Fróðskaparrit - 01.07.2004, Page 118

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MERCURY IN THE FAROE ISLANDS — A REVIEW OF AVAILABLE DATA
Sampling Sampling area n matrix Hg, mg/kg ww
Black guillemot *a Nov’95-Feb’97 Hestoy/Sveipur 88 liver 0,74
Black guillemotc Jun’96-Aug’96 Hestoy/Sveipur 33 liver 0,7
Eider *a Apr’-96-Feb’97 Tangafjørð 52 liver 0,26
Shag *a Nov’95-Nov’96 Sandoy 40 liver 0,41
Fulmar pullusb Aug’97 Vestmanna 15 liver 0,11
Fulmar pullus b Aug’97 Nólsoy 25 liver 0,19
Fulmar, juveniled Sep’99 Viðareiði 10 muscle 0,52**
* Geometric means are given. ** mg/kg dw. Table 13. Mercury in seabirds from the Faroe Islands (a.Dam, 1998b; b.Larsen and Dam, 1999; c.Olsen et al., 2001, d. Dam et al., 2001).
did not indicate that this was accompanied
by any negative impacts (Norheim, 1987;
Norheim and Borch-Iohnsen, 1990).
Liver mercury in black guillemot from
Greenland in 1984-1986 (Nielsen and Di-
etz, 1989) and 1999 (Riget etal., 2003) was
found to be in the range 0,5-0,64 mg/kg ww
and 0,61 (0,19 mg/kg respectively, i.e. in
the lower end of the range found in the
Faroese birds. Whereas in eider liver from
Greenland the mercury concentration was
in the range 0,48-1,19 mg/kg which is part-
ly overlapping the range found in the
Faroese and partly exceeding this range
(Nielsen and Dietz, 1989).
Included in the Table 13 are also results of
not yet fledged fulmars. Young fulmars are
part of the Faroese local diet, and are taken
in large numbers each autumn. At the time
of catch, these young birds have not started
food seeking on their own, but have been
fed by parents in the nest until they were
caught sitting on the sea surface. The ful-
mars in the table were taken in Nólsoy and
Vestmanna in 1997, and were analysed for
heavy metals as well as organochlorine pol-
lutants (Larsen and Dam, 1999). In 1998
and 1999, more samples of fulmars were
taken for extensive analyses of persistent
organic pollutants in various tissues, and in
a batch of 10 juveniles from September
1999 muscle mercury (Table 13) and cad-
mium was analysed (Dam et al., 2001).
Eggs
Analyses of seabirds’ eggs were done in a
few studies in the seventies and eighties on
mainly great skua (Stercorarius skua) by
Bloch et al. (1987). In the late nineties a
systematic sampling and analysing of pol-
lutants in black guillemots eggs were im-
plemented as part of the AMAP work
(Hoydal and Dam, 2003). Yearly sampling
of ten eggs has been done in two colonies,
in Koltur and in Skúvoy since 1999 and
continues.
Analyses of the black guillemot eggs in-
dicate that in recent years, there may be a
decreasing trend in mercury concentration