NOT TO BE CITED WITHOUT PRIOR REFERENCE TO THE AUTHORS

SC/D06/J28

Yearly trend of trace element accumulation in liver ofAntarctic minke whale, Balaenoptera bonaerensis
GENTA YASUNAGA*, YOSIHIRO FUJISE*, RYOKO ZENITANI*, KATSUHISA HONDA*# AND HIDEHIRO KATO*+* The Institute of Cetacean Research, 4-18, Toyomi-cho, Chuo-ku, Tokyo 104-0055 Japan.
*# Department of Environmental Science for Industry, Ehime University, 3-5-7, Tarumi, Matsuyama-city, Ehime, 7908566, Japan.
*+ Tokyo University of Marine Science and Technology, Faculty of Marine Science, 4-5-7 Konan, Minato-Ku, Tokyo
108-0075, Japan.

ABSTRACT
Concentrations of toxic elements (Hg, Cd, Pb and Ni) and essential elements (Cu, Zn, Fe and Mn) were
determined in 1,056 livers of Antarctic minke whales (Balaenoptera bonaerensis) taken from Antarctic
Areas IIIE, IV, V and VIW during 1988/89 and 2004/05. The ranges of concentrations for each element
were, in μg/g wet wt: Hg, <0.005-0.43; Cd, 0.089-66; Pb, <0.3-0.7; Ni, <0.1-0.3; Cu, 2.8-14; Zn, 18-103;
Fe, 1.6-11000; Mn, 1.4-7.4. Gender differences in Fe and Zn levels were observed in livers of Antarctic
minke whales. A stepwise multiple regression analyses of Hg and Cd levels in males identified sampling
years, age and sampling longitude as main effective factors. Although it has been known that essential
element levels in animals are maintained constant due to homeostasis, essential elements wereindependent of sampling year (Cu, Zn), age (Cu, Fe, Mn), longitude (Cu, Zn , Fe, Mn) and latitude (Mn).
Toxic element intake in young minke whales (1-15 years) significantly decreased with sampling years,
while that of over 16 year individuals was stable. These results can be interpreted as changes of feeding
environment in Antarctic minke whales in recent years. In the pollutant levels in Antarctic minke whales,
toxic and essential element levels, except for Fe, in Antarctic minke whales were considerably lower thanthose of cetaceans from the Northern Hemisphere. These element levels detected in livers of Antarctic
minke whales may not have any adverse effect on whale health.
KEY WORDS: ANTARCTIC MINKE WHALE; TRACE ELEMENT; BIOACCUMULATION, AGE
TREND, FOOD AVAILABILITYINTRODUCTION
In 1992, the International Whaling Commission (IWC) decided to establish a regular agenda item for research on
effects of environmental change on cetaceans in the Scientific Committee (SC) of IWC (IWC, 1993). At the
IWC/SC meeting in 1994, the Committee addressed: (1) global warming; (2) ozone depletion; (3) pollution; (4)direct and indirect fisheries; (5) noise; and (6) other human activities (e.g. tourism, coastal development) (IWC,1995). However, because of difficulty to conduct all topics simultaneously, it agreed to initially focus on two
specialized items, the relationships between chemical pollutants and cetaceans, and the potential ecological effects
of climate change and ozone depletion on cetaceans (IWC, 1999). Then, the Committee decided to hold twoworkshops (IWC, 1999). The JARPA was designed to cover these items by collecting related samples and datafrom the beginning of the program, in order to respond to a growing concern over environmental changes. Some
results on effects of environmental changes on cetaceans in JARPA surveys were reported in the JARPA review
meeting in 1997 (Government of Japan, 1995; Fujise, 1997).
We have monitored pollutants, such as trace elements and organochlorine compounds, in Antarctic minke
whales in the JARPA research. Trace elements include oxic elements, such as Hg, Cd, Pb and Ni (or nonessential
element), and essential elements, such as Cu, Zn, Fe and Mn. Toxic elements induced adverse effects for animals
and humans and indicate more persistence than essential elements. Essential elements are essential for survival
and health of animals and humans.
Fujise (1997), Watanabe et al. (1998) and Honda et al. (2006) reported that 'yearly changes of ageaccumulation patterns of hepatic Hg in Antarctic minke whales suggest possible environment changes such as
1changes of food availability.’ This hypothesis was also supported by the studies on biological parameters(Zenitani et al., 1997), body fatness and blubber thickness (Ohsumi et al., 1997) of Antarctic minke whales.
The object of this report is to monitor levels and behaviour of trace elements, especially toxic elements, in
Antarctic minke whales and to evaluate their health effects.

MATERIALS AND METHODS
Antarctic minke whales were collected from Areas IIIE (35-70E), IV (70-130E) and V (130E-170W), VIW(170W-145W), alternative years in JARPA. Liver samples of 1,056 (918 males and 138 females) Antarctic minke
whales from Areas IIIE, IV, V and VIW sampled during 1988/89 and 2004/05 were excised form the medial
region for trace element analysis (Table 1). All samples were stored in polyethylene bags at -20°C until analysis.
Examined temporal trends of trace element levels in age organization, four age groups, 1-15, 16-25 and over 26
years, were selected at random in each year. Sex differences were examined only in 1988/89 and 1998/99.
For the analysis of Hg, Cd, Pb, Ni, Cu, Zn, Fe and Mn, the tissues were homogenized and digested in
microwave (Milestone General: MLS 1200 mega) using nitric acid in a PTFE (Teflon) vessel (Okamoto, 1994).
Cd, Pb, Ni, Cu, Zn, Fe and Mn were measured by inductively coupled plasma atomic emission spectrometry(Seiko Instruments Inc., SPS 1700R) and Hg was measured by cold vapour / atomic absorption spectrometry(Nippon Instruments Co. RA-2A) using external standard method. Concentrations of liver are given on wet weightbasis. Accuracy and precision of the methods were confirmed using 'bovine liver' (BCR-CRM No. 185) and 'pig
kidney' (BCR-CRM No. 186). Chemical analyses were performed by the Miura Institute of Environmental
Science.
The differences between sexes and areas were assessed by Mann-Whitney U test and the relationships
between concentrations of trace elements and age were assessed by Spearman rank correlation (Zar, 1999). To
analyze factors for trace element levels in Antarctic minke whales, we used the stepwise multiple regression
analysis. These statistical analyses were executed by SPSS ver.11 for Windows (SPSS Co. Ltd.).

RESULTS AND DISCUSSION
Cd, Cu, Zn, Fe and Mn were detected in almost all of the liver samples of Antarctic minke whales and Hg was
detected, except for one animal. Pb and Ni concentrations in all the liver samples of Antarctic minke whales were
almost less than the lower level of determination limit. The ranges of concentrations for each element were, inμg/g
wet wt: Hg, <0.005-0.43; Cd, 0.089-66; Pb, <0.3-0.7; Ni, <0.1-0.3; Cu, 2.8-14; Zn, 18-103; Fe, 1.6- 11000; Mn,
1.4-7.4.
In general, no gender difference of most trace elements accumulation is observed in marine mammals(Law, 1995). Gender differences in trace element levels were confirmed using individuals taken from the Area V
in 1988/89 and 1998/99 (Table 2). Hepatic Fe and Zn concentrations of Antarctic minke whales in 1988/89 weresignificantly different between sexes. Hepatic Fe concentrations of males clearly increased with age and those of
females were not observed (Fig. 1a, 1b). In this paper, only male samples were used for the examinations to avoid
sex difference.
Factors for trace element levels in minke whales
A multiple regression analysis was done to determine the extent of effect of individual factors of sampling years,
age, sampling longitude and latitude (Table 3). For Hg and Cd, sampling year, age and longitude weresignificantly selected. Toxic element, such as Hg and Cd, levels are simply determined by food intake, food toxic
element levels and their turn over (Honda 1985; Law, 1995). On the other hand, essential element levels inanimals are maintained constant due to homeostasis and not relatively affected by several varying environments(Mertz, 1981). However, toxic and essential elements, except for Mn, were significantly selected with thesampling longitude, while not selected with the sampling latitude. It is suggested that longitude variation is more
important than latitude for spatial trend of trace element in Antarctic minke whales.

2

Toxic elements
Age trend
Figures 2a, 2b, 3a and 3b represents plots of hepatic Hg and Cd concentrations in males of Antarctic minke
whales taken from the Areas IV and V, versus their age. Table 4 shows significant correlation between hepatic Hgand Cd concentrations and age in males of Antarctic minke whales tested with Spearman rank test (p<0.05) in
Areas IIIE-VIW. In general, positive correlation was not observed Hg/Cd and age until 1993/94 season, but it wasobserved since then.
It has been reported that hepatic Hg and Cd levels increase with age in whales (Denton et al., 1980;
Honda et al., 1983; Mackey et al., 1996; Law, 1995). However, Honda et al. (1987) reported that ageaccumulation of hepatic Hg levels in Antarctic minke whales taken from the Antarctic during 1980 and 1985 was
not observed, because food intake of the young minke whales rapidly increased. Furthermore, Fujise (1997) and
Honda et al. (2006) reported that age-accumulation of the hepatic Hg concentrations in Antarctic minke whales
were clearly observed during 1988/89 and 1998/99. Honda et al. (2006) suggested that hepatic Hg levels in theyoung minke whales decreased due to the decrease of the food stock since middle 1980’s. Our result wasconsistent with the previous studies. And also, this hypothesis is supported by results in another study that Hg andCd levels in Antarctic krill from the Areas III-IV and V-VI are stable during 1988/89 and 1997/98 (Yasunaga etal., 2006).

Spatial trend
Plots of hepatic Hg and Cd concentrations in Antarctic minke whales (16-25 years) taken during 1995/96 and2002/03 against their sampling latitude are shown in Fig.4. Mature males which were from 16 to 25 years old
were used for statistical analysis to avoid influence of age and sex. Correlation between hepatic Hg (r=0.205,
p=0.028) and Cd (r=0.575, p<0.001) levels with sampling latitude were significantly observed by Spearman rank
test.
Toxic element levels in Antarctic minke whales are related to food intake and their toxic element levels.
Geographical differences of Cd and Hg levels in Antarctic krill, the stomach contents of Antarctic minke whales,
were not observed between Areas IIIE-IV and V-VIW (Yasunaga et al., 2006). Then, food intake of minke whales
taken from western (Area IIIE) would be lower than those from eastern (Area VIW). This is consistent with thereport that blubber thickness, as obesity index, of Antarctic minke whales from Areas IV and V became thicktoward East (Konishi et al., 2006). These reports suggest that feeding environment in eastern area would be better
than that in western area. On the other hand, Murase et al. (2006a, b) reported that biomass of Antarctic krill in
Area IV was higher than Area V, while the magnitude of interspecies competition of baleen whales in Area IV
was higher than the magnitude in Area V. This point should be investigated quantitatively in future to reveal thosephenomena.

Temporal trend
Plots of hepatic Hg and Cd concentrations in Antarctic minke whales in each age group, 1-15, 16-25 and over 26
years old, against their sampling year are shown in Fig.5. Results of simple linear regression analysis identified
the dependent variables as hepatic logarithm Hg and Cd concentrations and sampling year as independent variable
as shown in Table 5. Hepatic Hg and Cd levels decreased significantly in the youngest age group (1-15 years)
from Areas IV and V, hepatic Cd levels in middle age group (16-25 years) from Area IV and hepatic Hg levels in
the oldest age class (over 26 years) form Area IV. This result would mean that food intake of minke whales inlater stage of JARPA research would be lower than that in earlier stage from Areas IV and V. Furthermore, thistrend was mainly observed in youngest age class. It can be interpreted as changes of feeding environment in
Antarctic minke whales in recent years.

Essential elements
The Antarctic minke whale hepatic Mn and Fe shows correlation coefficient by Spearman rank test (Table 6).
Figure 6 shows the relationships between the hepatic Mn and Fe levels and age. Hepatic Mn and Fe levels in
Antarctic minke whales were affected with their age and sampling areas. Regression slopes of Mn with age among
Areas IIIE, IV, V and VIW were not significantly different, while those of Fe were significantly different among
Areas IIIE, IV, V and VIW, except for between Areas IV and VIW (ANCOVA, p<0.05). The difference is3

because hepatic Fe might be affected by food intake and physiological functions such as immunological system,
and requirement of hepatic Mn level in infant is characteristically higher than that in the following stages.
Figure 7 shows a plot of average of Zn levels in Antarctic minke whales versus the sampling year.
Hepatic Zn data from each sampling year were pooled as there were no age-accumulation observed. The temporalZn curve has cyclic ups and downs each 3-5 years. In mammals, Zn is related to the activity and stability of morethan 200 metallo-enzymes, so its physiological function is a complicated system. However, these functions wereindistinguishable in this study.
Copper levels in Antarctic minke whales were affected by sampling year, age and longitude. In marine
mammals, Cu levels in neonates and juvenile are higher than are those of mature individuals (Honda 1985; Fujise,1987). Copper levels in animals are affected by metabolic interactions with other essential elements, such as Cd,
Fe and Zn, further complicating the interpretation (Davis and Mertz, 1987).
Comparison of trace element levels in baleen whales
Table 7 and Fig. 8 show the trace element levels in livers of whales around the world as previously reported forcomparison with our data.
Hepatic Hg levels of Antarctic minke whales were one order of magnitude lower than those of common
minke, sei and Bryde’s whales from the western North Pacific. In general, it is known that hepatic Hg levels ofbaleen whales are lower than those of tooth whales (Honda et al., 1983; Law, 1995). Hepatic Cd levels areconstant in baleen and tooth whales in the world and Cd levels of Antarctic minke whales are classified intohigher categories in analogue with sei and sperm whales from the western North Pacific and narwhals from thenear Greenland. Hepatic Pb and Ni levels of the whales, except for striped dolphins, were almost less than thelower limit of determination level or close to these.
Hepatic levels of essential elements, such as Mn, Cu and Zn, of Antarctic minke whales are comparable
to those of other baleen and tooth whales in the Northern Hemisphere. However, hepatic Fe levels of Antarctic
minke whales were one order of magnitude higher than those of other whales in the Northern Hemisphere. Higher
Fe levels may be caused by their physiological functions, because dissolved iron is extremely low in the surface
water of Antarctic Ocean (Martin et al., 1991)
Therefore, trace element levels, except for Fe, in Antarctic minke whales were extremely orcomparatively lower than those of cetaceans from Northern Hemisphere. Then, these element levels measured inlivers of Antarctic minke whales may not have any adverse effect on whale health.

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to Review Data and Results form the Japanese Whale Research Program under Special Permit in the
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krill standing stock by three baleen whale species (Antarctic minke, humpback and fin whales) in Areas IV
and V using JARPA data. Paper SC/D06/J22 presented to the IWC Sponsored Meeting to Review Data andResults form the Japanese Whale Research Program under Special Permit in the Antarctic (JARPA)(JARPA Review Meeting), December 2006 (unpublished).
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Antarctic minke whale and its yearly change. Paper SC/M97/18 presented to the IWC Intersessional
Working Group to Review Data and Results from Special Permit Research on Minke whales in the
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mercury accumulation in Antarctic minke whale collected in 1980-82 and 1984-86. Nippon Suisan
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in Areas III, IV, V and VI from Antarctic Ocean during 1989-1999. Paper SC/D06/J27 presented to the
IWC Sponsored Meeting to Review Data and Results form the Japanese Whale Research Program underSpecial Permit in the Antarctic (JARPA) (JARPA Review Meeting), December 2006 (unpublished)
Zar, J.H. 1999 Biostatistical analysis, 4th ed., Prentice Hall, New Jersey, USA, 663pp.
5

Zenitani, R., Fujise, Y. and Kato. H. 1997. Biological parameters of Southern minke whales based on materials
collected by the JARPA survey under special permit in 1987/88 to 1995/96. Paper SC/M97/12 presented to
the IWC Intersessional Working Group to Review Data and Results from Special Permit Research on
Minke whales in the Antarctic, May 1997 (unpublished). 19pp.

6

Table 1 Description of Antarctic minke whales using for trace element analysis
Year
Area
n (sex)Body length (m)1988/89
Area V
68M
7.91
Area V
76F
8.22
1989/90
Area IV
100M
8.40
1990/91
Area V36M
8.47
1991/92
Area IV
36M
8.42
1992/93
Area V
36M
8.54
1993/94
Area IV
36M
8.44
1994/95
Area V
49M
8.12
100M
8.15
1995/96
Areas IIIE, IV
1996/97
Areas V, VIW
75M
7.89
1997/98
Areas IIIE, IV
75M
7.81
1998/99
Areas V, VIW
108M
7.58
Areas V, VIW
62F
7.17
1999/00
Areas IIIE, IV
39M
7.93
2000/01
Areas V, VIW
40M
7.73
2001/02
Areas IIIE, IV
40M
7.86
2002/03
Areas V, VIW
40M
7.79
2003/04
Area V
20M
7.95
2004/05
Area V
20M
7.91

7

8

Table 2. Hepatic trace element concentrations (μｇ/g wet wt) and sex difference of Antarctic minke whales (over 16 years) in 1988/89 and 1998/99.
Cd
Hg
Cu
Zn
Fe
Mn
5.2
1988/89
males
Ave.
0.078
16
40
2407
3.2
Range ( 0.023 - 0.23
) ( 5.3 - 32 ) (4 - 7.4 ) ( 31 - 52 ) ( 798 - 6170 ) ( 1.8 - 4.2
n
16
16
16
16
16
16
females
Ave.
0.11
20
5.4
52
361
3.5
Range ( 0.044 - 0.27
) ( 8.3 - 63 ) ( 4.4 - 9.3 ) ( 37 - 103 ) ( 41 - 2630 ) ( 2.2 - 4.9
n
22
22
22
22
22
22
p
0.060
0.162
0.356
0.001
<0.001
0.651
Significant difference*****
1998/99
males
Ave.
0.093
2550
18
5.1
46
3.1
Range ( 0.010 - 0.43
) ( 5.5 - 51 ) ( 3.5 - 11 ) ( 30 - 70 ) ( 130 - 6800 ) ( 1.7 - 4.6
n
40
40
40
40
40
40
females
Ave.
0.082
20
5.2
54
608
2.8
Range ( 0.043 - 0.16
) ( 13 - 45 ) ( 3.7 - 10 ) ( 33 - 99 ) ( 23 - 1900 ) ( 2.0 - 4.9
n
13
13
13
13
13
13
p
0.901
0.443
0.901
0.100
<0.0010.181***
Significant difference*: p<0.05, **: p<0.01, ***: p<0.001

)

)

)

)

Table 3 The results of multiple regression cofficients.
LN (Hg conc.)
LN (Cd conc.)
Constant
B±ＳＥ
47.812±9.528
80.060±12.350
P value<0.001***<0.001***
Year (1988-2004)
B±ＳＥ-0.026±0.005-0.039±0.006
P value<0.001***<0.001***Age
B±ＳＥ0.025±0.002
0.040±0.002
P value<0.001***<0.001***Longitude (E+W)
B±ＳＥ
0.002±0.000
0.004±0.001
P value<0.001***<0.001***
Latitude (S)B±ＳＥ-0.003±0.008-0.011±0.010
P value
0.747
0.280*: p <0.05, **: p <0.01, ***: p <0.001

LN (Cu conc.)
20.186±3.183<0.001***-0.009±0.002<0.001***-0.002±0.001
0.009**
0.0004±0.000
0.026*-0.006±0.003
0.028

LN (Zn conc.)
16.608±3.343<0.001***-0.006±0.002<0.001***-0.000001±0.001
0.999
0.001±0.000<0.001***-0.005±0.003
0.106

LN (Fe conc.)-10.692±21.752
0.623
0.008±0.011
0.448
0.078±0.004<0.001***-0.005±0.001<0.001***-0.002±0.018
0.909

LN (Mn conc.)-0.156±3.905
0.968
0.001±0.002
0.560-0.006±0.001<0.001***0.0006±0.000<0.001***-0.013±0.003<0.001***

9

Table 4 Significant correlationships between age and hepatic Hg and Cd concentrations in Antarctic minke
whales tested with Spearman rank test.
Cd
Year
Hg
Area III
1988/89
1989/90
1990/91
1991/92
1992/93
1993/94
1994/95
1995/96
1996/97
1997/98
1998/99
1999/00
2000/01
2001/02
2002/03
2003/04
2004/05

r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p
r
p

Area IV

Area V
0.410**
0.002

Area VI

Area III

0.161
0.110

Area IV

0.533**
0.001-0.0560.7440

0.306
0.069
0.000
0.998

0.081
0.637

0.190
0.266

0.220
0.198
0.489***<0.0010.516**
0.004

0.779***<0.0010.789***<0.0010.552*
0.014

0.644**
0.003
0.770***<0.0010.737***<0.0010.650***<0.0010.654**
0.002

0.545*
0.016

0.755***<0.001

0.543*
0.013

0.497*
0.026

0.715***<0.001

0.583**
0.007

0.677***<0.0010.814***<0.001

0.365
0.124

0.846***<0.0010.623***<0.0010.610**
0.00100.386*
0.018

0.532*
0.016
0.648**
0.002

0.487***<0.0010.430**
0.006

0.550**
0.004
0.620***<0.0010.892***<0.0010.453**
0.001

0.438***<0.0010.466*
0.012

0.647***<0.001

Area VI

0.222*
0.026
0.299
0.076

0.468**
0.009

Area V
0.565***<0.0010.515*
0.020
0.595**
0.006

0.555*
0.006*: p <0.05, **: p <0.01, ***: p <0.001

10

Table 5 Simple linear regression analysis of logarithm Hg and Cd concentrations in Antarctic minke whales
from Areas V and VI with their sampling year
Area IV
Area V
LN_Hg
LN_Cd
LN_Hg
LN_Cd
p
<0.001***<0.001***0.01*
0.005**-2-2-2
1-15 years
Year-8.350×10 -2-6.559×10-2.804×10-4.227×10
Constant
163.3670
132.81252.91786.308p
0.153
0.016*
0.118
0.6580
16-25 years
Year-3.823×10 -2
Constant
78.583p
0.049*
0.717
0.209
0.662
-2
over 26 yearsYear-2.485×10
Constant
46.7820*: p <0.05, **: p <0.01, ***: p <0.001

Table 6 Correlationships between the hepatic trace element concentrations and age in Antarctic
minke whales during 1988/89 and 2004/05 using Spearman rank correlation test.
Area IIIArea IV
Area V
Area VIr-0.365-0.246-0.317-0.290Mnp<0.001***<0.001***<0.001***0.001**
n
106
327
316
117
r
0.804
0.642
0.522
0.801
Fe
p
<0.001***<0.001***<0.001***<0.001***
n
106
327
316
117

*: p <0.05, **: p <0.01, ***: p <0.001

11

12

Table 7. Trace element concentrations (μg/g wet wt) in the liver of cetaceans.
Pb
Hg
Cd
SpeciesnNi
Baleen whales
Antarctic minke
0.068
0.4
12
1056
0.2
whale
( <0.005 - 0.43 ) ( 0.089 - 66 ) ( <0.3 - 0.7 ) ( <0.1 - 0.3
Common minke
0.65
0.5
738
2.6
0.2
whale
( 0.001 - 4.3 ) ( 0.010 - 9.5 ) ( <0.3 - 2.0 ) ( <0.1 - 0.4
Common minke
0.39*
17
0.90*
whale
( 0.14 - 2.68 ) ( 0.50 - 1.45 ) (
) (
<0.3
0.18
Bryde's whale
143
3.1
<0.1
) (
( 0.011 - 1.1 ) ( 0.030 - 9.0 ) (
0.43
<0.3
Sei whale
39
11
<0.1
( 0.07 - 1.6 ) ( 3.1 - 25 ) () (0.55
fin whale11( 0.16 - 1.4 ) (
)(
) (
0.55
fin whale5( 0.39 - 0.82 ) (
)(
) (
0.07
0.04
Bowhead whale20( 0.02 - 0.11 ) () ( <0.03 - 0.04 ) (Toothed whales
62<0.3
Sperm whale
13
14
<0.1
( 3.2 - 250 ) ( 4.0 - 31 ) (
) (
1.77*
beluga40
2.21*) (( 0.07 - 30.8 ) ( <0.015 - 8.54 ) (
5.26*
10.8*
Narwhal48-90) (( <0.005 - 42.8 ) ( <0.015 - 73.7 ) (
169*
1.3*
Striped dolphin
37-46
(
)(
)(
) (
205
6.26
0.22
0.22
Striped dolphin
20-30( 1.7 - 485 ) ( 0.04 - 11.1 ) ( 0.03 - 0.64 ) ( 0.1 - 0.5
20.0
7.81
Dall's porpoise
26M( 6.52 - 48.7 ) ( 2.62 - 17.8 ) () (*: Median

Zn

Cu

Fe

Mn

4.4
) ( 2.6 - 1112
) ( 5.6 - 50
)(

)(

)(

-

)(

)(

)(
4.9
) ( 2.8 - 8.0 ) (34
22 - 6132
610
25 - 39 ) ( 33 - 1700
28.4*)(
) ( 22 - 45.2 ) (35.9*)() ( 13.3 - 67.7 ) (
6.3*
32*
)(
)(
)(
8.09
44.5
215
) ( 3.57 - 15.2 ) ( 27 - 109 ) ( 55.8 - 95.5
7.42
43.2
254
) ( 1.29 - 17.4 ) ( 32 - 53.5 ) ( 106 - 456
3.3) ( 2.1 - 5.1 ) (Area(References)

1988-2005 Antarctic
3.5
1.4 - 7.4 )(This study)
1994-2002 NW Pacific3.4
1.1 - 9.5 )(In preparation)
1980 W Greenland)(Hansen et al. , 1990)
2000-2 NW Pacific2.4
1.3 - 5.3 )(In preparation)
2002 NW Pacific2.2
1.5 - 3.2 )(In preparation)
1983-4 Spain (Factory))()()(Sanpera et al. , 1993)
1986
Iceland (Factory))()()(Sanpera et al. , 1993)
1994
Alaska (Barrow)
0.93
700) ( 135 - 2740 ) ( 0.4 - 2.0 )(Krone et al. , 1999)

43
1400
18 - 103 ) ( 1.6 - 11000 ) (41368) ( 21 - 82 ) ( 2.5 - 4108 ) (34.5*)() ( 26.4 - 48.0 ) (36275) ( 21 - 54 ) ( 2.6 - 2000 ) (37162) ( 22 - 68 ) ( 31 - 500 ) (5.2) ( 2.8 - 14
7.0
) ( 2.0 - 34

year

2000-2 NW Pacific0.7) ( 0.40 - 1.0 )(In preparation)
1984-5 W Greenland)()(Hansen et al. , 1990)
1984-5 W Greenland)()(Hansen et al. , 1990)
1987-94 Italy)()(Monaci et al. , 1998)
3.18
1978-80 NW Pacific) ( 1.30 - 6.71 )(Honda et al. , 1998)
6.31
1982-84 NW Pacific) ( 4.03 - 7.70 )(Fujise, 1987)

70

0.20

0.10

0.00

60
50
40
30
20
10
0

0

10

20
30
Age (year)

40

50

10

20
30
Age (year)

40

0.2
0.1

60
50
40
30
20
0

0

10

20
30
Age (year)

40

50

6
4
2
10

20
30
Age (year)

40

50

12
(98/99)

10
0.0

8

0

Cu conc. (ppm wet)13

Cd conc. (ppm wet)

0.3

10

50

70
(98/99)(88/89)

12

0
0

0.4
Hg conc. (ppm wet)14

(88/89)Cu conc. (ppm wet)

(88/89)

Cd conc. (ppm wet)Hg conc. (ppm wet)

0.30

(98/99)

10
8
6
4
2
0

0

10

20
30
Age (year)

40

50

0

10

20
30
Age (year)

40

50

Fig. 1a. Relationships between age and trace element concentrations (μg/g wet wt.) in the liver of Antarctic minke whales (male=〇, female=●)from Antarctic Ocean Area V.

8000

100
80
60
40
20
0

6000
4000
2000

10

20
30
Age (year)

40

50

0

120

10

20
30
Age (year)

40

14

60
40
20
0

6000
4000
2000

10

20
30
Age (year)

40

50

10

20
30
Age (year)

40

50(98/99)
6.0
4.0
2.0
0.0

0
0

2.0

0

Mn conc. (ppm wet)

80

4.0

8.0
(98/99)Fe conc. (ppm wet)

100

6.0

50

8000
(98/99)(88/89)0.0

00

Zn conc. (ppm wet)

8.0

(88/89)Mn conc. (ppm wet)

(88/89)Fe conc. (ppm wet)

Zn conc. (ppm wet)

120

0

10

20
30
Age (year)

40

50

0

10

20
30
Age (year)

40

50

Fig. 1b. Relationships between age and trace element concentrations (μg/g wet wt.) in the liver of Antarctic minke whales (male=〇, female=●)from Antarctic Ocean Area V.

0.30

0.20

0.10

0.00

0.10

20
30
Age (year)

40

50

10

20
30
Age (year)

0.30

0.20

0.10

0.00

40

20
30
Age (year)

0.30

40

0.10

10

20
30
Age (year)

0.30

0.20

0.10

0.00

40

10

20
30
Age (year)

40

50

40

50

(98/99)

0.20

0.10

50

0

10

20
30
Age (year)

0.30(02/03)

0.20

0.10

0.00
0

20
30
Age (year)

0.00
0(00/01)10

0.30(96/97)

0.20

50

0.10

0

Hg conc. (ppm wet)

10

0.20

50

0.00
0

Hg conc. (ppm wet)15

Hg conc. (ppm wet)

(94/95)(92/93)0.00
0Hg conc. (ppm wet)

10

0.30
Hg conc. (ppm wet)

0.20

0.00
0

Hg conc. (ppm wet)

0.30

(90/91)
Hg conc. (ppm wet)

(88/89)Hg conc. (ppm wet)Hg conc. (ppm wet)

0.30

40

50

(04/05)

0.20

0.10

0.00
0

10

20
30
Age (year)

40

50

0

10

20
30
Age (year)

40

50

Fig. 2a Yearly Relationships between age and hepatic Hg concentrations of Antarctic minke whales (males) from the Antarctic Area V.

0.30

0.20

0.10

0.00

0.10

20
30
Age (year)

40

50

10

20
30
Age (year)

0.30

0.20

0.10

0.00

40

10

20
30
Age (year)

0.30

40

0.10

0.00

20
30
Age (year)40

50(99/00)

0.20

0.10

0.00
10

20
30
Age (year)

0.30

0.20

10

0.30

0.10

0

(01/02)0.10

0(97/98)

0.20

50

0.20

50

0.00
0

Hg conc. (ppm wet)16

Hg conc. (ppm wet)

(95/96)(93/94)0.00
0

Hg conc. (ppm wet)

10

0.30
Hg conc. (ppm wet)

0.20

0.00
0

Hg conc. (ppm wet)

0.30

(91/92)
Hg conc. (ppm wet)

(89/90)Hg conc. (ppm wet)Hg conc. (ppm wet)

0.30

40

50

0

10

20
30
Age (year)40

50(03/04)

0.20

0.10

0.00
0

10

20
30
Age (year)

40

50

0

10

20
30
Age (year)

40

50

Fig. 2b Yearly relationships between age and hepatic Hg concentrations of Antarctic minke whales (males) from the Antarctic Area IV

45
40
35
30
25
20
15
10
5
0

40

50

0

Cd conc. (ppm wet)

(94/95)102030
Age (year)

45
40
35
30
25
20
15
10
5.0
0.00

40

50

Cd conc. (ppm wet)
10

20
30
Age (year)

40

50

20
30
Age (year)

45
40
35
30
25
20
15
10
5
0

40

10

20
30
Age (year)

45
40
35
30
25
20
15
10
5.0
0.00

40

10

20
30
Age (year)40(92/93)

0

50

10

20
30
Age (year)

45
40
35
30
25
20
15
10
5
0

50

40

50

(98/99)0(02/03)

0

45
40
35
30
25
20
15
10
5
0

50

(96/97)0(00/01)

0

10

Cd conc. (ppm wet)20
30
Age (year)(90/91)

Cd conc. (ppm wet)100

Cd conc. (ppm wet)17

Cd conc. (ppm wet)

0

45
40
35
30
25
20
15
10
5
0

Cd conc. (ppm wet)

(88/89)
Cd conc. (ppm wet)

Cd conc. (ppm wet)

45
40
35
30
25
20
15
10
5
0

10

20
30
Age (year)

45.0
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0

40

50

(04/05)

0

10

20
30
Age (year)

40

50

Fig. 3a Yearly relationships between age and hepatic Cd concentrations of Antarctic minke whales (males) from the Antarctic Area V.

20
30
Age (year)

45
40
35
30
25
20
15
10
5
0

40

50

0

Cd conc. (ppm wet)

(95/96)102030
Age (year)

45
40
35
30
25
20
15
10
5.0
0.00

40

50

Cd conc. (ppm wet)
10

20
30
Age (year)

40

50

10

20
30
Age (year)

45
40
35
30
25
20
15
10
5
0

40

50

10

20
30
Age (year)

45.0
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0

40

50

45
40
35
30
25
20
15
10
5
0

(93/94)0(97/98)0(01/02)0(91/92)

Cd conc. (ppm wet)100

Cd conc. (ppm wet)18

Cd conc. (ppm wet)

0

45
40
35
30
25
20
15
10
5
0

Cd conc. (ppm wet)

(89/90)
Cd conc. (ppm wet)

Cd conc. (ppm wet)

45
40
35
30
25
20
15
10
5
0

10

20
30
Age (year)

45
40
35
30
25
20
15
10
5.0
0.00

40

50

(99/00)

0

10

20
30
Age (year)40

50(03/04)

0

10

20
30
Age (year)

40

50

Fig. 3b Yearly relationships between age and hepatic Cd concentrations of Antarctic minke whales (males) from the Antarctic Area IV

0.300Hg conc. (ppm wet)

0.250

Hg

0.200
y = 0.0002x + 0.0559
2
R = 0.0826

0.150
0.100
0.050
0.000

30E
30

60E
60

90E
90

120E
150E
120
150
Sampling
longitude

180E
180

150W
210

240

120E
150E
180E
120
150
180
Sampling longitude

150W
210

240

75

Cd conc. (ppm wet)Cd50

y = 0.0784x + 4.769
R2 = 0.2676

25

0

30E
30

60E
60

90E
90

Fig. 4 Relatioships between hepatic Hg and Cd concentrations in Antarctic minke
whales (16-25 years old) taken during 1995/96 and 2002/03 and their sampling
longitude

19

0.10

0.05

0.00

0.15

0.10

0.05

0.00

1985

1990

1995
Year

2000

2005

30

Area IIIE

1990

1995
Year

2000

15

20

10
5

20
15
10

1990

1995
Year

2000

2005

1985

1995
Year

2000

2000

2005

0.05

1985

1995
Year

2000

2005

1995
Year

2000

2005

Area VIW
25

20
15
10

1985

1990

30

Area V

20
15
10
5

0
1995
Year

0.10

2005

5

1990

0.15

0.00
1990

25

0

1985

0.05

30

Area IV

5

0

0.10

1985

Cd conc. (ppm wet)

20

Area VIW

0.15

2005

25
Cd conc. (ppm wet)

25

0.20

Area V

0.00

1985

30

Cd conc. (ppm wet)Hg conc. (ppm wet)Hg conc. (ppm wet)Hg conc. (ppm wet)

0.15

0.20

Area IV

Hg conc. (ppm wet)

0.20

Area IIIE

Cd conc. (ppm wet)

0.20

0
1990

1995
Year

2000

2005

1985

Fig. 5 Relationships between average concentrations of hepatic Hg and Cd in each year goup (1-15, 16-25, over 26 years) of
Antarctic minke whalse from Area IIIE, IV, V and VIW and their sampling years

1990: 1-15 years: 16-25 years: over26 years

Fe
100

10

Fe
100

10

20

30
Age (year)

40

50

60

1000

Fe
100

10

20

30
Age (year)

40

50

60

Mn
Fe
100

10

1
0

Area VIW

Mn

10

1
0

10000

Area V

1000

Mn

10

1

10000

Area IV

1000

Mn
Conc. (ppm wt)

Conc. (ppm wt)

1000

10000

Conc. (ppm wt)

Area IIIE

Conc. (ppm wt)

10000

1
0

10

20

30

40

50

60

0

10

Age (year)

Fig. 6 Relationships between hepatic Mn and Fe concentrations and age of Antarctic minke whales from Areas IIIE, IV, V and VIW

2030
Age (year)

40

50

60

21

60

Area IIIArea IV

50

Area V
Area VI

Conc. (ppm wet)

40
30
20
10
0
'88/89 '90/91 '92/93 '94/95 '96/97 '98/99 '00/01 '02/03 '04/05'89/90 '91/92 '93/94 '95/96 '97/98 '99/00 '01/02 '03/04
Year

Fig. 7 Relationships between hepatic Zn levels and sampling year in Antarctic minke whales
from Area IIIE, IV, V and VW

22

20

NANANANA
Sei whale 2)

Bowhead whale

Common minke whale 3)

5)

5.26

Common minke whale 2)

169

Dall’s porpoise 8)
62

205

NANA NA23

NANANA

Beluga3)

Narwhal3)

NA NA
Striped dolphin 6)

Bryde’s whale 2)
Sperm whale 2)(ppm wet wt)

5

Striped dolphin 7)
1418

NANANANANAFin whale 4)

4
3
2
1
0

Mn
Cu
Fe
(x2) (x200) (x4)

Zn
(x10)

Cd Hg
(x4) (x1)

Antarctic minke whale 1)

Fig. 8. Trace element levels in livers of Cetaceans.
1) This study (2006); 2) In preparation; 3) Hansen et al. (1990); 4) Sampera et al. （1993）; 5) Krone et al. (1999) ; 6) Monaci et al. (1998); 7) Honda et al. (1983);
8) Fujise (1987)
NA: Not Analysis