SALMON— MARKING FISH. ^ 7f) 



Before passing from the migrations of salmon, it is necessary to observe 

 npou what have been termed " pool-bound " fish,* or those which have been some 

 time in the river, remain in the pools, but refuse to rise to the angler's lure, 

 consequent upon the absence of floods : while, owing to their having been some 

 time from the sea, they are generally of a more or less red or rusty colour. 



Marking fish is of ancient date. Isaak Walton alluded to observations made 

 by tying ribbons on the tails of some numbers of young salmon which were taken 

 subsequently at the same place. The reasons for thus marking fish are various, 

 as for the purpose of tracing their growth or their migrations, or facts as to their 

 breeding, such as whether they do so annually, biennially, or otherwise. And 

 while it is necessary that the marks should be distinct, in order that the fish may 

 be unmistakably recog-nized at any future date, even by common fishermen, f it 

 is also desirable not to occasion any serious injury. It would be better did the 

 skin remain unbroken, as abrasions might be the means by which the spores of 

 the dreaded saprolegnia may obtain admittance ; also external pressure long 

 continued may set up irritation, ulceration, and so induce fungus ; while any 

 markings must not be allowed to interfere with the movements of the fish. 



Cutting part of the fins has been advocated, such as one of the lobes of the 

 tail, or removing part of the bases or lower portion of some of the rays in the 

 back fin : or else employing the dead or adipose fin for this purpose, as dividing it 

 into two, cutting a notch out of it, or even removing it entirely ; but it is difiicult 

 to obtain such a variety in sections of these fins that we could distinguish any 

 particular fish so as to be positive as to the period when it was last marked. 

 Also some forms of incisions, as for extracting the lower portion of rays, may 

 occasionally be seen in fishes captured in the wild state, while removing portions 

 may be due to the attacks of enemies. 



Branding is open to many objections ; and although Buckland suggested a 

 burn from a match on the cheek would be indelible, such is doubtful ; while even 

 were an indelible scar there, its origin would always be open to question. In 

 short, branding, to be efficient, must cause mutilation. 



Cross-cupping kelts has been advised, but cannot be recommended. 



Puncturing a hole in the gill-covers was not foimd to be a success at 

 Stormontfield, as the place rapidly filled up again {Brown, p. 68). 



Elastic bands round the free portion of the tail so far have been a failure. 

 I tried them in 1885, using both elastic bands punched out of a flat sheet, and 

 likewise bands cut from tubing ; but the result was unsatisfactory, the pressure 

 occasioning fungus. On netting a pond at Howietoun in October, 1886, in which 

 several fish had been .so marked, none were found ; and some are known to 

 have died from fungus which these bands evidently caused. One sent to an 

 aqiTarium even lost the whole of its caudal fin, but still lives. Possibly the fish 

 thus marked in the rivers of the United States were not again recaptured, because 

 they had all died. 



It seems to be generally considered that a metallic tag is necessary, having a 

 number stamped upon it, and attached by a wire to one of the fins. J: A silver 

 wire has been placed in the form of a loose ring through the dead fin, but it 

 seems very questionable whether it would not most jjrobably ulcerate through, 

 and so be lost.§ A wire has also been placed round the bases of the first or last 

 few of the dorsal rays. In the United States, the first tag employed was a thin 

 aluminium plate, i x :!■ of an inch, attached to an india-rubber band, which 

 encircled the free portion of the fish's tail : but no fish thiis marked were 

 recaptured. Next an aluminium tag was attached by a platinum wire at the base of 



* See article by Mr. Senior, Red Spinner, Field, September 25th, 1886. 



■(■ It is almost needless to point out that care should be taken that they cannot be imitated for 

 the purpose of obtaining rewards. 



X At Stormontfield, Brown observed that no ringed fish were retaken, so he questioned 

 whether a foreign substance could be inserted into a smolt in fresh water, that would remain for 

 any length of time attached to the fish after it had gone to the sea. 



§ Plated tags, with numbers engraved on them, are employed on the Severn ; but it is very 

 doubtful if they will be a success. The fish is held in the lave net at the side of the boat while 

 the wire is passed through its fin. Zinc labels, of course, would be destroyed by sea water. 



