Íslenskar landbúnaðarrannsóknir - 01.09.1978, Page 42

ÍSL. LANDBÚN.
j. agr. res. icel. 1978 10,2: 40-46
Fishery statistics
Maríanna Alexandersdóttir, Geir R. Jóhannesson,
Institute of Freshwater Fisheries, Reykjavík.
Phillip R. Mundy,
College of Fisheries, University of Washington, Seattle.
and
Einar Hannesson
Institute of Freshwater Fisheries, Reykjavík.
ABSTRACT
A computer program was developed for handling catch and eífort data for Icelandic salmon streams. The
program is written in FORTRAN IV for processing on IBM 360/30. The output contains all statistics used
today, but arrangements are made for expansion such as to provide district summaries, or for incorporation
into an international file for catch statistics of the Atlantic salmon.
INTRODUCTION
A first, and simple way of monitoring
changes in abundance of the stock of sal-
mon in a river is to record the catches.
Under assumptions of constancy in eífort
and catchability of the gear, the catch
gives a relative measure of the total run,
which can then form a basis for manage-
ment of the fishery.
The next step is to use catch and ex-
pended effort for estimation of total run,
whereby the fishery can be regulated so as
to provide the necessary allocation of the
run between spawning stock and harvest.
The stage is also set for relating success of
spawning to environmental factors.
The salmon management program,
„SALMAN,“ described here was de-
signed to process catch data recorded in
the logbook (Veiðibók) maintained by the
owner of a stream or a representative
Fisheries Association. In the summer of
1974 P. R. Mundy wrote an initial prog-
ram. Later G. R. Johannesson prepared
the present program for the IBM 1620
machine. This program was eventually
modified for an IBM 360/30 by Maríanna
Alexandersdóttir.
DEVELOPMENT OF FISHERY
STATISTICS
The early records were kept for revenue
purposes. From 1896 through 1911 the
catches were published in Lands-
hagskýrslur and from 1912 to 1946 in
Hagskýrslur íslands (Friðriksson 1940).