April 22, 1893] 
THE EI8HING GAZETTE 
291 
EXPERIMENTS IN 
MAEKING SALMON and SEA-TROUT 
ON WEST COAST OF NORWAY. 
The following is a translation of a lecture 
recently delivered by the Norwegian Fishery 
Inspector, Herr A. Landmark, at Gothenburg, in 
regard to experiments in marking salmon and sea- 
trout, undertaken of late years in Norway, which 
contains much interesting matter:— 
“The investigations and experiments which 
have been set on foot during a long series of years 
in order to unravel the different questions con¬ 
cerning the natural history and habits of the 
salmon, have in no inconsiderable degree increased 
our knowledge on this subject. But when one 
investigates the matter more closely, we find 
that our knowledge of the salmon’s natural history 
is still very imperfect, and it even seems that the 
more one learns the more there remains to learn. 
Many of these unexplained questions have great 
practical importance. 
“In Norway we have of late years made a 
number of experiments, through which, I think, 
that some of these gaps in our knowledge are in 
a fair way to be filled up. Since the years 1883 
and 1884 we have made experiments in marking 
salmon and sea-trout; in 1883 the Storthing voted 
funds for this; since then about 4000 salmon and 
2000 sea-trout have been marked, and these 
experiments are still being carried on. In this 
way we have obtained a deal of enlightenment in 
regard to the salmon’s wanderings, growth, &c., 
certainly not yet sufficiently comprehensive, and, 
therefore, not such that we can draw from them 
generally fully reliable conclusions; but I consider 
myself justified in making use of the present 
opportunity to communicate the results which 
we would now seem to have obtained. 
“ In various other places, of course, experiments 
in the marking of salmon have been made, but, as 
far as I have been able to ascertain, these experi¬ 
ments have been imperfect, inasmuch as only a 
very small proportion of the fish marked have 
been found again. There was, therefore, no satis¬ 
factory precedent to follow, and I have, therefore, 
been obliged to feel my way, and so have used 
marks of a different description, and attached 
them to different parts of the fish, &c. It must 
be confessed, however, that hitherto I have been 
unable to ascertain the best manner in which to 
attach the mark, although I think that the latest 
form of marking and its results are very satis¬ 
factory. 
“ For purposes of identification we have used 
small metal plates, made fast to one of the fish’s 
fins. Each plate is stamped with a number in 
progressive series, so that every fish furnished 
with one, if taken again afterwards, can be dis¬ 
tinguished from all the others, whether marked 
at the same or another time. 
“ At the time of marking, the fish is weighed 
and its measurement taken, and when possible its 
sex also is noted in a special minute. At first 
platina plates were used, which were made fast 
by a wire of the same metal to the fish’s adipose 
fin, or in the case of very small fish to the upper 
half of the tail fin. 
“ On account of the expensiveness of the metal, 
and in order to attract as little as possible the 
notice of beasts and fish of prey to the fish thus 
marked, the plates and wire were made very 
small and thin; but a year’s experience proved 
that the wire and the plates in consequence were 
wanting in the necessary strength, as several fish 
were recaptured, which, it was apparent, had 
bean marked, but which had lost the plate, or 
both it and the wire. Trial was therefore made 
later with silver plates and silver wire of very 
high f(uality, and as it would seem that these, at 
any rate for a number of years, completely resist 
the influence of salt water, I have of late taken to 
using them, especially as they are much cheaper 
than platina, although of larger size. The shape 
of the plates, and the manner in which they are 
attached to the fish, have undergone alteration. 
Up to 1888, plates were used of an oblong form, 
in which one end of the metal thread was fastened. 
The free end of the thread was passed through 
the fish’s fin, and afterwards twisted fast to the 
end attached to the plate. 'I he length of the 
plates varied from 9 to 12mm., the width from 
4 to bmm. The thickness of the platina plates 
was sometimes O.Orimm., sometimes 0 1mm., whilst 
the silver ones had a thickness of 0.2 mm. to 0.4mm. 
The platina wire used for securing the plate was 
from 0.15mm. to 0.25mm. thick, while occasionally 
this was doubled. The thickness of the silver 
wire was 0.35mm. Although the edges of the 
plates were rounded off, and the plates lay as 
close as possible to the fin, they would seem to 
have been too light to remain fast during the 
fish’s movements under all circumstances, 
especially when taken in a net. In 1888, there¬ 
fore, I determined to use plates of a considerably 
different make, together with a different method 
of attachment from that employed in connection 
with the older plates. The new plates (series F) 
are shaped thus 1“*^. The horizontal line indi¬ 
cates a plate 10mm. long, and 4mm. broad, on 
which the number is stamped; the two bent 
down claws taper off rapidly from the plate, and 
end in a sharp point. 
“ The plate is made fast to the fish in this way, 
that the two claws are thrust through the fish’s 
back fin, in the hindmost part, and as near the 
base as possible, after which both points are bent 
inwards towards one another, and jammed into 
the fin. 
“ By this means the plate in its entirety is 
pressed quite fast into the fin, and offers practi¬ 
cally no resistance to net or other object with 
which the fish comes in contact. 
“ That the plate as now adapted is fastened to 
the dorsal instead of to the adipose or tail fin, is 
certainly an improvement also, as the dorsal fin 
being placed in the middle of the fish does not 
move so much as the two other fins named. 
“ The new plates (which are made of very fine 
silver) are therefore undoubtedly more suitable 
for the purpose than those formerly in use. 
“But of these also it wmuld seem that many have 
been lost from the causes that formerly applied, 
namely, that the plates were too small and the 
silver used too thin. Hereafter, therefore, larger 
and thicker plates will be used. 
“ The places where these experiments have been 
made are practically all situated in the south¬ 
western part of the country. The marking has 
been carried out especially on the following 
rivers—the Suldal river in Ryfylke, the Figgen 
river in Jaederen (both in Stavanger Amt), the 
Sireaaen (between Eckersund and Flekkefjord), 
the Kvina (between Flekkefjord and Farsund), 
and the Topdal river (at Christiansand). At 
other than these places few fish have been 
marked. The marking has been carried out almost 
invariably during or about the spawning time, late 
in autumn or in the early part of the winter. In 
order to draw attention as much as possible to 
the marked fish which might be recaptured later, 
and to have the required information respecting 
them forwarded on to me, I have twice had 
printed a large number of circulars, which have 
been distributed among fishermen by Lensmaend 
and salmon buyers, especially in the southern and 
western districts, and wherein I have invited 
fishermen as well as buyers to examine all fish 
caught or bought by them for marks, and 
promising a reward, in the first place of 2 kroners 
and afterwards 3 kroners, for each plate found 
and sent to me, accompanied by reliable evidence 
as to the time and place of capture, and the fish’s 
length and weight. 
“ Although this reward appears to me quite 
sufficient to indemnify those concerned for any 
trouble they may be put to, and the whole plan is 
arranged in the interests of the fishery owners 
themselves, I have reason to believe that many 
marks have been overlooked, and that with a 
mistaken conception of the intention, fishermen 
have frequently omitted to send information 
regarding marked fish which they have captured. 
“ After these explanations in regard to the 
methods for marking fish now in use, I will briefly 
relate the results obtained up till now of these 
expei’iments in marking. 
“ Apart from a number of fish which have been 
retaken in the same river in which they have been 
released, before they left it, there are particulars 
of over fifty-three salmon in all whose place of 
release and recapture are accurately known. 
“The places of release were as follows:—The 
Topdal river, two ; Sireaaen, fifteen ; the Figgen 
river, one; the Suldal, thirty-five. A closer con¬ 
sideration of the different places where these fish 
were recaptured offers many points of interest. 
Many will doubtless be astonished to learn at 
what a great distance from the place of release 
the fish have in many cases been recaptured, and 
how extensive the fish’s wanderings along our 
coasts must therefore be. On the other hand, the 
greater number of fish have been retaken in the 
same river where they were released, or in the 
sea at a short distance from the mouth. The 
details are as follows :—The salmon marked in the 
Topdal were both retaken in that river or at its 
mouth ; those belonging to the Figgen on the 
other hand were taken in the sea at Algeroen in 
the Fjelds Prestegjeld, near Bergen, or at a dis¬ 
tance of about 18i) kilometres from the Figgen 
river. The salmon belonging to Sireaaen would 
seem to be still greater wanderers; of the fifteen 
fish marked there and afterwards recaptured, 
seven were taken in the river itself, and two in 
the sea at no great distance from the mouth ; but 
one was retaken in the Kvina, a river which has 
its exit about thirty-five kilometres east from 
Sireaaen, and five in the sea at considerable dis¬ 
tances from the river’s mouth—one in Haa Fres- 
tegjeld in Jaederen (65 kilom.), one at Sandeid in 
Ryfylke (about 180 kilom.), at Balestrand in the 
Sogne Fjord (about 425 kilom.), one at Vefring, 
in the Sondfjord (about 400 kilom.), and finally 
one at the entrance to the Trondhjem Fjord 
(about 800 kilom.). The Suldal fish, again, would 
seem to be more stay-at-home ; of the thirty-live 
salmon marked there and recaptured, nineteen 
were taken in the river itself, twelve in the fjords 
of inner Ryfylke, within a distance of 45 kilom. 
at most of the mouth of the river, and only four 
were recaptured at any great distance, namely, 
two in the neighbourhood of Haugesund (about 
90 kilom.), one at Hisken in Finaas (about 115 
kilom.), and one at Mogster (about 150 kilom.). 
A comparison on this basis between the places of 
recapture of the salmon belonging to the Sireaaen 
and the Suldal, would seem to show a distinctly 
more marked tendency on the part of the former 
to wander far along the coast than the latter. 
And as regards the Sireaaen- salmon, there 
appears to be reason to believe that many of the 
fish retaken would never in any case have returned 
to their native river. This may perhaps be 
accounted for by the circumstance that the water 
of the Sireaaen has a very low temperature in 
spring and early summer compared with all the 
other rivers on that side of the country, due 
partly to the high elevation at which it flows, and 
partly to the large and very deep lakes on its 
lower course, Lundevand and Sirdalsvand, which 
in winter are filled with nearly ice-cold water that 
lasts well into the summer. As temperature has 
a very important effect on the salmon’s wanderings 
it would seem that the great difference which 
exists in spring and early summer between the 
water of the Sireaaen and that of the sea into 
which it flows, possibly causes a large proportion 
of the fish belonging to that river to seek others 
with a temperature more in accordance with their 
tastes. 
*• Further it should be remarked with regard 
tothefishnot retaken in the same river or its imme¬ 
diate neighbourhood, that with one exception, the 
Sireaaen salmon recaptured in the [Kvina, all 
such places of recapture lay to the north of the 
river concerned. This is no doubt because the 
current along the west coast of Norway generally 
sets to the north, and the salmon, as is well-known, 
are in the habit of going with not against the 
stream in the sea during the fishing season or the 
summer months. It makes it more probable 
therefore that those fish taken so far from their 
native river would not in any case return thereto. 
“ If this assumiition is right, there is reason 
also to think that on the whole a comparatively 
important number of the salmon which belong 
to the rivers of the south-west and west coasts 
of Norway, gradually proceed northwards, and 
ultimately ascend rivers situated further north, 
and that thus the northerly districts of the 
country are more deeply interested in the jiroper 
management of the fisheries in the more southerly 
ones, than the latter are in the former. 
“ It appears to me not unlikely that herein lies 
an important reason why the fisheries in the 
districts round the neighbourhood of the Trond¬ 
hjem Fjord have remained so good in spite of the 
extraordinarily large number of bag-nets which 
have for years been in use there. At any rate, 
the not inconsiderable number of fish recaptured 
so far from their native rivers shows that the 
fisheries of a district are dependent not only upon 
the manner in which they themselves and the 
