Íslenskar landbúnaðarrannsóknir - 01.09.1978, Page 158

ISL. LANDBÚN.
j. agr. res. icel. 1978 10,2: 156-174
Salmon management and ocean ranching
in Iceland
Ole A. Mathisen
College of Fisheries, University of Washington,
Seattle, Washington
and
Thor Gudjónsson
Institute of Freshwater Fisheries,
Reykjavík
ABSTRACT
Thc salmon ílshcry in Iceland is prcdominantly a sportsfishery. As such, the prime task ofmanagement is
not to maximize the yicld, as in olher ilsheries, bul to achieve the greatest satisfaclion of the angling public.
Thereforc, the spawning population niust bc in excess of the level indicated by a spawner-recruit curve.
The entry pattern of the Atlantic salmon in Iceland is very stable and can be described by a cumulative
catch curve of sigmoid form. The run size can be estimated from the catch per unit of effort once the
catch-ability and vulnerability coefilcients have been ascertained. This necessitates independent counts of
the salmon stock by special counting units in some streams for calibration of catch per unit of effort by
different classes of fishermen and equipment. But since in-season management decisions are difilcult to
achieve, with most of the fishing licenses sold in advance of thc season, the need f'or immediate stock
assessment is less critical than elsewhere where maximum catch is the targel.
Improved fishing can be achieved by releases of smolts in the naturally producingstreams, or in previously
barren streams. But the greatest expansion is seen in ocean ranching when the products are in addition to
meat also eyed eggs orjuvenile salmon and smolts. The natural production basis is the ntixing ofcold and
warm current systems which create highly productive frontal systems. The circulation time in the gyres,
both on the southwestern side and on the northeastern part of Iceland, correspond well to an ocean
residence of predominantly one year or to a smaller degree a 2-year ocean stay.
Economic constraints in form of investment capital, price structure and extent of export markets are the
constraints limiting production today, rather than the capacity of the ocean nursery grounds.
INTRODUCTION
Contrary to the conditions in many other
nations oí' the world, the salmon streams
of Iceland still remain in their pristine
stage. Pollution is nonexistent or minor
compared with conditions elsewhere. The
insular positon of Iceland and the nature
of the surrounding ocean current systems
effectively, although not perfectly, isolate