Fróðskaparrit - 01.01.1992, Side 14

18
THEINTERNATIONAL RESEARCH ...
was 33% in the liver, ranging from 3% to
62%, the lowest fractions being encoun-
tered in the older individuals. Cadmium
concentrations were very high and higher
than those found in other cetacean species
anywhere else, even from highly industri-
alised areas. In foetuses concentrations of
Hg and Cd were lower than in the mothers,
but they were already cumulative. A trans-
fer from mother to offspring is likely to be
observed.
The concentrations in Hg, Cd and Zn
varied significantly between schools and
the Cd particular may be used as a tracer of
the school history. Two schools (Tórshavn,
081087; Øravík, 150986) showed signifi-
cantly higher concentrations of Hg in the
liver than the remaining schools. The
school landed in Tórshavn (081087)
showed also significantly lower levels of
Cd and Zn in the liver than the remaining
schools, while a school landed in Miðvágar
(240787) showed significantly higher con-
centrations of Cd and Zn.
Similar variations between schools were
found in Cd concentrations in milk, which
results in a different exposure of the new-
bom as soon as it begins suckling. Milk
could represent another way of elimination
of Cd, which could explain the significant-
ly lower Cd concentrations observed in the
liver of lactating females.
Comparison of levels of Cd between
schools continues, in order to confirm dif-
ferences and verify hypotheses on the exis-
tence of several populations of pilot
whales.
Future work will try to determinate,
through histo-pathological analysis of the
kidney, whether Cd has toxic effects in
pilot whales. Parallel to this, the metabo-
lism of Cd will be investigated by qualita-
tive and quantitative evaluation of metallo-
proteins, the soluble forms of Cd. The lev-
els of methyl-Hg in the different organs
will be determined, and an analysis of the
system of detoxification by selenium will
be studied. An in-depth study of mother-
offspring transfer is planned, particularly
for methyl-Hg. It has already been shown
that the levels of CH^Hg in foetuses could
be determined by fumace atomic absorp-
tion spectrometry (Caurant, pers. comm.).
Caurant, F. in prep. Contamination par les metaux lourds du
globicephale noir (Globicephala melas) peche aux iles
Feroe. Doctoral thesis, University of Nantes.
Caurant, F., Amiard-Triquet, C. and Amiard, J.-C. In press.
Factors influencing the accumulation of metals in pilot
whales (Globicephala melas) off the Faroe Islands.
Rep.int.Whal.Commn (Special Issue 14).
Caurant, F. and Amiard-Triquet, C. In press. Cadmium con-
centration in pilot whales, Globicephala melas: source
and potential hazard to the species. C.R.Acad.Sci. Paris.
Caurant, F., Amiard-Triquet, C. and Amiard, J.-C. In press.
Ecological and biological factors controlling the con-
centrations of trace elements (As, Cd, Cu, Hg, Se, Zn) in
delphinids (Globicephala melas) from the North
Atlantic Ocean. Marine Ecology Progress Series.
Jean-Caurant, F. 1987. Etudes preliminaires de la contami-
nation par les elements traces du dauphin Globicephala
melaena. J. Rec. Oceanogr. 12(3-4): 85-89.
Jean-Caurant, F. and Amiard-Triquet, C. 1991. The con-
sumption of marine mammals’flesh as a way of expo-
sure to cadmium and mercury in Faroese population. In:
J.G. Farmer (ed). Heavy metals in the environment, 1.
CCP Consultants, Edinburgh: 464-467.
Jean-Caurant, F., Amiard-Triquet, C. and Amiard, J.-C.
1989. Ecological and physiological factors influencing
the metal contamination of pilot whales (Globicephala
melas) from the Faroe Islands. Paper SC/41/SM21 pre-
sented to the IWC Scientific Committee, May 1989
(unpublished). 1-21.
Schintu, M., Jean-Caurant, F. and Amiard, J.C. 1992.
Organomercury determination in biological reference
materials: Application to a study on mercury speciation