The Davis Strait - DCE - Nationalt Center for Miljø og Energi

Figure 4.2.3. Greenland halibut
(Reinhardtius hippoglossoides)
larvae abundance (N m -2 ). The
coloured dots represent abundance
values from different studies;
red, blue, dark-grey and
yellow dots: from surveys in May-
July 1996-2000 (Munk et al.
2000, Munk et al. 2003, Munk
pers. comm. and REKPRO-data
from C. Simonsen and S.A.
Pedersen pers. comm.). There
are indications of relatively high
abundances offshore compared
with inshore/coastal areas.
70
66°N
64°N
60°W
60°W
Larvae, Greenland halibut
(Reinhardtius hippoglossoides)
Survey period
62°N
60°N
July 2000
( May 2000
h( June 1999
h( June-July 1996
Abundance (N m -2
)
# No observations
h( 0.004 - 0.05
h( 0.05 - 0.10
h( 0.10 - 0.15
h( 0.15 - 0.20
h( 0.20 - 0.29
Assessment area
0 75 150 Km
#
h( (
# # # # # # h( ( # # # # # #
h( (
( h( ( h(
#
( h( h( (
( h( h( ( h( ( ( h(
( h(
# #
h( (
# # h( ( h( ( # # # h( ( #
#
h(
h( ( h(
h( ( ( ( h( h( ( ( h( # h( ( # h( ( # #
# ( h( h( h( ( h(h( (
h( (
h( # #
h( ( h( (
#
Greenland halibut larvae concentrations in the upper water column are relatively
high south of 68° N, while within the major part of the assessment area
they are low in June-July, based on Figure 4.2.3. Other fish larvae that
have been studied include sandeel (Ammodytes spp.), which were very numerous
particularly on some of the banks (Fig. 4.2.4) (Pedersen & Smidt
2000).
In 1996-2000 studies on fish larvae in West Greenland waters were carried
out (Munk et al. 2000, Munk et al. 2003, Munk pers. comm., and REKPROdata
from C. Simonsen and S.A. Pedersen pers. comm.). These studies did
not find the sandeel larvae concentrations as reported by Pedersen & Smidt
(2000). They found large interannual variation in abundance of polar cod
larvae and confirmed the distribution of Greenland halibut larvae as reported
by Pedersen & Smidt (2000) (Fig. 4.2.3, 4.2.5). Recurrent concentrations
areas of fish larvae were not located, and generally there seems to be large
variation in distribution and abundance of fish larvae between years. Although
planktonic organisms are supposed to move with the currents there
seem to be retention areas over the banks, where plankton is concentrated
and entrapped for periods (Pedersen et al. 2005).
( h(
#
h(
h( ( ( h( (( h( ( h( ( h( h( ( h( (
h( ( ( h(
( h( ( h( h( (
(
55°W
(
55°W
# # # # #
h( ( h(
( h(
h( ( h( ( #
( h( (( h(
( h( ( h( # h( ( h( ( h( ( ( h( ( h( #
( h(
#
( h(
h( (
h( (
#
#
# # #
( h( # # # h( ( ## # #
#
#
#
#
#
50°W
50°W
68°N
66°N
64°N
62°N