenty species of this genus are known, varying considerably in size. They inhabit the seas which wash the coasts of Europe, Africa, India, and America. One species is the Common Shad, Alosa communis (Fig. 384), which is found in the Channel, the North Sea, and all round our coast. It is of a silvery tint generally, greenish on the back, with one or two black spots behind the gills. The shad approaches the mouths of rivers and great estuaries, and habitually ascends them in the spring for the purpose of depositing its ova, and is found at this season in the Rhine, the Seine, the Garonne, the Volga, the Elbe, and many of our own rivers. In some of the Irish rivers the masses of shad taken in the seine-net have been so great that no amount of exertion has been sufficient to land them. It sometimes attains a very considerable size, weighing as much as from four to six pounds. The shad taken at sea are less delicate in their flesh than those caught in fresh water. The habits of the shad are very imperfectly known. Two species are found on the British coast, namely, the Twaite Shad of Yarrell (Alosa finta), which is about fourteen inches in length, brownish-green on the back, inclining to blue in certain lights, the rest of the body silvery white, with five or six dusky spots on each side arranged longitudinally. The jaws are furnished with distinct teeth; the tail deeply forked.
The second species, the Common or Allice Shad (A. Communis), is considerably larger, sometimes attaining twelve and even fifteen inches in length, having only one spot on each side of the body near the head; the jaws without teeth, the scales small in proportion. This species is plentiful in the Severn, but rare in the Thames.
Fig. 384. The Allice Shad (Alosa communis).
The shad is found in the Severn and Thames in considerable quantities about the second week in July. They reach the fresh water about May, deposit their spawn, and return to salt water in July. Their scales are large.
The Sprat (C. Sprattus) has been the subject of a great controversy, like the parr—one party contending that it is the young of the herring; another, that it is a distinct species. Pennant, Yarrell, and many eminent naturalists adopt the first view: yet its specific characters, according to Pennant, are "greater depth of body than the young herring, gill-covers not veined; teeth of the lower jaw so small as to be scarcely sensible to the touch; the dorsal fin placed far back, and the sharp edge of the abdomen more acutely serrated than in the herring." Like the herring, they inhabit the deep water during the summer, following the shoal to the sea-shore in autumn. The sprat fishing commences in November and continues during the winter months, when they are caught in such numbers that in some localities they have been used as manure.