Translation 3025

FISHERIES AND MARINE SERVICE
Arc, h ive
Translation Series No. 3025
The development of a device for counting fish fry
by A.S. Muravlev .
Original title: Razrabotka ustroistva dlya uchota molodi ryb
From:
Trudy VsesoyuznogoNauchno7IssledoVaterskogo Instituta MorskogO
Rybnogo Khozyaiètva i Okeanografii (VNIRO) (Proceedings of the •
All7Union Research Institute of Marine Fisheries and Océanography).,
88 : 9699, 1972 -
Transiated -by the Triinsiation-BUreau(NDe
Multilingue Services DiVision Departnent•of the SecretaryoUState of Canada
Department of the.Envitonnent
Fisheries and Marini Service
Biological Station,-Nanaimo, B.C. Arètic Biological 'Station, Ste. Anne de Bellevue,
Biological Station, St. John's,
.
.
' 1974
4 pages typescript
-
••••• '
s
,
•
,
DEPARTMENT OF THE SECRETARY OF STATE
TRANSLATION BUREAU
MULTILINGUAL SERVICES
SECRÉTARIAT D'ÉTAT
ge
lek
ee
BUREAU DES TRADUCTIONS
ts
DIVISION DES SERVICES
CANADA
DIVISION
MULTILINGUES
TRANSLATED FROM - TRADUCTION DE
Fy4/1.
INTO - EN
Russian
s
3bc2
English
AUTHOR - AUTEUR
e.V
A.S. MuravlyervTITLE IN ENGLISH - TITRE ANGLAIS
The development of a deviCe for counting fish fry
TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS)
TITRE EN LANGUE ÉTRANGÉRE (TRANSCRIRE EN CARACTLRES ROMAINS)
Razrabotka ustroistva dlya uchota molodi ryb
REFERENCE IN FOREIGN LANGUAGE (NAME OF BOOK OR PUBLICATION) IN FULL. TRANSLITERATE ‘FOREIGN CHARACTERS.
RÉFÉRENCE EN LANGUE ÉTRANGÉRE (NOM DU LIVRE OU PUBLICATION), AU COMPLET, TRANSCRIRE EN CARACTÉRES ROMAINS.
Trudy VNIRO
REFERENCE IN ENGLISH - RÉFÉRENCE EN ANGLAIS
Trudy of the All-Union Research Institute of Marine Fisheries
and Orenography
PAGE NUMBERS IN ORIGINAL
PUBLISHER - ÉDITEUR
DATE OF PUBLICATION
DATE DE PUBLICATION
NUMÉROS DES PAGES DANS
L'ORI GI NAL
not available
YEAR
ANNÉE
PLACE OF PUBLICATION
LIEU DE PUBLICATION
USSR
REQUESTING DEPARTMENT
MINISTRE -CLIENT
Environment
BRANCH OR DIVISION
DIRECTION OU DIVISION
PERSON REQUESTING
DEMANDÉ PAR
Fisheries Service
YOUR NUME3ER
05.2 00-1 0-6 (R E V. 2/68)
7530-21-029-6333
96-99
ISSUE NO.
NUMÉRO
NUMBER OF TYPED PAGES
NOMBRE DE PAGES
DACTYLOGRAPHIÉES
..111
4
TRANSLATION BUREAU NO.
NOTRE DOSSIER N°
TRANSLATOR (INITIALS)
TRADUCTEUR (INITIALES)
784560
N. De.
J.G. MrDonald
VOTRE DOSSIER N°
DATE OF REQUEST
DATE DE LA DEMANDE
1972
VOLUME
April 9 9 1974
Vor
TRAD UCT; r-!t NON I.:13'PS
rkrikn see!vrrtent
et
•
DEPARTMENT OF THE SECRETARY OF STATE
SECRÉTARIAT D'ÉTAT
TRANSLATION BUREAU
BUREAU DES TRADUCTIONS
MULTILINGUAL SERVICES
DIVISION DES SERVICES
DIVISION
MULTILINGUES
DEPARTMENT
MINISTE' RE
CLIENT S NO.
NQ DU CLIENT
Environment
DI VISI ON/BRANCH
CITY
DIVISION/DIRECTION
VILLE
Fisheries Service
BUREAU NO.
LANGUAGE
TRANSLATOR (INITIALS)
NO DU BUREAU
LANGUE
TRADUCTEUR (INITIALES)
_.
.
NAY
N. De.
Russian
784560
Nanaimo, B.C.
1 5 19 74
LINED:TED TRA!,1:3LATI3N
inforrin'ic:n
TRADUCTION
REVISE-
Trudy VNIRO, 1972, vol. 88, pp. 96-99
Jnkereation se.u!e.nici-21-
The development of a device for counting fish try
etA,
by A.S. Muravlyeie (KaspNIRKh)
The stocks of valuable species of fishes are replenished by means
of artificial breeding at fish hatcheries.
The output of each hatchery
is estimated in millions of fry a year. At most of the hatcheries, the
young fish are counted individually, i.e. each fish is removed from the
water by hand, which can cause injury. Repeated attempts have been
made to mechanize the laborious process of counting young fish reared
in ponds.
Several of the mechanized devices being used at present are
based on the volume, weight and individual counting methods.
When using the volume method, the young fish are placed in a
container or chamber having a definite volume which is divided by the
average volume of one fry; by the weight method, the young fish are
removed from the water and weighed.
The obtained weight is divided by
the average weight of one fry taken from the control batch. Devices
based on these two methods have not proved practical for the reason that
the fish are sometimes injured; other aquatic organisms get into the
counting chamber too with the fry, which results in a very inaccurate
* The numbers in the right-hand margin are the pages
of the Russian text - translator.
SOS-200-10-31
(96)*
2
reading; the fry have to be removed from the water for at least a short
time; and some of the operations have to be carried out by hand.
The most efficient and accurate method is counting item by item,
as it completely .eliminates subjective errors. Besides,
the fry do not
have to be taken out of the water, which increases the survival rate.
At the present time, there are mechanical and photoelectronic
devices for counting large fish individually, as well as devices for
counting larvae and fry in laboratory conditions.
However, these are
not suited for counting the masses of young fish released from breeding
ponds.
The mechanization laboratory of KaspNIRKh has worked out a line
diagram of a device for counting each young sturgeon as masses of them
are released from the ponds; this device consists of photoelectric sensors,
electronic amplifiers and electromagnetic counters (fig. 1).
Fig. 1.
Line diagram of the device.
The photoelectric sensors are made up of a (PC-K1 photoconductor
and a 25-watt electric lamp which are installed in pressurized heads with
piano-convex lenses. During operation, the heads with photoconductor
and lamp are immersed in water. The device registers the current impulses which first arise in the photoconductor circuit when the body of
a fry shutters the light flux emitted by the lamp through the water layer.
3
However, these impulses are too weak to set the electromagnetic counter
working, and so they are amplified on a secondary device.
The device was tested in the laboratory. The photoheads (1) and
lamps (2) were placed in a tank (3) filled with water (fig. 2a), and tin
plate models of fry fixed on a bearer as well as Formalin-treated fry
of the beluga and sturgeon were moved between them at a speed of 0.2-0.4 m/sec.
:_,
Powex- s..,u.,-C-eR L1C%riUu.f/61JC!-f
t7Nlï^CtH41 A
6
EY
e,,,«_eFig. 2.
C_
Arrangement of the photosensors:
a) in the tank; b and c) on a panel in staggered row
and in one line.
The photosensors were arranged on a metal panel in staggered rows
with a distance of 20 mm between theircentres. The transparency of the
water in the outlet channel as the young fish were being released from
the ponds changed from 16 to 40 cm, and in the tank from 7 to 70 cm
when silt was added to the water.
As the experiments showed, the photoconductor is illuminated
very little when the transparency of the water is low (7-10 cm). The
light flux being emitted by the lamp falls on the particles suspended
in the water and disperses, striking not only the photoconductor at which
(98)
4
it is directed, but also the other ones around it. As a result, a
continuous illuminated field is formed.
At a distance of 5-7 cm between
the photohead and lamp, the device reacts poorly to the objects being
counted (a significant time lag and random response was observed).
At
water transparency over 15 cm, the dispersed light has a smaller effect.
At a distance of 10 cm between the photohead and lamp and the complete
covering up of the light flux by the object being counted, the device
operates steadily and responds well to the passing by of each model or
fry, and the time lag is considerably reduced. However, if the object .
covers only one-third or one-half of the photoconductor lens, the time
lag will increase and omissions will occur.
In order to eliminate these shortcomings, the photosensors were
arranged in one line with angles separating the photoconductors from each other (fig. 2c); these angles directed the passing fry right over the
lens of the photoconductor.
In this case, the effect of the dispersed
light from the nearby lamps was eliminated.
As the experiments have
shown, all the objects (models and fry) passing through the photosensors
cover the entire area or 2/3 of the photohead lens, regardless of their
size. At water transparency over 16 cm and a 10-12 cm distance between
the photohead and lamp, the device operated with precision (without
setbacks or omissions). •
It has been established that the device for counting the fry of
sturgeons individually is efficient if the transparency of the water
at the place it has been installed is not less than 16 cm.