Fróðskaparrit - 31.12.2000, Blaðsíða 146

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INDIVIDUAL ANALYSES OF MERCURY AND ORGANOCHLORINES
IN MARINE MAMMALS FORM THE FAROEISLANDS
Grey secils
The seals were shot in various places
around the Faroe Islands during the sum-
mer months of 1993, 1994 and 1995 in con-
nection with a study of their summer diet
(Mikkelsen, 1998). Muscle and blubber
samples were taken high on the abdomen
near the chest bone. The samples were
wrapped in aluminium foil and the parcels
were put in plastic bags and stored in a
freezer at <-I8°C.
The age of some of the seals was deter-
mined by means of the lower canine teeth.
A growth curve of age vs. body length was
constructed from these seals (Hewer,
1963). The age of the remaining seals was
then estimated using this growth curve.
The males become sexually mature at the
age of four to five years, but generally they
do not become sexually active until they
reach the age of eight years because of
body size dominance and local conditions
at the breeding grounds (Mikkelsen, 1998).
As a consequence, only males older than
eight years of age are included in the group
of adult males. All pregnant seals were
placed in the adult females group.
Chemical analyses and
sample pre-treatment
Mercurv
The analyses were conducted at the labora-
tory of the Food and Environmental
Agency of the Faroe Islands using borhy-
Table 5. PCB in white-sided dolphins as single congeners in pg/kg Iw and as Aroclor 1260 equivalents in
mg/kg Iw. The results are shown with mean and standard deviation (bold) and minimum and maximum values
for the groups of adult and juvenile, females and males.
Talva 5. PCB í hvítskjórutum springarum sum einkult kongen í pg/kg av feitti og sum Aroclor 1260 eindir í
mg/kg av feitti. Urslitini eru víst sum miðalvirði við standardfrávikum (við feitari skrift), eins og lægsta og
hægsta virði fyri teir fýra undirbólkarnar av hon- og hannhvølum, hvølpum og vaksnum er víst.
Aroclor 1260 (mg/kg lw) 28 52 99 101 105 118 128 138 153 156 170 180 183 187
juv. females 12 32 331 289 359 114 151 170 987 1408 88 113 324 101 459
std. dev 5 9 86 128 64 40 80 27 385 571 42 44 145 56 213
N = 6 21 212 113 269 54 91 127 515 708 42 51 149 38 228
7 19 41 418 440 471 167 302 210 1450 2124 150 174 577 192 734
ad. females 3 8 44 41 72 23 37 37 234 368 42 100 235 73 259
std. dev 2 4 21 19 28 9 16 18 121 183 17 49 135 43 134
N = 1 4 24 23 46 15 19 14 95 149 17 39 76 24 97
8 6 14 79 79 113 39 73 68 459 675 58 166 444 135 432
juv. males 24 40 556 670 404 125 81 253 1923 2693 117 218 577 197 836
N = 1 na na na na na na na na na na na na na na na
ad. males 45 38 584 1202 486 180 196 433 3436 5131 325 669 1661 582 1831
std. dev 15 14 150 409 146 69 100 135 1085 1798 128 274 640 236 626
N = 19 24 363 455 261 58 57 183 1473 2133 113 216 612 211 773
8 70 61 875 1863 805 289 434 639 4946 8602 520 1012 2549 948 2801