Íslenskar landbúnaðarrannsóknir - 01.09.1978, Blaðsíða 114

112 fSLENZKAR LANDBÚNAÐARRANNSÓKNIR
SUMMARY
In these experiments, hatchery smolts
were planted into a barren stream and
into a productive salmon stream, using
two release methods: a direct plant versus
a plant from a release pond. The survival
turned out to be 2-4 times better using a
release pond.
I’he survival of wild smolts was very
high, estimated at 25.8% including es-
capement. The survival of the hatchery
smolts was much lower (7-8%) but does,
however, contribute significantly to the
total run to the river.
The releases of hatchery smolts into
barren streams have a great potential
which should be further explored. The
releases of smolts into productive streams
can also by of importance provided that
there is a proportional increase in fishing
pressure.
ÍSLENZKT YFIRLIT
Notkun örmerkja við rannsóknir á mismunandi
aðferðum við sleppingar gönguseiða í Elliðaám
og Artúnsá
eftir
ÁRNA ÍSAKSSON
Veiðimálastofnunin, Reykjavík
TonyJ. Rasch
Washington Department of Fisheries,
Olympia
Og
Patrich Poe
College of Fisheries,
University of Washington
The egg-to-smolt survival was calcu-
lated at Ellidaár and found to be 0.4%.
Straying of the hatchery smolts to
Kollafjördur was very significant at Ár-
túnsá but of minor importance at Ellidaár.
Low mineral content and absence of sal-
mon at Ártúnsá is the most logical expla-
nation.
The total run of salmon to Ellidaár in
1976 was close to 4,000 salmon. About
1,690 salmon were caught - about 42%
exploitation rate.
Weight differences at return between
wild and hatchery smolts could be
explained by mean length at release.
There was a significant difference in the
distance traveled by the wild and hatchery
smolts at Ellidaár, the wild smolts going
further upstream.
örmerktum gönguseiðum var sleppt í
laxveiðiá og laxlausa á með tvennskonar
sleppingu. Annarsvegar voru seiðin að-
löguð ánni í sleppitjörn á árbakkanum í
2-3 vikur. Hinsvegar var þeim sleppt
beint í ána eftir flutning úr eldisstöðinni.
Náttúruleg sjógönguseiði voru einnig
veidd í gildrur í laxveiðiánni og örmerkt til
samanburðar við eldisseiðin.
Það kom í ljós að sleppitjörnin marg-
faldaði endurheimtu úr sjó samanborið
við beina sleppingu. Eldisseiðin, sern sett
voru í laxlausu ána, villtust verulega í eld-
isstöðina, þar sem þau höfðu alizt upp,