SC/F14/J24

Pattern of organochlorine accumulation in the
Antarctic minke whale based on JARPAII data
GENTA YASUNAGA, TAKEHARU BANDO AND YOSHIHIRO FUJISEThe Institute of Cetacean Research, 4-5 Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan.
Contact e-mail:yasunaga@cetacean.jp

ABSTRACT
Concentrations of persistent organochlorins were determined in the blubber of 5 mature male
(21-25 years old) Antarctic minke whales from Antarctic Area V sampled by JARPAII in
2010/11. For comparison, blubber from 40 whales sampled by JARPA surveys in the period
from 1988/1989 to 2004/2005, were used. In 2010/11 mean concentrations of HCB (140 ng/g fatwt.) were the highest followed by DDTs (100 ng/g fat wt.), PCBs (28 ng/g fat wt.), CHLs (25ng/g fat wt.), and HCHs (0.8 ng/g fat wt.). Levels of DDTs, HCHs, HCB and CHLs in Area V
decreased significantly with year, while the yearly trend of PCBs did not change significantly.
HCHs levels in minke whales in 2010/2011 were similar to those in the JARPA period from
1996/1997 to 2004/2005 however they were lower than those in the JARPA period from 1988/89
to 1996/1997. These results suggested that levels of HCHs in the Antarctic Ocean have varied
from slightly decreasing to a steady state in the middle 1990’s.
KEYWORDS: ANTARCTIC MINKE WHALE; ORGANOCHLORINES; MONITORING;TREND

INTRODUCTION
In the 1995/96 research plan of Japan's Whale Research Program under Special Permit in the Antarctic(JARPA) the following objective was added, ‘Elucidation of the effect of environmental change on
cetaceans’ (Government of Japan, 1995). This object was added in response to resolutions adopted by theCommission on research on the environmental and whale stocks and on the promotion of research on theconservation of large whales (IWC, 1995). Given this, the Scientific Committee held two specialized
Workshops, one relating to chemical pollutants and cetaceans, and the other on the potential ecologicaleffects on cetaceans of climate change and ozone depletion (IWC, 1999). Monitoring of pollutants inbaleen whales and the ecosystem was then added as a part of first objective of JARPAII (Pastene et al.,2014).
Organochlorines (OCs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethanes
and metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB) and
chlordane compounds (CHLs), are man-made chemicals that are persistent in the environment.
Particularly PCBs, DDTs and its metabolites concentrate in animal bodies through food webs. Whales arein a high position in the food web of the ocean thus they may be suitable as monitors of pollutant levels
and their adverse effects (Tanabe et al., 1986; O’Shea and Brownell, 1994). For this reason, we have been
continuing to monitor OCs levels in blubber of Antarctic minke whale (Balaenoptera bonaerensis) since
the beginning of the JARPA research.
Aono et al. (1996) reported that PCBs residue levels in Antarctic minke whales increased between the
1984/85 and 1992/93 seasons, implying continuous discharge of PCBs in the southern hemisphere.
Furthermore, Yasunaga et al., (2006) reported in the final JARPA review in 2006 that PCBs, DDTs, HCB
and CHLs levels in minke whales in a period from 1988/89 to 2004/2005 extremely slowly decreased or
maintained a steady state, while those of HCHs were drastically decrease in the period.
The objective of the pollution study in the JARPAII is to continuously monitor levels and behavior of
OCs in minke whales. However, most of samples for this study since 2005/2006 were lost after the 2011
earthquake and tsunami (see IWC, 2012). Therefore, the limited number of samples that were not affectedby the disaster in 2010/2011 were compared with the previous JARPA data during a period from1

1988/1989 and 2004/2005, so that recent trend of OCs levels in minke whales could be examined.

MATERIALS AND METHODS
Materials
In this study, concentrations of PCBs, DDTs, HCHs, HCB and CHLs in the blubber samples of 5 minke
whales (mature males: 21-25 years) taken from the Antarctic Area V in 2010/2011 were determined. The
average body length was 8.58 m (range: 8.31 -8.78 m). In the field, blubber samples were collected, andstored at –20°C until analysis.
Laboratory analysis
OCs were determined by a GC-ECD (Hewlett Packard 5890 Series) and by GC-MS (JEOL Ltd., JMS700; JMS-SX102A). Chemical analysis of the OCs was carried out using the standard method describedby the Environmental Agency of Japan, with some modifications (Japan Environmental Agency, 1998).
Concentrations of OCs were expressed on a fat weight basis. Accuracy and precision of the methods wereconfirmed using 'Organics in cod liver oil' (NIST 1588a). Chemical analyses were performed by theMiura Institute of Environmental Science.
Statistical analysis
Temporal trends of OCs levels in blubber of minke whales were assessed by simple linear regression
analysis (Zar, 1999). In the regression analysis, OCs levels in minke whales were logarithmicallyconverted, because distribution of persistent OCs levels in biota is skewed to a higher order. A p value ofless than 0.05 was used as the criterion for statistical significance. These statistical analyses were
executed by PASW Statics 17.0 for Windows (SPSS Co. Ltd.).

RESULTS
Table 1 shows the concentrations of OCs in blubber in minke whales from Area V in 2010/2011. The
ranges of concentrations for each compound were, in ng/g fat wt.: PCBs, 21-43; DDTs, 81-160; HCHs,<0.2-0.8; HCB, 110-190; CHLs, 19-40. The patterns were in the order of HCB> DDTs> PCBs> CHLs >HCHs.
For comparing those in this study, organoclorines levels in minke whales in the JARPA period from1988/1989 to 2004/2005 are shown in Table 1. Fig. 2 shows plots of OCs levels in blubber of minke
whales from Area V from 1988/89 to 2010/11. Table 2 shows a simple linear correlation coefficients andprobability between year and log OCs concentrations in blubber from Area V (p<0.05). Levels of DDTs,
HCHs, HCB and CHLs in Area V significantly decreased with year, while PCBs did not show asignificant yearly trend. Fig. 3 shows OCs standardized with respect to PCBs, which are stable in theenvironment as well as animal body. In addition, PCBs have declined extremely slowly in the open ocean
and the Antarctic (Tanabe et al., 2003) and the influence of changes in the body fat is nullified bystandardization with PCBs. HCHs/PCBs ratio decreased by a factor of about ten in a span of 22 years in
Area V, while temporal trends of DDTs/PCBs, HCB/PCBs and CHLs/PCB were stable.

DISCUSSIONThe OCs levels of minke whales in this study are first compared to those of the common minke whales
taken from the northern hemisphere in the 1990's. Mean PCBs level of Antarctic minke whales (28 ng/g)
was two orders of magnitude lower than those of common minke whales in the western North Pacific(Aono et al., 1997: 3,168 ng/g). Mean DDTs, HCHs and CHLs levels of Antarctic minke whales (100ng/g, 0.8 ng/g, 25 ng/g, respectively) were one order of magnitude lower than those of common minke
whales in the western North Pacific (Aono et al., 1997: 2,297 ng/g, 446 ng/g, 595 ng/g, respectively). On
the other hand, mean HCB level of Antarctic minke whales (140 ng/g) was comparable to those ofcommon minke whales in the western North Pacific (Aono et al., 1997: 189 ng/g). Therefore the present
study confirms that the accumulation of PCB and most organochlorine pesticides in Antarctic minke
whales from the Antarctic Ocean are lower than those in common minke whales from the western North
Pacific.
All simple linear analyses (Table 2) for temporal trend of OCs in the Antarctic minke whales during theperiod from 1988/1989 to 2010/11 show OCs, except for PCBs, slightly decreased in the period.
Yasunaga et al. (2006) reported PCB levels in minke whales during the period from 1988/1989 to
2004/05 significantly decreased. Aono et al. (1997) reported that DDTs, CHLs, HCHs and HCB levels inblubber of the Antarctic minke whales taken from area V were comparable or slightly decreasing during

2the period from 1984/85 to 1992/93, while those of PCBs were likely to increase during a period of
1984/85 and 1990/92 and showed slightly decrease in the 1992/93 samples. Tanabe et al. (1999) analyzed
those samples up to the 1994/95 season, and reported that DDTs, CHLs, HCHs and HCB levels in
Antarctic minke whales in 1994/95 samples were generally within the same range as previous results,
while PCBs levels in 1994/95 samples were higher than those of samples during the period from 1984/85
to 1992/93. Our results of DDTs, CHLs, HCHs and HCB in the Area V were consistent with those of
Aono et al. (1997) and Tanabe et al. (1999), while our results for PCBs in the Area V were inconsistent
with their results. Aono et al. (1997) and Tanabe et al. (1999) used pooled data for the male minke whales
less than 25 years old, while the present study used the 20-25 year old males to avoid sex and aging
effects. The present study provides more accurate estimations for the temporal trend of OCs in the
Antarctic minke whales than those of Aono et al. (1997) and Tanabe et al. (1999).
Figure 3 shows organochlorine pesticides standardized with respect to PCBs, which are stable in theenvironment as well as animal bodies. In addition, PCBs have declined slowly in the open ocean and theAntarctic (Aono et al., 1997; Tanabe et al., 2003) and the influence of changes in the body fat is nullified
by standardization with PCBs. HCHs/PCBs ratio decreased by a factor of about ten in a span of 16 years
in both Areas IV and V, while temporal trends of DDTs/PCBs, HCB/PCBs and CHLs/PCB were stable.
These results indicated that PCBs, DDTs, HCB and CHLs levels in the Antarctic minke whales were
unchanged or slightly decreased in Area V during the research period. However, only HCHs levels clearlydecreased. The increase of OCs in the Antarctic environment and Antarctic minke whales observed in the
1980s appears to have ended in the 1990s. Organochlorine levels in ocean are affected by historical usage
and their physicochemical properties. About 10 Mt of HCHs have been released in the environment,
especially in the northern hemisphere (Li, 1999). Emission of HCHs increased steadily after theirintroduction in the 1940s until they reached a peak in the early 1970s in northern hemisphere (Li and
Macdonald, 2005). However, the usage history is similar to other OCs, because organochlorine levels
generally declined in the 1970s and leveled off in the 1980s as several bans were enforced in developed
countries (Weber and Goerke, 2003).
HCHs/PCB ratios of Antarctic minke whales in Area V for 22 years decreased by about 15 %, while
ratios of DDTs, HCB and CHLs to PCB concentrations of were stable. The decreasing ratios correspondto 6 years as the half-life of HCHs/PCB in the whales. However, HCHs levels in minke whales in2010/2011 were similar those in later stage of JARPA (1996/1997-2004/2005). This could suggest atendency for background levels of HCHs in Antarctic Ocean to have varied from slightly decreasing to asteady state since middle 1990’s.

ACKNOWLEDGMENTS
We thank L.A. Pastene of the Institute of Cetacean Research and S. Tanabe of Ehime University for
helpful suggestions and criticism on the manuscript.

REFERENCES
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whale (Balaenoptera acutorostrata) and their prey species from the Antarctic and the North Pacific.
Environ. Pollut. 98: 81-9.
Government of Japan. 1995. The 1995/96 research plan of Japanese whale research programme under
special permit in the Antarctic. Paper SC/47/SH3 presented to the IWC Scientific Committee, May 1995
(unpublished). 8pp.
International Whaling Commission. 1995. Report of the Scientific Committee. Rep. int. Whal. Commn.
45:53-103.
International Whaling Commission. 1999. Report of the workshop on chemical pollution and cetaceans. J.
Cetacean Res. Manage. (special issue) 1:1-42.
International Whaling Commission. 2012. Report of the Scientific Committee. Annex P1. Effect of the
March 11th earthquake and tsunami on JARPAII/JARPNII data and samples. J. Cetacean Res. Manage.
(Suppl.) 13:308-9.
Japan Environmental Agency. 1998. Analytical Manual for Dioxins in Soils. Tokyo, Japan (in Japanese;www.env.go.jp/chemi/dioxin/dojo-manual.pdf).

3

Li, Y.F. 1999. Global technical hexachlorocyclohexane usage and its contamination consequences inenvironment: from 1948 to 1997. Sci. Total Environ. 232:123-60.
Li, Y.F. and Macdonald, R.W. 2005. Sources and pathways of selected organochlorine pesticides to the
Arctic and the effect of pathway divergence on HCH trends in biota: a review. Sci. Total Environ.
342:87-106.
O’Shea, T.J. and Brounell Jr, R.L. 1994. Organochlorine and metal contaminants in baleen whales: areview and evaluation of conservation implications. Sci. Total Environ. 14:179-200.
Pastene, L.A., Fujise, Y. and Hatanaka. 2014. The Japanese Whale Research Program under Special
Permit in the Antarctic-Phase II (JARPAII): origin, objectives, research progress made in the period
2005/06-2010/2011 and relevance for management and conservation of whales and the ecosystem.
Paper SC/F14/J1 presented to the IWC Sponsored Meeting to Review Data and Results from theJapanese Whale Research Program under Special Permit in the Antarctic-Phase II (JARPAII) (JARPAII
Review Meeting), February 2014.
Tanabe, S., Miura, S. and Tatsukawa, R. 1986. Variations of organochlorine residues with age and sex in
Antarctic minke whale. Mem. Natl. Inst. Polar Res., Spec. Issue, 44: 174-181.
Tanabe, S., Aono, S., Fujita, K., Nakata, H., Fujise, Y., Kato, H. and Tatsukawa, R. 1999. Temporal trendof persistent organochlorine residues in minke whale (Balaenoptera acutorostrata) collected from theAntarctic during 1984-1995. Paper SC/51/E4 presented to the Scientific Committee of International
Whaling Commission, May, Grenada. 8pp.
Tanabe, S., Niimi S., Minh, T.B., Miyazaki, N. and Petrov, E.A. 2003. Temporal trends of persistentorganochlorine contamination in Russia: a case study of Baikal and Caspian Seal. Arch. Environ.
Contam. Toxicol. 44:533-45.
Weber, K. and Goerke, H. 2003. Persistent organic pollutants (POPs) in antarctic fish: levels, patterns,changes. Chemosphere 53:667-78.
Yasunaga, G., Fujise, Y., Zenitani, R., Tanabe, S. and Kato, H. 2006. Spatial and temporal variations inorganochlorine contaminants in the Antarctic minke whale, Balaenoptera bonaerensis. Paper
SC/D06/J29 presented to the IWC Sponsored Meeting to Review Data and Results form the Japanese
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4

Table 1. Organochlorine concentrations (ng/g fat wt.) in the blubber of mature male (21-25 years) of
Antarctic minke whales in Area V in JARPA during a period from 1988/89 to 2004/05 and JARPAII in
2010/2011
Area

Year
1988/89n5(

1990/915

1992/935

1994/955

1996/97

5

(
(
JARPA

(
(
1998/99

5

2000/015

2002/035(((
2004/05

5

Total

40

JARPA II 2010/11

5

(
(
(

Fat (%)
82.0
77.7 - 87.9
70.5
61.7 - 80.3
62.4
44.8 - 78.2
69.7
55.4 - 77.2
69.4
45.2 - 83.1
72.0
62.6 - 86.2
73.3
54.6 - 83.8
75.9
63.4 - 84.3
67.9
61.9 - 75.0
71.5
44.8 - 87.9
67.9
61.9 - 75.0

) (
) (
) (
) (
) (
) (
) (
) (
) (
) (
) (

PCBs
30
23 - 4033
20 - 7050
22 - 7838
26 - 4931
18 - 6027
18 - 35
17
10 - 27
24
21 - 26
28
21 - 4331
10 - 7828
21 - 43

) (
) (
) (
) (
) (
) (
) (
) (
) (
) (
) (

DDTs
110
71 - 150
120
57 - 260180
74 - 300
140
80 - 180130
44 - 300
110
50 - 150
69
30 - 13066
51 - 74100
81 - 160
110
30 - 300
100
81 - 160

) (
) (
) (
) (
) (
) (
) (
) (
) (
) (
) (

HCHs
1.8
0.6 - 3.2
1.8
0.6 - 4.1
1.6
0.4 - 3.8
1.4
0.4 - 3.0
0.5
<0.2 - 1.0
0.4
0.2 - 0.6
0.4
<0.1 - 0.4
0.8
0.7 - 0.9
0.8
<0.2 - 0.8
1.2<0.2 - 4.1
0.8<0.2 - 0.8

) (
) (
) (
) (
) (
) (
) (
) (
) (
) (
) (

HCB
230
130 - 340220
160 - 380260
130 - 400
280
180 - 380210
120 - 370
160
140 - 190
110
75 - 210150
110 - 190
140
110 - 190
200
75 - 400
140
110 - 190

) (
) (
) (
) (
) (
) (
) (
) (
) (
) (
) (

CHLs
37
27 - 5139
19 - 8456
25 - 9158
34 - 7345
17 - 8944
27 - 57
28
10 - 6028
23 - 3225
19 - 40
40
10 - 9125
19 - 40

)
)
)
)
)
)
)
)
)
)
)

Table 2. Simple linear correlation coefficients and probability between research years (1988/19892010/2011) and organochlorine contaminant concentrations (ng/g fat wt.) in the blubber of Antarctic
minke whales
LN (PCBs conc.) LN (DDTs conc.) LN (HCHs conc.) LN (HCB conc.) LN (CHLs conc.)
Constant

B±SE

70.4±21.9

165±4174.4±16.7

53.2±21.4

Reserch year

B±SE

-0.033±0.011-0.083±0.021-0.035±0.008-0.025±0.011

p value

0.004**<0.001***<0.001***0.025**: p <0.05, **: p <0.01, ***: p <0.001

5Sampling area

PCBs
0.08
0.06
0.04
0.02
0.00

0.25

DDTs
0.20
0.15
0.10
0.05
0.00

0'88/89
1 2'92/93
3 4'96/97
5 6'00/01
7 8 '04/05
9 10 11'10/11
12 13'90/91 '94/95 '98/99 '02/03

0.30
0.20
0.10

0'88/89
1 2'92/93
3 4'96/97
5 6'00/01
7 8'04/05
9 10 11'10/11
12 13'90/91 '94/95 '98/99 '02/03

Year

Concentrations (μg/g)

Concentrations (μg/g)

HCB
0.40

0.00

0'88/89
1 2'92/93
3 4'96/97
5 6'00/01
7 8'04/05
9 10 11'10/11
12 13

HCHs

0.004
0.003
0.002

0.000

0'88/89
1 2'92/93
3 4'96/97
5 6'00/01
7 8 '04/05
9 10 11'10/11
12 13'90/91 '94/95 '98/99 '02/03

Year

0.50

0.005

0.001

'90/91 '94/95 '98/99 '02/03

Year

Concentrations (μg/g)

0.10Concentrations (μg/g)

Concentrations (μg/g)

Figure 1. Sampling area of Antarctic minke whales in Area V

Year

0.10

CHLs
0.08
0.06
0.04
0.02
0.00

0'88/89
1 2'92/93
3 4'96/97
5 6'00/01
7 8'04/05
9 10 11'10/11
12 13'90/91 '94/95 '98/99 '02/03

Year

Figure 2. Temporal trend of organochlorine concentrations (ng/g fat wt.) in the blubber of Antarctic minke
whales from Area V during a period from 1988/89 to 2010/11

6

10Area-V

Ratio (Pesticides/PCBs)

1
DDT/PCB
HCH/PCB
HCB/PCB

0.1
CHL/PCB

0.01

0.001

'88/89 '92/93 '96/97 '00/01 '04/05'90/91 '94/95 '98/99 '02/03
Year'10/11Figure 3. Ratios of organochlorine pesticides and PCBs in the blubber of Antarctic minke whales from
Area V during 1988/89 and 2010/11 seasons7