Fróðskaparrit - 31.12.2000, Blaðsíða 93

NØRINGIN HJA TOSKINUM A LANDGRUNNINUM:
GÝTINGARØKI, EGGSPJAÐING OG FØÐIN HJA LARVUNUM
97
Table 5. Mean relative numbers ofprey groups in
cod larvae on the Faroe Shelf during 29-30 May
1995. Mean larval length and standard deviation
was 12.2 ± 2.4 mm. N = 60
Talva 5. Miðal lutfalsligar nøgdir av ymiskari føði
hjá toskalarvum á landgrunninum 29.-30. mai 1995.
Miðalstøddin og standardfrávik á larvunum var
12,2 + 2,4 mm. N = 60.
Prey group Relative numbers (%)
Copepod eggs 3.2
Copepod nauplii 14.9
Calanus (CI-CIII) 21.3
Acartia 29.8
Temora 11.7
Other copepods 18.1
Other 1.0
Egg production of Calanus finmarchicus
The mean egg production of C. finmarchi-
cus on the Faroe Shelf and slope in late
April 1997, 1998, and 1999 was highly
variable horizontally. It was highest in the
western and north-western shelf and slope
regions, with a mean production per stra-
tum of 150-200 eggs mf3 day"1 (Fig. 6). It
was markedly lower in the eastern and
southern regions (50-100 eggs m'3 day'1),
and lowest in the central shelf region (<25
eggs m'3 day'1).
Discussion
The two spawning grounds that were iden-
tified in spring of 1995 and 1999 (Fig. 2)
are, to a large extent, identical to what has
been reported earlier (e.g. Joensen, 1954;
Joensen and Táning, 1970; Jákupsstovu
and Reinert, 1994). Cod spawn in two
main areas, one western and one northern.
The northern spawning ground seems to
cover a much larger area than the western
one. As mentioned earlier, Fig. 2 does not
necessarily show all the high concentra-
tions of spawning cod, as there may have
been high concentrations between the
sampling stations. However, the maps
clearly show the positions of the main
Eggs m'3day
_ <25
i; 25-49
Z 50-74
■ 75-99
■ 100-149
■ 150-199
Fig. 6. Mean egg
production ofCaianus
finmarchicus in the
upper 50 m ofthe
water column, per
stratum, on and
around the Faroe
Shelf 17-29 April
1997-1999.
Mynd 6. Miðal gýting
hjá Calanus finmar-
chicus í ovastu 50
metrunum av sjónum,
pr. punt, á og rundan
um føroyska land-
grunnin í tíðarskeiðin-
um 17.-29. apríl 1997-
1999.