Essays in Natural History and Agriculture. Garnett Thomas

Чтение книги онлайн.

СКАЧАТЬ small flies which the anglers use in that river—they were then a little larger than Minnows. In the spring of 1818 there were blue Smolts, or what are generally known as Salmon fry, which went down to the sea in the May of that year; but these were only part of the brood, the females only, the males remaining all that summer, being at the period when the females went down very much smaller than they, and what was called at the Wharfe Grey Smolt and Pinks, or Par elsewhere.

      I have shown that there were two migrations from the spawn of 1816; but this was not all—there still remained a few Smolts through the summer of 1819, which by that time were from four to six ounces in weight, and which are known by the anglers there as Brambling Smolts. The blue marks on their sides are very distinct, and the fish is a perfect Smolt, except that it is considerably larger. It is quite different from the Whitling, or Sprod, which is not known in the Wharfe, at least not in the upper parts of that river, whilst the Brambling is never seen in the Ribble. [1]

      The Brambling is a beautiful fish, and it rises very freely both at the May fly and the artificial fly through the summer; it is occasionally caught by anglers with the worm on the Salmon spawning beds in the autumn, with the milt perfectly developed, and in a fluid state. Although this fish is not found in the Ribble, so far as my observations and inquiries have gone, I believe that it is found in the Tweed, and perhaps also in other rivers running into the German Ocean; for a letter addressed to Mr. Kennedy, who was chairman of the select committee appointed to investigate this subject, by a Mr. George Houy, states that the Smolts are sometimes found there ten inches long, which he attributes to their not being able to get down at the proper period for want of a flood in the river. But I know that in the Ribble Smolts will go down to the sea without there being a flood at all, if that does not come within ten days or a fortnight of the time at which they usually descend to the sea. I also know that Brambling are found in the Wharfe, in years where there has been no deficiency in that respect; yet why they should be common in that river, when they are never met with in the Ribble, which has ten times as many Salmon and Smolts in it, I am unable to comprehend.

      It is my opinion that the ova of the Salmon are not hatched before March or April. Two anglers, who were in April wading in the river Wharfe, came upon a spawning bed, which they had the curiosity to examine; they found a number of ova, in which they could see the young fry already alive, and one of them took these eggs home with him. By regularly and frequently supplying them with fresh water, he succeeded in hatching them, and kept some of the young fishes alive for some time; but they died in consequence of neglect, and were even then very diminutive. The opinion generally received in Scotland seems to be, if I may judge from the evidence given before the House of Commons, that the Smolts go down to the sea in the spring after they are spawned, and that they return in the summer and autumn of the same year as Grilse. When they return, and what size they are on their first visit, I have hitherto been unable to ascertain; but I think I have succeeded in proving that they do not go to the sea so soon as is generally believed, nor do any of the witnesses give their reasons for thinking that they do. I should very much like to learn what evidence they have to offer in behalf of this opinion.

      I remember seeing an article in the "Scotsman," perhaps about twelve months ago, in which it was stated that Dr. Knox had made some important discoveries in the natural history of the Salmon and Herring, both in their food and propagation, and, if I recollect aright, it stated that he had ascertained that the eggs remained several months in the gravel, and that then, in a few days or weeks after, they (i.e. the fish hatched from them) were so much grown as to go down to the sea; but none of the data which enabled him to arrive at this conclusion were given, and since then I have heard nothing about the matter. As it is so long since I read this article, I may have quoted it incorrectly, but I believe its substance was what I have stated.

      The only conclusive evidence I can find about the hatching of Salmon fry is that of Mr. George Hogarth (second Parl. Report, p. 92), and his account agrees with my own: he states that he took Salmon spawn from the spawning beds, and by keeping it freely supplied with fresh water, he succeeded in hatching some of the eggs; he gives drawings of the appearance of the fry in three or four different stages, from the egg to the age of eight days (see Appendix to second Parl. Report), that the young fry, by keeping them well supplied with fresh water, were very lively and vigorous for three weeks, but that they after this time appeared to grow languid and uneasy, and as they would eat nothing they died when one inch long. Unfortunately he does not state at what time of the year they were hatched, but if this were in March or April, which I see no reason to doubt, it is sufficient to prove that they would not reach the size that Smolts are when they leave the river for the sea; for supposing them to be hatched the last week in March, and that they lived a month, this would bring us to the time when they are about to migrate, at which time they average more than six inches long; many of them are eight inches, and at this period they are fond of feeding upon worms, flies, maggots, and caddis worms, as is known to every schoolboy living on the banks of a river frequented by Salmon. It is also my opinion that neither Salmon nor Trout spawn every year, [2] for Salmon ascend the river as early as January, in the highest condition, with roe in them no bigger than mustard seed: these could not have spawned that season, as the Kelts, particularly the females, do not return to the sea until March or April, [3] and at that time they are in very bad condition, and do not appear to have a particle of spawn in them; and in the evidence of Mr. Mackenzie (see Parl. Rep., p. 21), we have an account of a Grilse Kelt which was caught and marked in March, 1823, and was again caught as a Salmon on its return to the river in March, 1824. In this case the fish had evidently required a residence of twelve months in the sea before it was in a condition to visit the river a second time, and in the Wharfe it is the constant practice of the angler to catch Trout through the winter with very minute roe in them, and in high condition with the worm and Salmon roe, and also with night lines. In fact, one of the fishermen has frequently remarked to me that he occasionally caught dishes of Trout with the fly in January, and in finer condition, than he has found them in April, which he accounted for by saying that the spawned fish (Kelts) of that season had not begun to rise freely at the fly at the former period, but they had at the latter, so that his pannier contained as many Kelts as fresh fish. Another reason has just occurred to me: it is, that in January the spawned fish will still be in the small brooks in which they are so fond of breeding, and of course the bulk of the fish remaining in the river at that time would be fish in good season.

      As it is some years since I acquired this information, or at least a part of it, I felt afraid of giving it incorrectly; and I therefore addressed a letter to a friend living on the banks of the Wharfe, requesting him to send me all the information in his possession on this subject, that derived from his own observations, as well as that collected from others. He has since the above was written sent me the following reply:—"I have seen Robinson (one of the best anglers and fly makers between Cornwall and Caithness), and have had some conversation with him on the subject of Salmon, &c. He is of opinion that the spawn of the Salmon remains five months in the gravel before hatching; he examined the spawn in April, and found the young fry alive in the eggs, and Ingham, another angler, took some home and kept one of the Smolts two or three months. I have subsequently seen Ingham, and he has given me the same account. All the fishermen here are of opinion that the female Smolts remain one year, and the males two years, before they go down to the sea. The Bramblings are supposed to be Smolts which remain a year longer than the usual time; they are few in number, and are generally taken with the May fly. I have no doubt that the above opinions are correct, for we have now three distinct sizes of Smolts in the river exclusive of Bramblings, the largest of which are nearly four ounces in weight, and are all males, as they contain milt in October and November. The next are the females of the present year: I have had one since the receipt of your letter, which weighed half an ounce and measured five inches in length; this was a real blue Smolt; the third are the males of the same age, and are much smaller; these are occasionally taken with the worm, and will rise at the fly all the next summer."

      "We were for several years, but I do not know the dates, entirely without Salmon, and of course without Smolts; and we invariably found that the Smolts made their appearance the year after the Salmon, but were very small till the second year, when we had what we call blue Smolts, which disappeared СКАЧАТЬ