Essays in Natural History and Agriculture. Garnett Thomas

Чтение книги онлайн.

СКАЧАТЬ May or June; and what you called Pinks, which remained till the following year; and Brambling Smolts, which remained another year. The fishermen here are also of opinion that neither Salmon nor Trout spawn every year. Robinson says that one day lately (the letter is dated December 13th) he caught seven Trouts, six of which were in good season; and he brought me two the other day, one of which contained roe, and the other was in excellent condition." My friend states, in a subsequent communication, that one of the fishermen had told him that he had caught the male Smolt (Par) more abundantly on the Salmon spawning beds than elsewhere, and my friend adds that the opinion there is, that if a female Salmon gets up to the spawning beds, and if no male accompanies her, yet her eggs are fecundated by the male Smolts; and they allege, in support of this opinion, that a female got up one season and spawned, and though no male was seen near her her eggs were prolific. I mention this, although I apprehend it is evidence which the unbeliever will consider inadmissible, for though no male was seen, still there may have been one, or admitting that one did spawn, without being accompanied by a male, yet another, which contrived to bring her mate along with her, may have spawned in the same place the same season; yet, notwithstanding its liability to these objections, I have no doubt myself that if a female were to come alone her eggs would be impregnated by the Par. It is an excellent maxim, that Nature makes no useless provisions; yet, if we admit that Par are young Salmon, for what purpose is the milt if not to impregnate Salmon roe? and if we deny this to be the fact, we must endeavour to show that there are female Par, but in all my examinations, I have never been able to meet with one that contained roe. That the Grilse are Salmon is proved I think sufficiently by the evidence given before the House of Commons. Mr. Wm. Stephens states (see Rep., p. 52) that he has known Grilse kept in a salt-water pond until they became Salmon, and that fry that had been marked came back that year as Grilse, and the year after as Salmon; and Mr. George Hogarth states that he has often seen a Salmon and a Grilse working together on the spawning beds, as two Salmon, or two Grilse; and Mr. Mackenzie states (page 21) that he, in March, 1823, marked a Grilse Kelt with brass wire, and caught it again in March, 1824, a Salmon of seven pounds weight. The testimony of the witnesses from the Ness, the Severn, the Lee, and some other rivers, is too positive and too well supported to admit of any doubt as to the excellent condition of many of the fish ascending those rivers in November, December, and January—a period when they are out of season, and full of spawn generally, and even when many fish are caught in those rivers in the same unseasonable condition. The fact that there are many fish in fine season in those months may be, I think, accounted for, if we admit that Salmon spawn every other year, which I have I think shown to be very probable; but what it is that induces those fish to ascend rivers so many months before the spawning season, I cannot explain. Probably there may be some quality in the waters of these rivers, all the year, which is congenial to the habits of the fish, while the same quality may only be found during part of the year in others; it is certain that the quality of the waters in rivers generally varies very much with the season: thus the water of the Ribble, after a flood in summer, is always of a dark brown colour, being so coloured by the peat moss over which it passes, while in winter no such tinge can be observed; and there may be other differences with which we are unacquainted; however, whether this is the true reason or not, it certainly cannot be that the fish which spawn in October are impelled by their desire to propagate their species to ascend the river the January before; and if this long residence in fresh water were necessary for the proper development of the ova in one river, we might suppose it would be necessary in all; yet this is not the case, as the red fish which ascend the river in November and December have at that time the spawn in them nearly ready for exclusion.

      On one point, about which there is great difference of opinion, viz. whether the fish which are bred in the river generally resort to it again, and whether each river has its own variety of fish, I am not a competent judge, as I am acquainted with too few rivers to pretend to decide. I may, however, just remark that the Hodder, though it is a much smaller river than the Ribble, is always much better stocked with Salmon, Morts, Sprods, Smolts, and Par than is the latter river, which I attribute to the fact that more fish spawn in the river Hodder, which runs for many miles through the Forest of Bowland (the property of the Duke of Buccleuch) and other large estates, and the fish are much better protected there than in the Ribble, where, with one or two exceptions, the properties are very much divided, and few people think it worth their while to trouble themselves on the subject. Dr. Fleming, in his letter to Mr. Kennedy (Appendix to the first Rep., 1825), seems to doubt that Salmon enter rivers for any other purpose than of propagation, but lest I should misrepresent his opinions, I will quote what he has said on the subject:—"In the evidence taken before the Select Committee during the last season of Parliament, and appearing in the report, there are several statements of a somewhat imposing kind, which, as they appear to me to be erroneous and apt to mislead, I shall here take the liberty of opposing." He then enumerates several opinions expressed before the Select Committee, one of which is, that Salmon enter and leave rivers for other purposes than those connected with spawning (see the evidence of Messrs. Little, Halliday, and Johnstone).

      First, "That they enter rivers to rid themselves of sea lice (Monoculus piscinus);" secondly, "That they forsake rivers to save themselves from being exhausted by residence in fresh water, and from having their gills devoured by a maggot (Lernaea salmonea)." The whole history of the Salmon contradicts this hypothesis. Another of these errors is, that it is asserted (Rep., 1824, p. 145), "That Salmon always return to the same river;" this is not probable, when we consider the circumstances in which they are placed during their residence in the sea. On the first of these opinions, I am not a competent judge; but I think that the fact that Salmon enter rivers nine or ten months before they are ready to spawn, is of itself sufficient to show that there are other reasons for their entering rivers than those connected with propagation. With respect to the second, I believe that after Salmon have once entered rivers, at least when they have ascended into the upper parts of them, they never offer to descend again until they have spawned. On the third opinion I would remark, that although I do not think that Salmon always come to the same river in which they were bred, yet I think they will do so if they can; and I think that the fact which I have mentioned of the Hodder, a smaller and a tributary stream to the Ribble, containing many more Salmon, as well as more Morts and Sprods, countenances this supposition, for why should the larger number of fish ascend the smaller river except for such a reason?

      I am of opinion that Salmon do not grow so fast in the sea as is generally supposed. It is here generally believed that the Smolts, which go down in the spring, come up again in the August or September following, five or six pounds in weight; and George Little, Esq., in his evidence states that as his opinion, but he does not give any other reason for it than this: "That the Grilse that ascend the river in June weigh one and a half or two pounds, and that those which come in September weigh five or six pounds,"—but opposed to this supposition is the evidence of Mr. Mackenzie, before referred to (second Parl. Report, p. 21), who states that he caught in March a Grilse Kelt which weighed three and a half pounds, that he marked it with a brass wire, and let it go, and that in the March following he caught it again a Salmon of seven pounds weight. Now a fish which weighed three and a half pounds as a Kelt, would weigh five pounds or six pounds when in high condition the summer before, and if this were so, which I believe all persons who are acquainted with Salmon will admit, the fish would have gained only one pound or two pounds in fifteen or eighteen months. Besides, if Salmon grew as fast as is stated and believed by many persons, the breeds of different years would vary very much in weight, whereas it is known to everybody that we have them of all sizes, from five pounds to forty pounds; and it is contrary to analogy to suppose that a fish which is two or three years in arriving at the weight of as many ounces, should in two or three months acquire as many pounds. There are, however, two or three things about which all persons agree in opinion—one of these is: that the breed of Salmon is decreasing every year, and that the great cause of this decrease is the want of protection, and a consequent destruction in the spawning season. The complaint on this head is universal from north to south; from the Shannon to the Tweed, the cry is—"Protect the breeding fish, or we shall very soon have none to protect." And yet, although the destruction of the spawning fish, and the destruction of the fry in the Spring, are the chief reasons for this alarming falling off, no one seems able to devise a remedy; no one seems inclined to make the necessary sacrifices for so desirable СКАЧАТЬ