Fróðskaparrit - 01.07.2004, Blaðsíða 112

110
MERCURY IN THE FAROE ISLANDS — A REVIEW OF AVAILABLE DATA
planation could be differences in size. Also
apparent is a tendency of decrease in the
mercury concentration when cod data in the
period 1979 to 1992 are regarded. This
could stem from variability in the average
size the various years, but could also stem
from actual decreases of environmental
mercury. In order to exclude some of this
uncertainty a new selection of the 1979-
1992 data were made by including only re-
sults representing fillets from 40 cm to 60
cm, and preparing a new graph, Fig. 9. In-
specting the time-trend in the new fígure re-
veals that the tendency seen in Fig. 8 is now
even more pronounced. Thus it is assumed
that there were overall higher concentration
of mercury in cod from the Faroese shelf
area during the eighties than in the late
nineties and the present levels.
Overall, the level of mercury in cod from
the Faroese shelf area the last 5-10 years
may be described with the range 0,01 - 0,04
mg/kg muscle (Table 11). This is low com-
pared to for instance mercury in cod in the
Lofoten area in Norway, where in the same
period the concentrations measured as part
of JAMP have been in the range 0,04 mg/kg
to 0,13 mg/kg muscle (Green et al., 2000).
Compared however, to cod (Gadus m.)
from the Nuuk area, Greenland, where the
muscle mercury in 35-43 cm físh was 0,014
mg/kg, the level in Faroese cod is of equal
magnitude.
Sculpin, Myoxocephalus scorpius, has
been analysed as part of the AMAP pro-
gram in 1999, 2000 and 2001 (Olsen et al.,
2003). The sculpin fishery for this monitor-
ing has taken place in Kaldbaksfjørd, at
various sites, selected so as to avoid sewage
discharge sites. The fish has been analysed
either in pools combining físh of similar
length or as individuals. The results so far
have been highly variable in particular with
respect to mercury, Fig. 10, but also cadmi-
Fig. 10. Mercury and
selenium in sculpin liverfrom
Kaldbaksfjord are shown in
mg/kg ww along witli error
bars depicting the standard
deviation (Olsen et al., 2003).
2,5 ■ Mercury
□ Sclcnium
20-25 25-31 20-25 25-31 20-25 25-32
cm, cm, cm, cm, cm, cm,
1999 1999 2000 2000 2001 2001