CHAPTER V.
THE NATURAL AND ECONOMIC HISTORY OF THE SALMON.
The Salmon our best-known Fish—Controversies and Anomalies—Food of Salmon—The Parr Controversy—Experiments by Shaw, Young, and Hogg—Grilse: its Rate of Growth—Do Salmon make Two Voyages to the Sea in each Year?—The Best Way of marking Young Salmon—Enemies of the Fish—Avarice of the Lessees—The Rhine Salmon—Size of Fish—Killing of Grilse—Rivers Tay, Spey, Tweed, Severn, etc.—The Tay Fisheries—Report on English Fisheries—Upper and Lower Proprietors.
So many books have been written during the last few years about this beautiful and valuable animal that I do not require to occupy a very large portion of this work with either its natural or economic history; for of the two hundred and fifty kinds of fish which inhabit the rivers and seas of Britain, the salmon (Salmo salar) is the one about which we know more than any other, and chiefly for these reasons:—It is of greater value as property than any other fish; its large size better admits of observation than smaller members of the fish tribe; and, in consequence of its migratory instinct, we have access to it at those seasons of its life when to observe its habits is the certain road to information. And yet, with all these advantages, or rather in consequence of them, there has been a vast amount of controversy, oral and written, as to the birth, breeding, and growth of the salmon. There have been controversies as to the impregnation of its eggs, as to the growth of the fish from the parr to the smolt stage; also as to the kind of food it eats, how long it remains in the salt water, and whether it makes one or two voyages to the sea per annum. There has likewise been a grilse controversy, as well as a rate-of-growth quarrel. These scientific and literary combats have been fought at intervals, and, to speak generally, have exhibited the temper and the learning of the combatants in about equal proportions. The dates of these controversies are not so easily fixed as might be desired, seeing that they are either scattered at intervals throughout the Transactions of learned societies, buried in heavy encyclopædias, or altogether lost in the columns of newspapers. It is scarcely an exaggeration to say that during the past quarter of a century there has been a committee of inquiry either in the House of Lords or Commons, a royal commission, a blue book, or an Act of Parliament, every year on behalf of the salmon, besides numerous publications by private individuals.
Although no person now believes the assertion of the Billingsgate naturalist, that salmon-eggs come to maturity in a period of forty-eight hours, or that other authority who told the world that as soon as the fish burst from the ovum—a smolt six inches long coming out of a pea!—it was conducted to the sea by its parents, there is much of the romantic in the history of this monarch of the brook, and about the manner in which the varied disputed points have been solved, if indeed some of these points be yet completely settled.
I shall not again enter into the impregnation theory, having said as much as was necessary about that portion of my subject in a previous division of this work; but will proceed at once to give a summary of the parr controversy, and a few statements about the grilse and the full-grown fish as well.
According to the state of knowledge some five-and-thirty years ago—and I need not go further back at present—the smolt was said to be the first stage of salmon-life, and the abounding parr was thought to be a distinct fish. Now we know better, and are able to regulate our salmon-fisheries accordingly. The spawn deposited by the parent fish in October, November, and December, lies in the river till about April or May, when it quickens into life. I have already described the changes apparent in the salmon-egg from the time of its fructification till the birth of the fish. The infant fry are of course very helpless, and are seldom seen during the first week or two of their existence, when they carry about with them as a provision for food a portion of the egg from whence they emanated. At that time the fish is about half an inch in size, and presents such a very singular appearance that no person seeing it would ever believe that it would grow into a fine grilse or salmon. About fifty days is required for the animal to assume the shape of a perfect fish; before that time it might be taken for anything else than a young salmon. The engravings on this and the succeeding pages, which are exactly half the size of life, show the progress of the salmon during the first two years of its existence, at the end of which time it is certain to have changed into a smolt. After eating up its umbilical bag, which it takes a period of from twenty to forty days to accomplish, the young salmon may be seen about its birthplace, timid and weak, hiding about the stones, and always apparently of the same colour as the surroundings of its sheltering place. The transverse bars of the parr very speedily become apparent, and the fish begins to grow with considerable rapidity, especially if it is to be a twelvemonth’s smolt, and this is very speedily seen at such a good point of observation as the Stormontfield ponds. The smallest of the specimens given in the preceding page represents a parr at the age of two months; the next in size shows the same fish two months older; and the remaining fish is six months old. The young fish continue to grow for a little longer than two years before the whole number make the change from parr to smolt and seek the salt water. Half of the quantity of any one hatching, however, begin to change at a little over twelve months from the date of their coming to life; and thus there is the extraordinary anomaly, as I shall by and by show, of fish of the same hatching being at one and the same time parr of half an ounce in weight and grilse weighing four pounds. The smolts of the first year return from the sea whilst their brothers and sisters are timidly disporting in the breeding shallows of the upper streams, having no desire for change, and totally unable to endure the salt water, which would at once kill them. The sea-feeding must be favourable, and the condition of the fish well suited to the salt water, to ensure such rapid growth—a rapidity which every visit of the fish to the ocean serves but to confirm. Various fish, while in the grilse stage, have been marked to prove this; and at every migration they returned to their breeding stream with added weight and improved health. What the salmon feeds upon while in the salt water is not well known, as the digestion of that fish is so rapid as to prevent the discovery of food in their stomachs when they are captured and opened. Guesses have been made, and it is likely that these approximate to the truth; but the old story of the rapid voyage of the salmon to the North Pole and back again turns out, like the theory upon which was built up the herring-migration romance, to be a mere myth.