translation - 3131dfo-mpo.gc.ca/library/111236.pdf · 2012-03-27 · r fisheries and marine service...
TRANSCRIPT
r
FISHERIES AND MARINE SERVICE
Translation Saries No. 3 13I !ARCHIVES
Iceland scallop, Chiamys islandica (0,F. Muller), at Spitsbergen and Bear Island.- Investigation in 1973
by K.F. Wiborg, k.Hansen, and H.E. Olsen'
Original title: Haneskjell (Chlamys ialandica Muller) ved Spitsbergen og Bjç4rny6ya Underskelser i 1973
From: Fiskets Gang (FisberiesMigration), 60(11) : 209-217, 1974
• Translated by the Translation BureaueMJ) Multilingual Services Division
Department of the Secretary of State of Canada
Department of the Environment Fisheries and Marine Service
Biological Station, St. Andrews, N.B. Biological Station, St. John's', Nfld.
1974
18 pages typescript
• MULTILINGUAL SERVICES CANADA
SECRÉTARIAT D'ÉTAT
BUREAU DES TRADUCTIONS
DIVISION DES SERVICES
(7'
a.,
DEPARTMENT OF THE SECRETARY OF STATE
TRANSLATION BUREAU
INTO — EN
English
TRANSLATED FROM — TRADUCTION DE
Norwegian
PUBLISHER — ÉDITEUR
Directorate of Fisheries
PLACE OF PUBLICATION LIEU DE PUBLICATION
DATE OF PUBLICATION DATE DE PUBLICATION'
YEAR ANNjE
PAGE NUMBERS IN ORIGINAL NUMÉROS DES PAGES DANS
L'ORIGINAL
209-217 NUMBER OF TYPED PAGES
NOMBRE DE PAGES DACTYLOGRAPHIÉES
ISSUE NO. HUME RD
VOLUME
'Bergen, Norway 1974 60 18
PERSON REQUESTING DEMANDE. PAR JIP 7 4 r7A —
Allan T. Reid.
DIVISION MULTILINGUES
ts • - 11.4 3131
AUTHOR — AUTEUR
K.F. Wiborg, K. Hansen and H.E. Olsen
TITLE IN ENGLISH — TITRE ANGLAIS
Iceland Scallop, Ghlamys Islandica (0.F. Muller) at ,Spitsbergen and Bear Island - Investigations in 1973 •
TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS) • TITRE EN LANGUE ÉTRANGÈRE (TRANSCRIRE EN CARACTèRES ROMAINS)
Haneskjell (Chlamys Islandica Muller) Ved Spitsbergen og BjernOya - Undersekelser i 1973
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.
Fiskets Gang
REFERENCE IN ENGLISH — RÉFÉRENCE EN ANGLAIS
REQUEsTING DEPARTMENT Environment TRANSLATION BUREAU NO.
MINIST .ERE-CLIENT NOTRE DOSSIER N ci 66iO37
Fisheries Services PMJ • TRANSLATOR (INITIALS) BRANCH OR DIVISION TRADUCTEUR (INITIALES) DIRECTION OU DIVISION
.YOUR NUMBER •
VOTRE DOSSIER NO
DATE OF REQUEST DATE DE LA DEMANDE
50s-200-10.6 tHEy. z/e6)
7030-21.020-I5 3 3 3
I
DEPARTMENT OF THE SECRETARY DF STATE
TRANSLATION BUREAU
MULTILINGUAL SERVICES
DIVISION CANADA
SECRÉTARIAT D'ÉTAT
BUREAU DES TRADUCTIONS
DIVISION DES SERVICES
MULTILINGUES
CLIENT'S N0.NO DU CLIENT
D'PARTMENT DIVISION/BRANCH CITYMINISTERE DIVISION/DIRECTION VILLE
Environment Fi.sheries Services Otta;,a, `?nt.BUREAU NO.
NO DU BUREAULANGUAGE TRANSLATOR(INITtALS)LANGUE TRADUCTEUR ( INITIALES)
663037 Nor<<vegian PSITJ : `T I ';
Iceland Scallop, Chlamys Islandica (O.F. Nlüller) at Spitsbergen
and Bear Island -Investigations in 1973
Haneskj ell •(Chlamys - Is larrdi ca Alüller) Ved Spitsbergen
og Bj¢rnOya - Unders¢kelser i 1973
by
Kristian Fredrik Wiborg and Karsten HansenNorwegian Institùte for Marine Research, Bergen
and
Hans Edvard OlsenOffice for Experimental Fishing and Vessels, Directorate of Fisheries
Fidkets Gang 60 (11) : - 209-217 (1974)
ABSTRACT
WIBORG, K. F., HANsr•.N, K. o(,^ Otsr•.N,1•I. E. 1974. Haneskjcll(Cklamys isGmtlica N^IÜllcr) vcd Spitsbergen og 13jcornoya -Undersokelser i 1973. [Iceland scallop, C.'lrlamys islandica (O. F.MUller), at Spitsbergen and Bear Island -- Investigations in1973]. Ffskets Canq, 60: 209-217.
In August 1973 experimental fishing for Chlarays islandica offSpitsbergen revealed extensive fields north of the island andalso some concentrations on the western hanks. L'p to 1700scallops were t:ucen in '?U minute hnuls usitl;, a sc•allr,li c!n.-d,r
with an opening of 3.6 nt. At Bear Island fields discovered inprevious years were fished, viclding up to'?U00 scalloll< per h:lul.
Owing to the selectivity of the gear. mitinly sc•:Iil,)la (it) -
90 nim in diarneter were c.ilght. The age of the u•nllups wasestitnc:ted to hi• 10--15 ycars. C;rowth. ;!s deeluced fi•uru
ti(^iu:u r,r nzones, was nioderate at Bear Island and north ofand slower at the Mitra Bank.
ghts of aclductor muscle were'lii<^hest at Bcar'island, 913 and 18 g for scallops 70, 80 and 90 mm respectivch•. ASpitsbergen the, corresponding weights were mostly 7, 1O an13 g, but at the Mitra Bank only 4.5 g for scallops of 70 min
The scallops supposedly spa%^•ned in July; the regeneratingonads in 70-90 mm scallops .veighitig about 4-5 g at BeaIsland, 2-4 g at Spitsbergen and below one ,, on the \Iitr•Bank. The gonads «•eighecl more in male, than, in fenialscallops.
The scallop banl<s north of Spitsbcrgen and at Bear Islam
are supposed tci be very rich, but with it slow rate of rcgencra
tion. Commercial fishcrv is not vet profitable, Inainlv bcc:iwd
of the high costs related to the fishing and to the procrssin;
of the scallop meats. Future mCchanisatlon may diminish thi
cxhenses.
l1i`dEl?fTt^
; c:r
TF1 A C)i.,^ i...
^ftÎOflt:J:{^3 ;t s^•ti{:::11L'fl^505.-2 p0-1 0-3 1
7 6'n-: 1-CI20-ç .^9^
2
Introduction
The distribution of Iceland scallop around Bear Island and toward Hope
Island has been determined earlier (iUborg 1970) . Stocks of Iceland scallop off
Spitsbergen are known both from the literature (see Wiborg 1963) and from obser-
vations from trawlers and research vessels, but not in detail. Urider the
direction of H.E. Olsen, experimental fishing for Iceland scallop was carried out
off the west and north coasts of Spitsbergen and off Bear.Island with R/V
"FEIEBAS" (Hansen, Husa and Olsen 1974) in August 1973.
Material and Nethods '
The gear used for most of the trip was a commercial scallop dredge
("large dredge") bought in Iceland. It was described by Hansen, Husa and Olsen
(1974). The large dredge is.of triple construction (Fig. 1). Each part has an
.opening of 120 x19 cm, a flat iron with spikes underneath and a bag which on
the underside consists of steel rings linked together, 80 mm in diameter, and on
the top a net of nylon with 120 mm meshes. Shells smaller thari 80 mm will not be
taken nuant'itatirely, and seine large ^1^ellS will p robably aiSo go through the
- meshes in the nylon net.
On some stations a modified Baird-mussel dredge ("small dredge") was used,
and this had an opening of 100 x 26 ,cm and 120 x 26 cm (Niborg 1963). It had a
smaller mesh,size than the large rake.
The large dredge was to^•ved fo.r 200 minutes, the small dredge for 5-10 p-210
minutes. By comparing the catches off Bear Is land in 1968-69 (iViborg 1970) taken
with a small dredge, and from the same place in 1973 with a large dredge, it could
appear as if the latter is 4-5 times as effective, but this value must be taken
with reservations.
When the catches had been taken on board, rocks, debris and empty shells
were sorted out. and the scallops frozen whole in boxes or sacks. Before freezing
1
— During later processing the height of the shells (distance from umbo, the
was of the shell to the opposite outer edge of the shell) measured with calipers
Fig. 1. Tredelt shetlandsskrape (storskrape) til fangst av hane- skjcll. Pryer del liar z-ipning 120 x 19 cm. Foto: K. Hansen.
. [Triple Shetland scallop dredge used for catching Iceland scallops. Each part has an opening 120 x 19 cm. Photograph:
K. Hansen]. • .
tip
carried out up to 10-15 mautical miles from was
the size (height) of the shèlls was neasured in representative samples.
3
to the nearest mm, and the measurements grouped in 5 mm groups (eiborg 1963).
After thawing, the muscles and gonads were separated from the rest of the
animal and weighed to the nearest 0.1 g in'groups for each 5 .mm group. The gonads
from males and females were then weighed separately for each individual group.
In a sample from Spitsbergen and one from Bear Island, the muscles were
weighed individually for each 5mm group.
Age and growth were determined by counting and measuring growth zones.
Mrs. S. Johannesen assisted in working up the naterial.
Bottom Topography
Off Spitsbergen, dragging
shore at 40-90 m depth. The bottom consists mostly of rocks, also Mffle she115,
in some areas with growths of horn corals and barnacles. Conditions for dritgglng
.were difficult and the use of heavy duty gear was necessary. Off Bear 15.1a4çl
4
the bottom conditions were characterized as good (Hansen, Husa and Olsen 1974).
In 1968 and 1969 the bottom conditions were found to be variable (Wiborg 1970).
Temperature Condition
From the areas off Spitsbergen, sea temperature measurements are available p.211
for 1955-1963 (Blindheim and Ljiien 1972), for August-September 1966-1969 (Dickson
and Doddington 1969-1970), and August-September 1973 (Midttun, personal communica-
tion). In the areas where Iceland scallop are fished, the temperatures in August-
September at 30-100 m depth are up to 4.5 °C while in the winter off Ny-Aalesund the
temperatures have been measured down to -1.5 °C at 40-100 m. On the Iceland
scallop grounds off Bear Island the bottom temperatures are approximately within
the saine limits (Wiborg 1970).
The Extent of the Iceland Scallop Beds
The cruise with "FEIEBAS" was classified as experimental fishing and no
systematic mapping was carried out. A list of dragging station and catches was
given by Hansen, Husa and Olsen (1974). The areas fished and maximum catches
are shown in Figs. 2-5.
North of Spitsbergen catches of up tb 1600 s
were obtained at . 50-55 m depth with the large dredge and 240 scallops in 7
minute drags with the small dredge (Fig. 3A).. Further towards the southeast
(Fig. 3B), up to 1200 scallops were taken with the large dredge at 40 . m depth.
On Sjubreflaket >(Fig. 3C) the fishing was carried out at 59-73 m, and at 60 m up
to 1700 scallops were taken'in a haul. However, the catches were uneven and the
dredge was often caught on the bottom.
On Mitragrunnen ("Mitra Shallows") (Fig. 4 D, E) there were mostly small
or no catches made except for a single haul yielding 1600 scallops. In the area
around Forlandet (Fig. 4 F, G) the catches were also small.
scallops per 20 minute drag
5
Off Bear Island the fishery was carried out at a depth of 90 m in areas
mapped in 1968-69. Southeast of the Island (Fig. 5 H, I) the catches were un-
even, up to 2000 scallops per haul. East of the Island (Fig..S K), the catclies
were smaller, 50-200 scallops per haul. At Spitsbergen the Iceland scallops
were most often strongly colored and had thin shells, similar to those found in
Balsfjord near Tromsd,, while those off Bear Island were greyish white with thicker
shel ls .-
Size Distribution
North of Spitsbergen in area A (Fig. 3) scallops with a shell diameter of
60-95 mm, mostly 75-80 imn, were taken (Fig. 6). The difference in selection
between the large and the small dredge is most^clearly shown in the size-distri-
bution. More scallops under 60 mm were taken with thesmall dredge and the maxi-
mum size was about 70 mm.(Fig. 6, A22 x). In area B (Fig. 3) scallops taken with
a small dredge (Fig. 6, B 4 x) were smal ler than thos e-taken further north
(Fig. 6, A 2 x), maximum 60 mm, while the large dredge took catches with a
variable size distribution. 'j'hPre was no si.."2Dle cQrrelation of shell sizes with -P -. 212
denth.
On Sjubreflaket (Fig. 3 C) there were large differènces between shell
sizes in catches taken with the large dredge and the small dredge while the dif-
ferences are not so obvious in Mitragrunnen (Fig. 4 D,'E),where the scallops were
$ Ÿ ler in catches takell with botii types of gear. Near aTcsjief j iet ( icsJ ï c
Mountain) (Fig. 4 G), the Iceland scallops were 65-95 mm with a maximum of 80 mm.
At Bear Island the shells in the southeast measured 70-95 mm with a maximum of
80-85 mm (Fig. 5 H, I); in the east a little smaller. Since no hauls were made
with the small dredge at Bear Island, it is difficult to make a comparison with
the conditions in 1968-69. In those years scallops with a shell size of 60-85 mm,
maximum 75 mm, were found in the southeast (IVâ.borg 1970).
6
• MOF FEN
- • Ofjr-..\ Ix 2 0 \--.../0
NORSKOVANE OA e.
:
/Do so
i x ( (. CP,.;
BAN KEN
• %
3 0
wo
0
78' 2_.1
3 0- FINS KARL S FORL AND
8 0° Od
30'
79b 00'
g° 11° 13°
Fig. 2. Provefiske etter haneskjell ved Spitsbergen i aug-ust 1973 med F/F «Feicbas». I) lugea fangst, 2) fangst, 3) omràde
" med to eller fiere trekk med fangst. [Experimental fishery for Iceland scallops at Spitsbergen in August 1973 with the R/V «Feiebas». 1) No catch, 2) catch,
3) area with two or more hauls with catch].
10° 11°i .
12° 13°
Fig. 3. Provefiskc ctter harieskjell ved Spitsbergen i aug-ust 1973. Antall skjcil pr. 20 ininutters trekk. 1) 0, 2) 1-10, 3) 11-100, 4) 101 —500, 5) 501 —1000, 6) over 1000, 7) omràde rued
rniddel ay to eller flere trekk. [Experimental fishery for, keland seaiiops at Spitsbergen in August 1973. Nuïnbcr of •scanops per 20 minute hauls. 1) 0, 2) 1-10, 3) 1 i —100, 4) 101-500, 5) 01-10O0, 6) more
i• - than IGGO, 7) a.:ca with average Of two or more hauls].
er.
11 s7
\ .
BJORNOYA
i • ;
G O
•"-
'■ e .....".
S.
:
e i '
117C
100
1. A
2 A 3 g.
4 • 50
I ......
t .
7
*>:01. V-2•1 ,
• Fig. 4. Provefiske etter haneskjell vecl SPitsbergen i august 1973. Syrnboler som pà Fig. 3.
[Experimental fishery for Iceland scailops at Spitsbergen in August 1973. Symbols as in Fig. 3].
74° 00'
Fig. 5. Provefiske etter haneskjell vcd Bjornnya i august 1973. Symboler sorn pà Fig. 3.
[Experimental fisher-y for iceiand scallops at Bear Island in August 1973: Symbols as in Fig. 3].
30'
20'
10' -I
--r- 19' 20°
8
Age Determinations
As earlier discussed (Wiborg 1963, 1970), it has been assumed that a
dark and light zone in the shell corresponds.to a growth zone (year). Johannessen
(1973) found two groups of small Iceland scallops near Troms'd in February-April
that measured 1.1-2.8 min and 7.140.7 mm respectively, and concluded that the
• smallest had come from the previous year's spawning in . June-July while the others .
were one year older. He demonstrated that growth zones existed both on shells
and ligaments, and found that alight winter zone was formed on the shell in
December-February. On the basis of this study, the shell meterial from the Bear -
Island area in 1968-69 was re-examined and it was found that what was earlier
thought to be the first growth zone consists of two zones with one ending 3-5 mm
from uMbo. The current experimental material has been similarly evaluated. A
correlation between the zones on the ligament and on the upper shell has also .
• •been found (Fig. 7). In some shell samples the growth zones of 50 upper shells
with same relative size distribution as the whole sample have been counted
(Fig. 8).
Few shells have less than 10 growth zones (year). Most have 10-14 with
an upper reliable limit of 16-17 zones. Also in samples taken with the small
rake the scallops seem to be old, although some shells have less than 10 zones.
Growth
The distance from umbo to the outer edge of each zone has been • measured
to the nearest mm.
Fig. 9 shows growth curves for Iceland scallops from some - localities. The
lbest growth was found southeast of Bear Island with 8-9 growth zones of 60 mm and
16 zones of 90 mm. The values are very close to those measured in 1968-69
(Wiborg 1970) when corrected for the nuMber of zones.
9
The second best growth was found north of Spitsbergen on Sjubreflaket
and east of Bear Island where 9-10 growth zones corresponded to 60 mm and 13-14
zones to 80 mm, while the shells from the outer part of Mitragrunnen (D 1) had
13 zones of 60 mm. Assuming that the scallops off Spitsbergen and Beâr Island
spawn in June-July, it could be assumed that the first growth zone corresponds
to the growth the rest of the year and, for instance, 9 growth.zones to an age
of. 8 1/2 years.
Muscle Weight
The weights of the adductor muscle in'relation to shell size are shown
in Fig. 10. The highest weights were found in the Bear Island_ area where -55 mm
p.214
shells had muscles weighing ca. 5 g; 70 mm - 9 g; 80 mm - 13 g.and 90 mm - 18 g.
These are similar to the weights found in -1.969 (Niborg 1970).. The weights are.
lower off Spitsbergen - 55 min -3.0 to 4.5 g; 70 mm - 7 g and 90 mm - 13 g. On
Mitragrunnen the weights were especially low; for 70 mm sheIls only 3.9 - 4.9 g.
The individual variations in weight can be c{uite large. At Bear Island
the following maximum weights were X:ound: - 6J. mm - 6.5 g; 70 mm - 11.5 g; .
80 rma - 17 g and 90 mm - .24. 5 g.
The scallops from the Bear Island area had a little higher inuscle weight
than those from the Andam Fjord in northern Norway (Wiborg 1970), while the
muscle weight in scallops from Spitsbergen can be compared to those from fjords
in Troms (Wiborg, not published). Fig. 11 shows that the adductor muscles from
Iceland scallops from Bear Island (B) were larger in relation to the shell size p.215
than those from Spitsbergen ( C) and Balsfjord (A).
Gonad Weight^; .
Fig. 12 shows the average gonad weight for some areas. The2
scallops southeast of Bear Island had the highest gonad weight, for shell size
60 nun - 2 g; 70 mm - 4 g; 90 mm - 5 g, while the weights from the areas north
10
80 20 40 60 80 100 20 40 60
STORRELSE 1 MM
Fig. 6. Storrelsesfordelinger av haneskjell ira Spitsbergen (ornràde A —G, Fig. 3. -4) og Djornoya (ornrAde H—K, Fig. 5). A 1 64 ni E I 44 m) skrapestasjoner og dyp, x) prover ira
smeiskrape. - [Size distribution oi :iceiand scallops (rom Spitsbergen- (area A —G in Fig. 3-4) and Bear Island (area H—K in Fig. 5.
I 64 E I 44 ni) stations and depth, x) sarripis irom small dredge).
. 11
•
• '")
-,■ ••••• .
•
/5:17. • . - .• . . 7, , ••
• /j/ I, ,•
, • , •
•
t.
'tee • Y • 1.• •
•
**; .1. •
f : • •.1'
•
';>Y•
•,r• • ' • . • • ...
fr!• d f y ct. é .• •
.. • . • • • v • •,' •• .•
.%•• ••D'
▪
• I t. • •
*1 • 41. .m■ • '
..• • •'•. •
j• •t '• t • ”• « -il . i••• '
▪
:«i• • • • 't ' '• e . . • ;•••\‘':' • .; .,•■ • '' • t•
•-• :5;.• -*" • • .- • • '• • ti.
sr-Z:1 ' 11• • • r t t tri t
: • .•
-"14.1.1 I
« ••••
.- • .: z.. ',- )- t. • . . • - .. .-.- ' . • '. 't,'. • • •• .' '', ..: . ,Z,. ". '.4 ......•'.. 1, ' ' ••••' .• . i.
7 1•4..1% .
',I, • 'l ", ? ; . . fetr ... ...s> . • .i . • ( . \ • ■ I. %'• ...(..\(• ■ Co,. ;•• •ii ..•".• ., . -:-•• le j" -'''.,,,,0 • '.. 1, '... :. t ., ..,•,• \ y.,...„...••••,p. , U..;,, ... t•.:' :.•‘`.-..t.. li,.';*-5;...t,, '•• ‘ ...?•k'. • '''''—';‘%%.,\. ; \• til : .:fe ..s: ;:4• ■ ......
I •
..: 1:*' • "' 't '.:.''':.(....(''.‘' ç''' •
•. : . ' e, -% \ .:› \e•,-- ? ' ,',.., • %. t ■ 1, . ,,, \Ill :.. , ,..1-.....,' . ,:i
i 1.1.14: . .. ; ••7 . •%.il' 4** '"; • V ; -4f.-1'..4. t li ' • ' t'• %. > V, ••%.••‘...'1-:`-,
- ..1•.' •: i ri`.. \e''.i- •-ee-47,1 . . t • , ', .„.
0 ' • . 1
•/•;/ • • •••
.
:•••
„
' e î
.,„j„ • •
f isV;
‘Vi y t • \.‘
' .
e•,••
•.1 :
• - ' I :
..
I li>•••• '•-•,:> ,..... 4, „ • l'
- - -'=•-••-■'•• ,.1•••...:.,........:;•:::-•:.-,:y...:t.I•i,•:1:::›.:,......, ........s.--ee e"'' '''' I
Fig. 7. Overskall og ligament av haneskjell fra Spitsbergen (omretcle F i Fig. 4). Ligament Prepare« etter jouANNEssEel (1973). .Overst: Skall 59 mm, ligament 3,0 mm, 9 vekstsoner. Nederst: Skall 70 mm, ligament 3,5 mm, 14 vekstsoner. NB. Siste sone nmr kanten av • skjellet. Foto: K. Hansen. [Upper shell and ligament (hinge) from Iceland scallops at Spitsbergen (area F in Fig. 4). Ligament prepared after joilANtsn:sszbt (1973). Top: Shell 59 mm, ligament 3,0. mm, 9 growth zones. Bottom: Shell 70 mm, ligament 3.5 mm, 14 growth zones. Note: Last zone near the edge of the ficli.
Photograph: K. Hansen]. . I ; . , I
•'/
20
10
30
20
10 ,
201
10
A2X
Es4X
Y4
201
10
30
20
10
30
20
10
C 2 X
01
201
10
20{
10I
30
20
10
D2X
VZ
h,---r -^ P r4 4! _, -4 6 8 10 12 14 16 4 6 8 10 12 14 16
- ANTALL ' VEKSTSONER
Fig. O. Aldersfordeling av hancskjcll fra Spitsbergen (omrAdzA-F i Fig. 3-4) og Bjornoya (omr3dc H-K i;"ig. 5).
Syinboler som p.% Fig. 3-6.[Age distribution of Iceland scallops from Spitsbergen (areaA-F in Fig. 3-4) and Bear îsland (area H-K in Fig. 5).
Symbols as in Fig. 3-6].
>
8
4
â
soin pA Fig. 3-5.
40 60 80 tOG 40 60 80 100ST9RRELSE i MM
Fig. 10. Veict av luïcKCmuskcl i forhold til sl ^.lis.6rrclsc hoshaneskjelL 'f'il venstre: IN•liddelverdier for Spitsbergen (omrlde
A-F) og Bjornoya (omrâde H-K). Innsirklct: Enkeltverdi.Til hoyre: Ivlidçiclverdicr og standardavvik for en prove IraSpitsbergen (kryss) og en fra Bjornoya (fyilte sirkier). Bokstavcr
[Weight of adductôr muscle in relation to shell size in Icelandscallops. Left: Mean values at Spitsbergen (area A-F) andBear Island (area 2-3-K). In circle: Single value. Right: Meanvalues and standard deviations in single samples from Sp'sts-eergen (crosses) and Bear Island (black dots). Letters as in
Fig. 3-51.
9d
80-
70
60
20-I
10i
A---A
H o-pt( p............A
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17NTALL VEKSTSONER
, . ^ .
Fig. 9. Vekstkurver for hancskjcïl ved Spitsbergen og Bjornoyabasert p.î m3linger av vèkstsoncr. Bokstaver og tall som p.I
Fig. 3 -6.[Growth curves or Tcelanci scallops at Spitsberben and BearIsland based on measurcrnents of growth zones. Symbois as in
:i.ïg. 3 -6].
P1a
•/30
20
10
20]
j 10
- .13
•
. • . .•-•_ •
r
• !/.. ,
•
f tie
• . 1 . t
•
1••ur.- .Ç,:. %:A> ,,r
6
—5
I- s 41
3 -.
2 4
1
4 La
3
2 • 12 0
41 0 o
-I- A- • 0
2 A A A •
0 • • 9 0
0 2
At3 o C o
0E •
F
H X
K 9
X •
Gjennomsnittsvekt av hann- og hunngonader
Ac A
A 9.
H cf
H -I- 7 O
•
*.• • •
-` -
I • Fig. 11. Lukkemuskel og gonade av haneskjell. A) Balsi'jorden 26. mai 1962, B) Bjornoya (omrà.cle, H i Fig. 5) 21.'august 1973, 0) Spitsbergen (omràde A i Fig. 3) 11. august 1973. Merk gorskjellen i storrclsen av gonader og : muskier i forhold til skall-
storrelse. Foto: K. Hansen:. [Adductor muscle and gonad from Iceland scallops. A) Balsgjord 25 May 1952, 13) 1973, C) Spitsbergen (area A in Fig. 3) 11 August 1973. Note the difference in size
to shell size. Photograph: K. Hansen]:
• e.e:
; • Bear Island (area H in Fig. 5) 21 August of gonads and. adductor muscles in relation
! ; !
I
60 7 .0 8;0 90 100 50 60 70 eo 90 100
6
—5
+ A
el A
A A
50 STORRELSE bms4
- . Fig. 12; Gonadevekt hos haneskjell i august 1973: Til hoyre:
( 6' + --- r) Lra • 9
Spitsbergen (omràde A —F i Fig. 3-4) og Bjornoya (omdtde H—K i Fig. 5). l'il venstre: Gjennomsnittsvekt av hann- og hunngonader fra Spi tsbergen (oturâile A i Fig. 3) og 11;ornoya
(omràde H i Fig; 5). Innsirklet: Enkeliverdier. [Weight of gonads from Iceland scallops in August 1973.
Right: Average weight of male and female gonads (
from Spitsbergen (area A— le in Fig. 3 --I) and Bear Island
(area H—K in Fig. 5). Left: Average weights of male and female gonads from Spitsbergen (area A in Fig. 3) and Bear
Island (area H in Fig. 5). In circle: Single values 1.
and west of Spitsbergen were lower, .60..mm - ca • 1.5-1.7; 70 mm - 2 g and 90 mm -
3 g. An exception is Mitragrunnen where the gonad weights were especially low,
- below 1 g.
The male gonads weighed more. than the female and the difference could at
times be quite large (Fig. 12). At Bear Island the female gonads, shell size .
70 mm, weighed 4 g; the male gonads over 5.5 g; 80 MU - ca. 4 g and 6 g; 90 mm -
ca. 5.5 g and a little over 7 g. There were large individual variations. The
differences are note quite as distinct at Spitsbergen. It is not known if the
difference is constant the whole year. Male gonads possibly need a shorter
period to regenerate than the female. It is likely that the Iceland scallops
off Spitsbergen and Bear Island had spawned some time before or just before
the samples were taken and that the gonads could have been larger (heavier) both
earlier and later in the year. The relative size of the gonads can otherwise
given an indication of if the scallops had spawned or not. Skreslet and Brun
(1969) and Skreslet (1973) used the relationship.
çsonad weight x . 100 •
weight of (soft parts gonads)
as a gonad index. In Balsfjord near Tromsô the Iceland scallop usually spaWns
in the end of June, and the gonad index then goes from ca. 40 to 15-18 (Skreslet
1973).
From the experimental material described here, the relationship
' gonad weight (G)
muscle weight (M) gonad weight (G)
has been used.
Data from Andamsfjord (Wiborg 1970) and Balsfjord (Wiborg, unpublished)
14
x 100 (Table 1)
are also included in the table. The scallops tad probably not spawned in Andams-
fjOrd on June 16, 1972. In Balsfjord (see Fig.. 11) the index on May 26, the saine
56 46
26 t
31 . 22
27 29
27
15
year, was
measuring 80-85 nun. Larger scallops spawn earlier than smaller animals
according to Skreslet and Brun (1969). .
At Bear Island and Spitsbergen the index was low in August 1973, down to
half the values for Andamsfjord and Balsfjord (see gonads on Fig. 11). Even if
the conditions in-northern Norway cannot be compared to those further north
without reservations, it is likely that the Iceland scallops near.Spitsbergen
and Bear island had finished spawning in August 1973. Approximately the same
index was found at Bear Island in September 1969; for shell sizes 75, 80 e 85 -
and 90 mm, the indices were respectively 32, 25, 26 and 24. .The fact that
larger scallops have a lower indax.than the smaller ones could be due to factors
such as different condition or later'regeneration after spawning.
• . . . . I
G Tab* 1. Gclnadeindeks:
G x 100 hos haneskjell fra forskjclligellokaliteter.
+ M • . Gonad weight (G) . •
[Gonad index: X aoo • Gonad weight (G) + Muscle weight (M) I
' in :Iceland scallors from various .localities}.. 1 .
approximately just as high . as in.AndamsfjOT:d, except for scallops
Omràde Dato 60-70 mm
indeks
Skall4yde
min rideks
Nord-Norge Andamsfjord 16. juni 1962
Balsfjord 26. mai » 48 47, 30, 28 (75, 80, 85 mm)*
Spitsbergen Omràde A (Fig. 3)
• (Fig. 3) _ » C (Fig. 3) » D (Fig. 4) » F (Fig. 4)
10. august 1973 10.=-11.
7. .» » 17. » » 9. » »
23 20 22. ._ 21 18 17 25
Bjornoya
Orriràde It (Fig. 5) 22. » »
» J (Fig. 5) 23. » »
» K (Fig. 5) 25. » »
16
Commercial Utilization
The Iceland scallop beds at Bear Island are estimated to contain 2-5 x 109
individuals in the areas with the densest population (Anon.•-1974). The estimate
is possibly too low, since it was based on catches with a dredge that usually
takes only a few per cent.of available animals. On the other side, the stock
needs a long period of time, at least 10 years, to renèw itself so that the
yearly recruitment is hardly more than one tenth. Based on a muscle weight of
10 g, this would total-2000-5000 tons of edible muscle. In practice, it would,
however, be possible only to take a small part of this
No systematic mapping of the beds has been carried out in waters off
Spitsbergeri. The area fished to the north of Spitsbergen had an area of around
69 km2. The catches here were at times as high as off Bear Island. {9ith an_
estimated density of 10 scallops per m2, this totals 6.9 x 108 animals or 6900
tons of edible muscle. It is possible that the beds extend over a larger area
so that the stock could be of the same order of magnitude as near Bear Island.
The areas along the west side of Spitsbergen and around Forlandet seem to be of
lesser importance both quantitatively and qualitatively.
Some of the scallop samples from the catches taken by the "FEIEBAS" were
weighed whole, inclusive shell growths, in order to calculate net yield of muscle
(Table 2).
TabeI1 2. Ncttoutby.tte av muskcivek2 i prosent, og muskelvektav liancs'.cjeli over 65 mm; ved Spitsbergen og Bjornoya i august1973. [Nez yie:d o: meat (adductor muscle) in percent, and4Vt;ÿÎTi o'i :IàliScics ii-. g ïrviYi rce.ariQ scallops :aYS.:r tR.Tn GJ mm
at Spiwbcrgen and Bcar ïs:and in August 1973j.
0mrltc;e
Spilsbergen0mr:tclc A 2 (F ig. 3)
» A 3 (Fig. 3)
» A 4 (Fig. 3)
i) D I (Fig. '`-)
13jnrnoya
Qror:!dc I-i (F iti. 5)
Ii'roscnt Muskelvekt i g
Iutioytte1 - I Midcicl I Varir.sjon
11,0 7,7 6,3-11,610,0 9,6 6,2-12,410,7 8,6 7,8-14,89,0 3,6 3,4- 4,8
11,5 . 14,5 10,2-17,8
•
17
The net yield varied between 9% and 11.5% while the average muscle
weights showed larger variations; 14.5 g southeast of Bear Island, 8-10 g north
of Spitsbergen, but only 3.6 g on Mitragrunnen .
Outlook for a Commercial Fishery
During the experimental fishing cruise with - "FEIEBAS", up to 20 hauls
were made per day and catches as high as 2000 scallops were made in a 20 minute
haul. Daily catches were as high as 10,000 scallops (Hansen; Husa and Olsen
1974). With an average weight of 10 g per muscle, a catch of this magnitude
Would yield ca. 100 kg edible muscle, with a landed value of 2-3000 kroner
according to prices today (1 N.kr = za. 0.18 Can, $).
Before the Iceland scallop fishery could be profitable, many problems
must be solved. The catches could probably be increased both by extending the
number of hours fished and by using mure or'perhaps larger rakes. But the main
problem will be the processing. It is not realistic to sell the animals whole.
The edible part, i.e., the muscle and perhaps also the gonads must be separated
from the shell; Manual handling would be too costly and time consuming. Up to
100 scallops must be opened to yield one kg of edible muscle. On Iceland a
meChanical shucking machine mounted ashore has been taken in use. It costs
between 0.3 and 1 million kroner. - The best solution would be to have shucking
machines installed on board so that the catch could be processed continuously.
By .cooling the scallops, they can be kept fresh up to a week so.that a larger
load can be taken ashore for processing.
Freezing of whole scallops is - also a possibility, but would require
thawing before precessing, and no data are available on if the muscle could be
refrozen or if cooking or canning is necessary for further storage.
18
: LITTERATUR
ANoN. 1974. Matnyttige muslinger. Fisken og Havet, 1974
(Sternummer) : 95-98. BLINDIIEINI, J. and L.J0EN, R. 1972. On the hydrographie
conditions in the Spitsbergen current in relation to ice
distribution during the years 1956-1963. P. 33-41 in KARLSON, T. cd. Sea ice, Proceedings of an international
conference. National Research Council, Reykjavik.
DICKSON, R. R. and D0001NGTON, T. C. 1968. Hydrographie conditions off Spitsbergen in the summers of 1966 and
967. Amis biol. Copenh., 24: 24-29. - 1970. Hydrographic conditions off Spitsbergen in
the summers of 1968 and 1969. Ands biol. Copenh., 26:
26-32. HA_NsF.N, K., HusA, I. og OLSEN, H. E. 1974. Rapport fra
• forsoksfiske etter haneskjell ved Svalbard og Bjornoya i tiden 4;8. --25.8. 1973. Fiskeridirektoratet. Fiskeribedriftens
frrsoksfond. Rapp., 1974 (under trykning). JOHANNESSEN, O. H. 1973. Age determination. in Chlamys
islandica (O. F. Müller). ilstarte, 6: 15-20.
SKRESLET, S. 1973. Spawning in Chlamys islandica (O. F. Muller)
in relation to temperature variations catts.:d by vernal
meltwater discharge. Astarte, 6: 9-14.
— and BRUN, E. 1969.- On the reproduction of Chlamys
islandica (O. F. Müller) and its relation to depth and
temperature. Astarte, 2: 1-6. WIBORG, K. F. 1963. Some observations on the Iceland scallop
Chlamys islandica (Muller) in Norwegian waters. FiskDir.
Skr. Ser. HavUnders., 13 (6): 38-53. — 1970. Utbredelse av haneskjell . (Chlamys islandica Muller
pà Bjornoybankene. Fiskets Gang, 56: 782 —788.
Anon. 1974. Edible shellfish.' Fisken and - Havet, 1974 (Special issue): 95-98.
Hansen, K., Husa, I., and Olsen, H.E. - 1974. Report from experimental fishing
for Iceland scallop off Svalbard and Bear Island in the period 4/8-25/8,
•1973. Directorate of Fisheries, Fishing Industry Experiment Fund. Rep. 1974
(in press). - .
Wiborg, K.F. 1970. Distribution of Iceland scallop (Chiamys islandica Mulle -r)
on the.Bear Island banks. Fiskets Gang 56: 782-788.