Blackwood's Edinburgh Magazine — Volume 54, No. 333, July 1843

by Various

On the subject of salmon leaps, most of us have both heard and seen much that was neither new nor true. Mr Yarrell, a cautious unimaginative man, accustomed to quote Shakspeare as if the bard of Avon had been some quiet country clergyman who had taken his share in compiling the statistical account of Scotland, confines their saltatorial powers only within ten or twelve perpendicular feet. We hold, with Mr Scrope, that even this is probably much beyond the mark. He thinks he never saw a salmon spring out of the water above five feet perpendicular.

"There is a cauld at the mouth of the Leader water where it falls into the Tweed, which salmon never could spring over; this cauld I have lately had measured by a mason most carefully, and its height varies from five and a half to six feet from the level above to the level below it, according as the Tweed, into which the Leader falls, is more or less affected by the rains. Hundreds of salmon formerly attempted to spring over this low cauld, but none could ever achieve the leap; so that a salmon in the Leader water was formerly a thing unheard of. The proprietors of the upper water have made an opening in this cauld of late years, giving the owner of the mill some recompense, so that salmon now ascend freely. Large fish can spring much higher than small ones; but their powers are limited or augmented according to the depth of water they spring from. They rise rapidly from the very bottom to the surface of the water, by rowing and sculling as it were with fins and tail, and this powerful impetus bears them upwards in the air. It is probably owing to a want of sufficient depth in the pool below the Leader water cauld, that prevented the fish from clearing it; because I know an instance where salmon have cleared a cauld of six feet belonging to Lord Sudely, who lately caused it to be measured for my satisfaction, though they were but few out of the numerous fish that attempted it that were able to do so. I conceive, however, that very large fish could leap much higher."—P. 12.

We believe that a good deal of the contrariety of opinion which prevails on this subject, arises from anglers and other men confounding an inclined plane with a perpendicular height. Salmon will assuredly overcome a prodigious force of descending water,—a roaring turmoil, which presents from below the aspect of a fall, but consists in reality of separate ledges massed together into one, when "floods lift up their voices." We are sorry to say, however, that the entire practice of angling is pervaded by a system of inaccuracy, exaggeration, and self-deceit, which is truly humiliating. There is consequently no period in the life of a young person which ought to be more sedulously superintended by parents and guardians, than that in which he is first allowed to plant himself by the rivers of waters. The most wonderful feature, however, in the leaping of salmon is not so much the height to which they spring, as the ease, elegance, and certainty, with which, while ascending small cataracts, they make their upward movements. For example, near Oykel bridge in Sutherland, there is a rocky interruption to the more ordinary current of the river, where the water is contained, as it were, in stages of pots or little caldrons, over the lower edge of each of which it dances downwards in the form of a short perpendicular fall. From a neighbouring bank by the river side, the movements of the aspiring fish may be distinctly seen. When a grilse has made his way to the foot of one of these falls, (which he never could have ascended before, although he must have descended it in childhood on his seaward way,) without a moment's doubt or hesitation he darts into the air, and throws himself head-foremost into the little basin above, to the bottom of which he instantly descends. Nothing can be more curious than the air of nonchalance with which they drop into these watery chambers, as if they knew their dimensions to an inch, and had been in the habit of sleeping in them every night. Now, from what has been ascertained of the natural history of the species, although the adult salmon of the Oykel must have previously made the leap at least once before, no fresh-run grilse could have ever done so; and yet, during suitable weather in the summer season, they are sometimes seen springing along with all the grace and agility of a troop of voltigeurs. Their object of course is to rest themselves for a short time, before leaping into the second range from the ground floor. But this innocent intention is too often interfered with; for a sharp-sighted Highlander, stationed on the bank above, immediately descends with landing-net in hand, and scoops them out of their natural caldron, with a view to their being speedily transferred to another of more artificial structure—the chief difference, however, consisting in the higher temperature of the water.

"Salmon," says Mr Scrope, "are led by instinct to select such places for depositing their spawn as are the least likely to be affected by the floods. These are the broad parts of the river, where the water runs swift and shallow, and has a free passage over an even bed. There they either select an old spawning place, a sort of trough left in the channel, or form a fresh one. They are not fond of working in new loose channels, which would be liable to be removed by a slight flood, to the destruction of their spawn. The spawning bed is made by the female. Some have fancied that the elongation of the lower jaw in the male, which is somewhat in the form of a crook, is designed by nature to enable him to excavate the spawning trough. Certainly it is difficult to divine what may be the use of this very ugly excrescence; but observation has proved that this idea is a fallacy, and that the male never assists in making the spawning place: and, indeed, if he did so he could not possibly make use of the elongation in question for that purpose, which springs from the lower jaw, and bends inwards towards the throat. When the female commences making her spawning bed, she generally comes after sunset, and goes off in the morning; she works up the gravel with her snout, her head pointing against the stream, as my fisherman has clearly and unequivocally witnessed, and she arranges the position of the loose gravel with her tail. When this is done, the male makes his appearance in the evenings, according to the usage of the female. He then remains close by her, on the side on which the water is deepest."—P. 15.

During this crisis trout collect below to devour such portions of the spawn as float down the river, and parr are frequently seen hovering in and around the trough. All these parr are salmon fry of the male sex, in a state of maturity; and if the old gentleman chances to be killed, or driven away, without having provided an assistant or successor, the "two-year-olds" perform the functions of paternity. This circumstance, though overlooked by modern naturalists till the days of Shaw, (not the old compiling doctor of the British Museum, but the more practical "keeper" of Drumlanrig,) was known and described by Willoughby in the seventeenth century. "To demonstrate the fact," says the more recent observer, "in January 1837, I took a female salmon, weighing fourteen pounds, from the spawning bed, from whence I also took a male parr, weighing one ounce and a half, with the milt of which I impregnated a quantity of her ova, and placed the whole in a private pond, where, to my great astonishment, the process succeeded in every respect as it had done with the ova which had been impregnated by the adult male salmon, and exhibited, from the first visible appearance of the embryo fish, up to their assuming their migratory dress, the utmost health and vigour."

So serious is the destruction of the spawn and fry of salmon, both by sea and fresh-water trout, that the Duke of Sutherland's manager would willingly, were it possible, extirpate the entire breed of these fish. "They commence," he informs us, in a letter of 15th May 1843, "the moment the salmon begin to deposit their spawn, and in the course of the spawning season they devour an immense quantity of ova. Indeed, at all other times of the year, they feed on the fry of salmon, and continue their destruction till the day the smolts leave the rivers. I have often cut up trout, and got smolts in their stomach; and last week a trout was opened in Mr Buist's fish-yard with four full-grown smolts in its belly. From these and other similar occurrences, you may judge to what extent this destruction is carried on, in the course of a single year, in such a river as our Oykel, where I have killed seven hundred trout at a single hawl." We understand that, some years ago, when Mr Trap, (a most appropriate name,) the fishmonger in Perth, had the Dupplin cruives, he got about 400 whitlings (or sea-trout) in one day, all of them gorged to the throat with salmon fry. The sea-trout of Sutherlandshire, like those of the Nith and the Annan, almost all belong to the species named Salmo trutta by naturalists. They scarcely ever exceed, indeed rarely attain to, a weight of five pounds; and such as go beyond that weight, and range upwards from eight to twelve pounds, are generally found to pertain to Salmo eriox, the noted bull-trout of the Tweed. The great grey sea-trout of the river Ness, which sometimes reaches the weight of eighteen pounds, we doubt not, also belongs to the species last named. It is rare in the waters of the Tay.

In regard to the seaward migration of salmon fry, Mr Scrope is of opinion that some are continually going down to the salt water in every month of the year, not with their silver scales on, but in the parr state.

"I say, not with their silver scales, because no clear smolt is ever seen in the Tweed during the summer and autumnal months. As the spawning season in the Tweed extends over a period of six months, some of the fry must be necessarily some months older than the others, a circumstance which favours my supposition that they are constantly descending to the sea, and it is only a supposition, as I have no proof of the fact, and have never heard it suggested by any one. But if I should be right, it will clear up some things that cannot well be accounted for in any other mode. For instance, in the month of March 1841, Mr Yarrell informs me that he found a young salmon in the London market, and which he has preserved in spirits, measuring only fifteen inches long, and weighing only fifteen ounces. And again another, the following April, sixteen and a half inches long, weighing twenty-four ounces. Now, one of these appeared two months, and the other a month, before the usual time when the fry congregate. According to the received doctrine, therefore, these animals were two of the migration of the preceding year; and thus it must necessarily follow that they remained in salt water, one ten, and the other eleven months, with an increase of growth so small as to be irreconcilable with the proof we have of the growth of the grilse and salmon during their residence in salt water."—P. 36.

We are not entirely of Mr Scrope's opinion, that some salmon fry are descending to the sea during every month of the year; at least, we do not conceive that this forms a part of their regular rotation. But the nature of the somewhat anomalous individuals alluded to by Mr Yarrell, may be better understood from the following considerations. Although it is an undoubted fact that the great portion of parr descend together to the sea, as smolts, in May, by which time they have entered into their third year, yet it is also certain that a few, owing to some peculiarity in their natural constitution, do not migrate at that time, but continue in the rivers all summer. As these have not obeyed the normal or ordinary law which regulates the movements of their kind, they make irregular migrations to the sea during the winter floods, and ascend the rivers during the spring months, some time before the descent of the two-year-olds. We have killed parr of this description, measuring eight and nine inches, in the rivers in October, and we doubt not these form eventually the small, thin, rather ill-conditioned grilse which are occasionally taken in our rivers during early spring. But it is midsummer before the regularly migrating smolts reappear as grilse. However, certain points in relation to this branch of our subject may still be regarded as "open questions," on which the Cabinet has not made up its mind, and may agree to differ. Mr Scrope is certainly right in his belief, that, whatever be the range of time occupied by the descent of smolts towards the sea, they are not usually seen descending with their silvery coating on except in spring; although our Sutherland correspondent, to whom we have so frequently referred, is not of that opinion. It may be, that those which do not join the general throng, migrate in a more sneaking sort of way during summer. They are non-intrusionists, who have at first refused to sign the terms of the Convocation; but finding themselves eventually rather out of their element, on the wrong side of the cruive dyke, and not wishing to fall as fry into the cook's hands, have sea-ceded some time after the disruption of their General Assembly.

Even those smolts which descend together in April and May, (the chief periods of migration,) do not agree in size. Many are not half the length of others, although all have assumed the silvery coat. "I had, last April," Mr Young informs us in a letter of 3d June 1843, "upwards of fifty of them in a large bucket of water, for the purpose of careful and minute examination of size, &c., when I found a difference of from three and a half to six inches—the smallest having the same silvery coat as the largest. We cannot at all wonder at this difference, as it is a fact that the spawn even of the same fish exhibits a disparity in its fry as soon as hatched, which continues in all the after stages. Although the throng of our smolts descend in April and May, we have smolts descending in March, and as late in the season as August, which lapse of time agrees with the continuance of our spawning season. But in all these months we have an equal proportion (that is, a corresponding mixture) of large and small smolts. I have earnestly searched for smolts in the winter months, year after year, and I can only say that I have never seen one, although I have certainly tried every possible means to find them. I have seen fish spawning through the course of six months, and I have seen smolts descending through the same length of time. Our return of grilses, too, exactly corresponds with this statement. Thus a few descending March smolts give a few ascending May grilses; while our April and May swarms of smolts yield our hordes of grilse in June and July. After July, grilses decrease in numbers till October, in proportion to the falling off of smolts from May to August. At least these are my observations in our northern streams." They are observations of great value, and it is only by gathering together similar collections of facts from various quarters, that we can ultimately attain to a clear and comprehensive knowledge of the whole subject.