radioactive cesium accumulation in seaweeds by the fukushima 1 nuclear power plant accident—two...
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JPR SYMPOSIUM Current status and future control of cesium contaminationin plants and algae in Fukushima
Radioactive cesium accumulation in seaweeds by the Fukushima 1Nuclear Power Plant accident—two years’ monitoring at Iwakiand its vicinity
Hiroshi Kawai • Akira Kitamura • Mari Mimura •
Tetsuro Mimura • Tomoya Tahara •
Daiki Aida • Kenji Sato • Hideaki Sasaki
Received: 31 July 2013 / Accepted: 25 September 2013 / Published online: 6 December 2013
� The Botanical Society of Japan and Springer Japan 2013
Abstract Accumulations of radionuclides in marine
macroalgae (seaweeds) resulting from the Fukushima 1
Nuclear Power Plant (F1NPP) accident in March 2011 have
been monitored for two years using high-purity germanium
detectors. Algal specimens were collected seasonally by
snorkeling at Nagasaki, Iwaki, Fukushima Prefecture
(Pref.), Japan, ca. 50 km perimeter from the F1NPP.
Additional collections were done at Soma, Hironocho,
Hisanohama and Shioyazaki in Fukushima Pref. as well as
at Chiba Pref. and Hyogo Pref. as controls. In May 2011,
specimens of most macroalgal species showed 137Cs levels
greater than 3,000 Bq kg-1 at Shioyazaki and Nagasaki.
The highest 137Cs level recorded 7371.20 ± 173.95
Bq kg-1 in Undaria pinnatifida (Harvey) Suringar on 2
May 2011, whereas seawater collected at the same time at
Shioyazaki and Nagasaki measured 8.41 ± 3.21 and
9.74 ± 3.43 Bq L-1, respectively. The concentration fac-
tor of marine macroalgae was estimated to be ca. 8–50,
depending on taxa and considering a weight ratio of wet/
dry samples of ca. 10. 137Cs level declined remarkably
during the following 5–6 months. In contrast, the 137Cs
level remained rather stable during the following 12–16
months, and maintained the range of 10–110 Bq kg-1.
Contamination was still detectable in many samples
in March 2013, 24 months after the most significant
pollution.
Keywords 134Cs � 137Cs � F1NPP � 40K �Radionuclide accumulation � Seaweeds
Introduction
Radioactive contamination of the coastal seawater fol-
lowing the Fukushima 1 Nuclear Power Plant (F1NPP)
accident was the most significant artificial radioactive
liquid release into the sea ever known, on a short time and
space scale basis (Buesseler et al. 2011; Linsley et al.
2005). The amount of radionuclides discharged from the
F1NPP immediate after the accident was estimated to be
5–10 PBq to the atmosphere and 3–6 PBq to the sea, the
latter being caused by direct leakages of the contaminated
cooling water (Estournel et al. 2012; Kawamura et al.
2011; Miyazawa et al. 2012; Tsumune et al. 2012).
The seawater contamination has become severe by (1) a
deposition from an atmospheric contamination plume, (2)
direct, artificial releases of highly contaminated waters into
the sea, and (3) the transport of radiopollutants into the sea
by surface water leaching through contaminated soil or by
Fukushima Daiichi Nuclear Power Station is cited as Fukushima 1
Nuclear Power Plant in the present manuscript.
H. Kawai (&)
Kobe University Research Center for Inland Seas, Rokkodai,
Nadaku, Kobe 657-8501, Japan
e-mail: [email protected]
A. Kitamura
Graduate School of Maritime Science, Fukae, Higashinada,
Kobe 658-0022, Japan
M. Mimura � T. Mimura
Graduate School of Science, Kobe University Rokkodai,
Rokkodai, Nadaku, Kobe 657-8501, Japan
T. Tahara
Iwaki Community Reconstruction Center, Iwaki Meisei
University, Iwaki, Fukushima 970-8551, Japan
D. Aida � K. Sato � H. Sasaki
Faculty of Science and Technology, Iwaki Meisei University,
Iwaki, Fukushima 970-8551, Japan
123
J Plant Res (2014) 127:23–42
DOI 10.1007/s10265-013-0603-1
river systems. The first case was most serious during mid-
March 2011, and the second from late March to early April
2011. The contaminated seawater may be diluted or has
been transported offshore by currents. Along the coast,
however, a significant portion of the radioactive Cs and
other radioactive substances are believed to have been
absorbed by coastal organisms or bound to suspended
particles, causing a deposition of radiopolluted sediments
on the sea bottom. The concentration of radionuclides
reached the maximum in mid-April 2011, but it thereafter
declined exponentially. However, in addition to the inflow
through the river systems, artificial release of radionuclides
from F1NPP is reported to have continued at least until
2012 (Kanda 2013).
Among the radionuclides discharged by the accident, the
effects of 134Cs and 137Cs are most serious because of their
high levels and long decay periods. These radionuclides are
considered to most substantially contribute to the contam-
ination of marine organisms due to the contaminated sea-
water. Marine macroalgae (so-called seaweeds) grow by
absorbing nutrient salts and other minerals directly from
seawater at the surface of their thalli. Cs? is soluble in
seawater, and algal cells are thought to absorb Cs? through
certain K? transporters (Kanter et al. 2010; Zhu and
Smolders 2000), resulting in Cs? accumulation within the
cells.
The concentration factors (CFs) of marine macroalgae
for 137Cs were reported to vary considerably from species
to species (Coughtrey and Thorne 1983; Pentreath 1976;
Tateda and Koyanagi 1994), but IAEA (2004) recom-
mended the value of 50. Marine macroalgae may also
capture the ions in phycocolloids such as alginate, fucan,
agar, and carrageenan, although the affinity of Cs? for
these phycocolloids is not well-established (Morris et al.
1980). Marine macroalgae are primary producers in
coastal ecosystems, and diverse benthic animals as well as
fishes feed on them. Therefore, the radioactive contami-
nation of marine macroalgae will be transferred to con-
sumer animals through the food chain, and may become
concentrated by biological accumulation.
Prior to the accident, the concentrations of 137Cs in the
surface water of the Pacific Ocean were in the range of
1–4 Bq m-3 (Ikeuchi 2003; Nakanishi et al. 2010; Povinec
et al. 2004), which mainly resulted from global fallout due
to atmospheric nuclear weapon tests. Tateda and Koyanagi
(1994) have reported the background concentrations of137Cs in representative green, red and brown marine mac-
roalgae, e.g. Ulva pertusa Kjellman, Neodilsea yendoana
Tokida, Saccharina religiosa (Miyabe) C.E. Lane, C.
Mayes, Druehl & G.W. Saunders (=Laminaria religiosa
Miyabe), Sargassum horneri (Turner) C. Agardh, S. thun-
bergii (Mertens ex Roth) Kuntze, in the range of ca.
0.03–037 Bq kg wet weight-1. Later, Morita et al. (2010)
have compared the level of 90Sr and 137Cs in Undaria
pinnatifida collected from three representative areas
(Nagasaki Pref., Kanagawa Pref. and Niigata Pref.) in
Japan and in Saccharina longissima (Miyabe) C.E. Lane,
C. Mayes, Druehl & G.W. Saunders (=Laminaria longiss-
ima Miyabe) from Hokkaido during a 1998–2008 period
and reported 137Cs levels of 0.03–0.08 and
0.05–0.09 Bq kg wet weight-1 for U. pinnatifida and
S. longissima, respectively. Morita et al. (2010) also
compared concentrations of 90Sr and 137Cs in some addi-
tional kelp and Sargassum species and reported 137Cs
concentrations of 0.02–0.34 kg wet weight-1.
Several agencies have conducted investigations to
measure the radioactive quantities of major fishery organ-
isms after the F1NPP accident. Some algal taxa have been
included in the target species, e.g., Pyropia (Porphyra),
Saccharina (Laminaria), Eisenia, Gloiopeltis, Monostro-
ma, but the number of species was rather limited, and
rather biased in respect to phylogenetic diversity, habitat,
and life history (e.g., intertidal vs. subtidal, annual vs.
perennial). In addition, measurement protocols were not
standardized among the investigations, and the detection
levels were sometimes rather high (e.g., [ 20 Bq kg-1 for
fresh specimens: http://www.jfa.maff.go.jp/e/inspection/
index.html) depending on the available facilities. There-
fore, it was difficult to compare the data to clarify the
general fate of radioactive contamination in marine mac-
roalgae, and to discuss the differences in the CFs for ra-
dionuclides among the taxa.
In the present study, we aimed to monitor the level of
radionuclides including 134Cs, 137Cs and 40K based on a
standardized protocol using high-purity germanium detec-
tors and to undertake multi-seasonal sampling as much as
possible.
Materials and methods
Specimens were seasonally collected by snorkeling at
Nagasaki, Fukushima Pref., ca. 50 km distant from the
F1NPP (Fig. 1). Additional specimens were collected at the
following localities: Hironocho, Hisanohama, Shioyazaki
and Soma (Fukushima Pref.); Iwanuma (Miyagi Pref.);
Kamogawa and Katsuura (Chiba Pref.); and Iwaya (Hyogo
Pref.) (Fig. 1). The list of the specimens is shown in Table 1
(measurements made at Kobe University) and Table 2
(measurements made at Iwaki Meisei University).
For the measurements at Kobe University, sorted spec-
imens were identified based on their morphology, prelim-
inarily air-dried overnight using a fan at room temperature,
and then dried in an oven at 90–100 �C for 8 h. The weight
ratios of wet/dry samples were roughly 10, and this value
was used in the comparisons of literature data based on wet
24 J Plant Res (2014) 127:23–42
123
samples, and concentration factors. Dried specimens were
preliminarily broken into fragments manually, and powdered
using a blender (Waring J-SPEC 7011BUJ, Conair Corp.,
Stamford, CT, USA). Powdered specimens were packed in
U-8 sample cups (56 mm ø and 68 mm high) and used for
measurement. The protocol of radioactivity measurements is
described in Mimura et al. (2014). In Tables 1 and 2, ‘‘Error’’
is the overall error estimated by the analyzing software from
systematic errors in the system together with the standard
deviation of the counting. Seawaters collected at the coasts of
Nagasaki and Shioyazaki in May 2011 were filled in U-8
sample cups and used for measurements without evaporation.
For the measurements at Iwaki Meisei University, sorted
specimens were identified based on their morphology,
washed with fresh water and pre-dried at room tempera-
ture. Dried specimens were desiccated in an oven at 60 �C
for 48 h, powdered using a blender, and packed in U-8
sample cups. 134Cs and 137Cs were measured using a
GEM40P4-76 germanium detector (Seiko EG & G, Tokyo,
Japan) following the manufacturer’s instructions.
The first collections (May 2011) of the macroalgal
specimens were kept frozen at -20 �C until drying.
However, this protocol resulted in some loss of radioac-
tivity in meltwater (dripping). Accordingly, in order to
assess the loss of radioactivity during thawing, some
specimens (collected in July 2011) were either frozen
before drying or directly dried, and the radioactivity was
compared between these drying protocols. In addition, the
radioactivity of the meltwater obtained from the thawed
specimens was also measured.
Statistical problems
In some radioactivity measurements, such as for macroal-
gal samples, we could not obtain a sufficient amount of
samples that allow us to ensure statistical reliance of the
measurement. There was also a limitation in the total
running time on a germanium detector. In other cases, the
total volume of collected samples was not large enough to
fill the U-8 sample cup, resulting in rather low detection
signals. For all these experiments, only data are presented
with notification that the precision of data was not statis-
tically tested.
Results
The 134Cs:137Cs ratios of examined specimens were plotted
according to time series (Fig. 2). The ratio reduced to ca.
0.6 after two years, which agreed well with the expected
value by natural decay (0.79 after one year, and 0.64 after
two years).
Results of the measurements at Kobe University (134Cs,137Cs and 40K) and Iwaki Meisei University (134Cs and137Cs) are listed in Table 1 and Table 2, respectively. On 2
May and 6 May 2011 (Shioyazaki and Nagasaki, about
50 km from F1NPP), specimens of most macroalgal spe-
cies, i.e., Ulva pertusa, U. linza Linnaeus, Scytosiphon
lomentaria (Lyngbye) Link, Eisenia bicyclis (Kjellman)
Setchell, Undaria pinnatifida, Sargassum muticum (Yendo)
Fensholt, and S. thunbergii, showed 137Cs levels greater
than 3,000 Bq kg-1 (Figs. 3, 4). The highest 137Cs level
was 7,371.20 ± 173.95 Bq kg-1 in Undaria pinnatifida
(Fig. 3; sample code k010 in Table 1). The 134Cs:137Cs
ratio was ca. 0.97. Exceptionally, Gloiopeltis furcata
(Postels & Ruprecht) J. Agardh showed a relatively lower
value of 767.37 ± 32.90 Bq kg-1 (Fig. 4; sample code
k014 in Table 1). Seawater collected on May 2 at Shi-
oyazaki (Fig. 3) and Nagasaki (Fig. 4) measured
8.41 ± 3.21 and 9.74 ± 3.43 Bq L-1, respectively. In
control samples from Awaji Island in May 2011, 137Cs
levels were below the detectable level of 0.001–0.002 in
Undaria pinnatifida, Sargassum muticum, and Ulva pertusa
(Table 1).137Cs levels remarkably declined at Nagasaki within the
following 5–6 months. In July 2011, 137Cs ranged from ca.
300–600 Bq kg-1 (Fig. 5), declined to 40–200 Bq kg-1 in
October 2011 (Fig. 6) and became lower than 100 Bq kg-1
in most samples in July 2012 (Fig. 7) and December 2012
(Fig. 8). However, 137Cs was still detectable in the range of
10–100 Bq kg-1 in many samples in March 2013,
24 months after the date of highest records (Fig. 9).
The progression of 137Cs levels differed in different
taxa. In the green alga Ulva pertusa, which has very short
lifetime (ephemeral species), 137Cs levels clearly declined
during the summer of 2011, but remained in the range of
10–110 Bq kg-1 from winter 2011 to spring 2013
(Fig. 10). 40K was somewhat higher in May 2011 samples,
Fig. 1 Locations of the collection sites of the specimens investigated
in the present study
J Plant Res (2014) 127:23–42 25
123
Ta
ble
1L
ist
of
sam
ple
sex
amin
edat
Ko
be
Un
iver
sity
,an
dth
ere
sult
so
f134C
s,137C
san
d40K
mea
sure
men
tsfo
rd
ried
sam
ple
sw
hen
no
tsp
ecia
lly
no
ted
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
n
and
nat
ure
of
sam
ple
s)
134C
s137C
s40K
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
k001
9Ju
ly2011
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Fer
tile
thal
li,
dir
ectl
ydri
ed
320.5
716.0
70.0
12
346.1
422.7
00.0
09
1,1
32.7
0310.8
10.2
82
k002
2M
ay2011
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sS
hio
yaz
aki,
Iwak
i,
Fukush
ima
Fro
zen
5,4
06.7
068.2
20.0
29
5557.9
093.1
00.0
20
2,4
94.3
0375.9
50.3
09
k003
2M
ay2011
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Nag
asak
i,Iw
aki,
Fukush
ima
Fro
zen
3,0
09.5
097.1
00.0
54
2897.8
0122.5
60.0
42
2,7
80.8
01013.3
00.9
42
k004
9Ju
ly2011
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed487.5
458.3
10.0
51
567.8
374.2
00.0
46
n.d
.n.d
.1.3
81
k005
2M
ay2011
Phae
ophyce
aeF
uca
les
Sarg
ass
um
thunber
gii
Shio
yaz
aki,
Iwak
i,
Fukush
ima
Fro
zen
4,1
51.9
060.1
10.0
26
4239.9
081.1
90.0
20
2,5
07.5
0384.8
00.3
15
k006
2M
ay2011
Phae
ophyce
aeE
ctoca
rpal
ess.
l.Scy
tosi
phon
lom
enta
ria
Shio
yaz
aki,
Iwak
i,
Fukush
ima
Fro
zen
5,4
17.1
0131.0
10.0
73
5672.5
0172.2
70.0
41
n.d
.n.d
.1.0
13
k007
6M
ay2011
Phae
ophyce
aeE
ctoca
rpal
ess.
l.Scy
tosi
phon
lom
enta
ria
Nag
asak
i,Iw
aki,
Fukush
ima
Fro
zen
4,5
44.9
069.5
40.0
31
4616.0
093.9
50.0
21
n.d
.n.d
.0.3
76
k008
2M
ay2011
Phae
ophyce
aeF
uca
les
Sarg
ass
um
muti
cum
Shio
yaz
aki,
Iwak
i,
Fukush
ima
Fro
zen
3,9
91.3
098.2
60.0
49
4282.4
0132.0
40.0
38
1,9
81.8
0808.5
70.7
60
k009
2M
ay2011
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Shio
yaz
aki,
Iwak
i,
Fukush
ima
Fro
zen
4,2
31.9
0138.5
20.0
70
4340.2
0182.5
50.0
62
n.d
.n.d
.1.4
09
k010
2M
ay2011
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Shio
yaz
aki,
Iwak
i,
Fukush
ima
Fro
zen
7,4
33.5
0133.3
30.0
60
7371.2
0173.9
50.0
47
1,1
52.2
0799.5
20.8
00
k011
9Ju
ly2011
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Juven
ile
thal
li,
dir
ectl
ydri
ed
529.9
248.5
60.1
60
569.0
860.4
30.1
42
n.d
.n.d
.3.3
96
k012
9Ju
ly2011
Phae
ophyce
aeF
uca
les
Sarg
ass
um
horn
eri
Nag
asak
i,Iw
aki,
Fukush
ima
Bas
alport
ion,
dir
ectl
ydri
ed
457.6
522.2
40.0
53
501.0
629.9
00.0
44
2,8
67.3
0411.9
91.0
61
k013
2M
ay2011
Ulv
ophyce
aeU
lval
esU
lva
linza
Shio
yaz
aki,
Iwak
i,
Fukush
ima
Fro
zen
5,5
16.5
0128.9
90.0
73
5433.8
0165.3
10.0
38
n.d
.n.d
.0.9
44
k014
6M
ay2011
Rhodophyce
aeG
igar
tinal
esG
loio
pel
tis
furc
ata
Nag
asak
i,Iw
aki,
Fukush
ima
Fro
zen
691.8
623.5
00.0
15
767.3
732.9
00.0
12
371.8
5260.9
50.2
57
k015
6M
ay2011
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Fro
zen
4,6
90.0
071.8
90.0
31
4810.3
096.6
50.0
23
2,9
57.8
0462.1
10.3
83
k016
9Ju
ly2011
Rhodophyce
aeG
igar
tinal
esG
rate
loupia
lance
ola
ta
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed318.4
828.8
30.1
06
352.4
036.1
70.0
90
n.d
.n.d
.2.0
73
k017
9Ju
ly2011
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Nag
asak
i,Iw
aki,
Fukush
ima
Fro
zen
606.5
066.7
30.2
00
576.9
385.9
60.1
99
n.d
.n.d
.5.1
82
k018
9Ju
ly2011
Phae
ophyce
aeF
uca
les
Sarg
ass
um
horn
eri
Nag
asak
i,Iw
aki,
Fukush
ima
Tip
port
ion,
dir
ectl
ydri
ed
340.7
721.6
50.0
18
321.1
526.7
10.0
16
4,7
83.7
0525.7
91.2
80
k019
9Ju
ly2011
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
japonic
a
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed426.8
737.5
20.1
36
425.3
245.3
40.0
97
n.d
.n.d
.2.6
38
k020
9Ju
ly2011
Phae
ophyce
aeF
uca
les
Sarg
ass
um
yam
adae
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed499.6
225.7
10.0
64
498.7
433.7
10.0
61
1,8
71.4
0446.7
51.2
95
k023
9Ju
ly2011
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Fer
tile
thal
li,
froze
n
278.3
816.8
90.0
45
292.4
021.8
80.0
38
1,9
87.9
0355.5
20.9
76
26 J Plant Res (2014) 127:23–42
123
Ta
ble
1co
nti
nu
ed
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
n
and
nat
ure
of
sam
ple
s)
134C
s137C
s40K
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
k024
17
May
2011
Phae
ophyce
aeF
uca
les
Sarg
ass
um
muti
cum
Iway
a,A
waj
iIs
l.,
Hyogo
Dir
ectl
ydri
edn.d
.0.0
00.0
02
n.d
.0.0
00.0
03
2,7
68.8
025.0
4–
k025
17
May
2011
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Iway
a,A
waj
iIs
l.,
Hyogo
Dir
ectl
ydri
edn.d
.0.0
00.0
01
n.d
.0.0
00.0
01
1,8
41.8
034.1
50.0
29
k026
31
May
2011
Phae
ophyce
aeE
ctoca
rpal
ess.
l.C
olp
om
enia
sinuosa
Iway
a,A
waj
iIs
l.,
Hyogo
Dir
ectl
ydri
edn.d
.0.0
00.0
01
n.d
.0.0
00.0
01
496.5
045.3
00.0
42
k027
31
May
2011
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Iway
a,A
waj
iIs
l.,
Hyogo
Dir
ectl
ydri
edn.d
.0.0
00.0
01
n.d
.0.0
00.0
01
1,1
47.6
042.5
30.0
37
k028
30
May
2011
Phae
ophyce
aeE
ctoca
rpal
ess.
l.Scy
tosi
phon
lom
enta
ria
Iway
a,A
waj
iIs
l.,
Hyogo
Dir
ectl
ydri
edn.d
.0.0
00.0
07
n.d
.0.0
00.0
05
1,9
55.9
0188.0
90.1
76
k029
6S
epte
mber
2011
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed681.8
620.6
80.0
43
773.2
230.8
30.0
34
2,1
15.4
0278.5
80.7
03
k030
6S
epte
mber
2011
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.2
20
202.8
543.4
80.1
58
n.d
.n.d
.4.5
19
k031
6S
epte
mber
2011
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
japonic
a
Nag
asak
i,Iw
aki,
Fukush
ima
Juven
ile
thal
lus,
dir
ectl
ydri
ed
193.7
025.0
70.0
97
230.3
136.7
10.0
86
4,2
14.1
0860.9
82.3
89
k032
6S
epte
mber
2011
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Old
sporo
phyll
,
dir
ectl
ydri
ed
255.0
231.3
80.1
21
224.3
436.2
60.1
08
n.d
.n.d
.2.7
16
k035
14
Oct
ober
2011
Rhodophyce
aeG
igar
tinal
esH
ypnea
asi
ati
caN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed114.0
428.8
80.0
45
161.9
628.9
10.0
39
2,4
23.0
01144.6
01.1
08
k036
14
Oct
ober
2011
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed36.5
64.7
50.0
06
43.0
56.6
70.0
07
1,0
13.1
0194.7
90.1
77
k037
14
Oct
ober
2011
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
japonic
a
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed57.6
44.2
00.0
05
67.4
16.0
90.0
05
1,1
20.3
0158.4
40.1
37
k038
14
Oct
ober
2011
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed51.4
29.6
70.0
14
64.2
910.7
40.0
13
1,3
80.3
0372.9
80.3
48
k039
14
Oct
ober
2011
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Mat
ure
thal
li,
dir
ectl
ydri
ed
105.9
94.7
80.0
04
114.0
06.6
60.0
04
995.0
4126.9
00.1
09
k040
14
Oct
ober
2011
Rhodophyce
aeG
igar
tinal
esN
eodil
sea
yendoana
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed53.9
26.2
10.0
09
68.4
68.4
30.0
07
1,5
50.9
0264.1
90.2
33
k041
14
Oct
ober
2011
Phae
ophyce
aeF
uca
les
Sarg
ass
um
yam
adae
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed200.1
714.0
10.0
13
229.2
017.5
40.0
12
1,5
22.6
0401.8
20.3
80
k042
14
Oct
ober
2011
Rhodophyce
aeG
igar
tinal
esA
hnfe
ltio
psi
s
para
doxa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed59.9
15.3
30.0
07
86.6
57.6
80.0
06
761.0
2184.2
20.1
70
k043
14
Oct
ober
2011
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Juven
ile
thal
li,
dir
ectl
ydri
ed
59.5
76.3
30.0
08
69.1
58.2
50.0
08
1,7
42.1
0259.7
90.2
26
k045
14
Oct
ober
2011
Rhodophyce
aeC
eram
iale
sC
hondri
a
crass
icauli
s
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed121.4
07.2
30.0
06
111.8
19.1
80.0
08
2,7
72.7
0244.7
40.1
92
k046
2M
ay2011
Sea
wat
erS
hio
yaz
aki,
Iwak
i,
Fukush
ima
Sea
wat
er9.5
42.2
50.0
04
8.4
13.2
10.0
03
n.d
.n.d
.0.0
96
k047
2M
ay2011
Sea
wat
erN
agas
aki,
Iwak
i,
Fukush
ima
Sea
wat
er11.2
72.1
50.0
03
9.7
43.4
30.0
03
n.d
.n.d
.0.0
94
J Plant Res (2014) 127:23–42 27
123
Ta
ble
1co
nti
nu
ed
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
n
and
nat
ure
of
sam
ple
s)
134C
s137C
s40K
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
k048
9Ju
ly2011
Mel
twat
er(d
rippin
g)
Nag
asak
i,Iw
aki,
Fukush
ima
Fro
mU
ndari
a
pin
nati
fida
39.4
83.1
00.0
03
42.2
14.0
50.0
03
340.4
597.7
80.0
91
k049
9Ju
ly2011
Mel
twat
er(d
rippin
g)
Nag
asak
i,Iw
aki,
Fukush
ima
Fro
m
Scy
tosi
phon
lom
enta
ria
344.7
18.6
30.0
05
383.0
912.0
10.0
05
n.d
.n.d
.0.1
20
k050
9Ju
ly2011
Mel
twat
er(d
rippin
g)
Shio
yaz
aki,
Iwak
i,
Fukush
ima
Fro
m
Sarg
ass
um
thunber
gii
402.9
78.8
60.0
05
436.7
212.1
40.0
04
502.6
5116.1
40.1
08
k051
9Ju
ly2011
Mel
twat
er(d
rippin
g)
Shio
yaz
aki,
Iwak
i,
Fukush
ima
Fro
mE
isen
ia
bic
ycli
s
697.8
711.1
90.0
06
809.5
016.2
00.0
05
440.8
3113.3
20.1
06
k052
5D
ecem
ber
2011
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Juven
ile
thal
li,
dir
ectl
ydri
ed
54.3
87.1
30.0
09
69.8
412.2
70.0
09
2,5
12.0
0310.2
00.2
32
k053
5D
ecem
ber
2011
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Mat
ure
thal
li,
dir
ectl
ydri
ed
96.8
48.5
20.0
07
106.1
112.0
00.0
10
2,2
58.5
0275.4
00.2
10
k054
5D
ecem
ber
2011
Rhodophyce
aeG
igar
tinal
esN
eodil
sea
yendoana
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed45.3
07.3
00.0
10
40.5
813.3
20.0
12
1,0
82.4
0281.8
00.2
49
k056
5D
ecem
ber
2011
Rhodophyce
aeC
ora
llin
ales
Call
iart
hro
nsp
.N
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed25.5
65.1
70.0
07
34.1
08.9
50.0
07
n.d
.n.d
.0.1
97
k057
5D
ecem
ber
2011
Rhodophyce
aeC
eram
iale
sD
asy
ase
ssil
isN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed219.4
322.2
80.0
22
234.5
929.3
30.0
21
4,1
01.2
0705.2
10.5
92
k058
5D
ecem
ber
2011
Phae
ophyce
aeF
uca
les
Sarg
ass
um
yam
adae
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed70.4
97.9
30.0
07
82.2
211.7
40.0
10
2,0
37.5
0297.7
00.2
34
k059
5D
ecem
ber
2011
Rhodophyce
aeG
igar
tinal
esA
hnfe
ltio
psi
s
para
doxa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed100.8
59.7
20.0
10
92.0
711.7
50.0
09
468.7
1261.3
10.2
48
k060
5D
ecem
ber
2011
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
japonic
a
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed67.1
47.0
70.0
07
78.8
210.2
10.0
08
1,7
93.1
0259.9
50.2
09
k061
5D
ecem
ber
2011
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
japonic
a
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed57.1
28.5
10.0
11
59.3
413.5
30.0
11
2,2
79.1
0351.1
70.2
83
k062
5D
ecem
ber
2011
Phae
ophyce
aeR
alfs
iale
sA
nali
pus
japonic
us
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
48
197.2
041.7
00.0
42
n.d
.n.d
.1.2
85
k063
5D
ecem
ber
2011
Rhodophyce
aeG
igar
tinal
esG
loio
pel
tis
furc
ata
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed51.7
710.0
60.0
08
53.6
511.7
10.0
11
592.8
7309.5
70.2
96
k064
7M
arch
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
horn
eri
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed133.8
723.4
70.0
31
187.5
830.5
40.0
23
2,0
15.0
0856.6
00.8
31
k065
7M
arch
2012
Rhodophyce
aeB
angia
les
Bangia
fusc
opurp
ure
a
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed160.5
18.9
80.0
09
226.2
213.8
00.0
09
936.7
0256.6
00.2
40
k066
7M
arch
2012
Ulv
ophyce
aeU
lval
esU
lva
linza
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed66.2
510.3
00.0
16
85.1
614.6
00.0
15
1,8
65.0
0443.3
00.4
08
k067
7M
arch
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
thunber
gii
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed106.3
76.4
00.0
07
137.0
39.2
40.0
06
1,6
54.0
0208.1
00.1
78
k068
7M
arch
2012
Phae
ophyce
aeE
ctoca
rpal
ess.
l.Scy
tosi
phon
lom
enta
ria
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed82.4
87.8
60.0
08
115.5
910.5
50.0
09
2,4
42.0
0285.5
00.2
37
28 J Plant Res (2014) 127:23–42
123
Ta
ble
1co
nti
nu
ed
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
n
and
nat
ure
of
sam
ple
s)
134C
s137C
s40K
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
k069
7M
arch
2012
Rhodophyce
aeB
angia
les
Pyr
opia
yezo
ensi
s
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed24.4
74.7
80.0
08
51.0
69.6
10.0
08
1,1
95.0
0252.3
00.2
30
k070
7M
arch
2012
Phae
ophyce
aeE
ctoca
rpal
ess.
l.P
etalo
nia
fasc
iaN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed53.6
88.5
90.0
13
84.3
712.5
00.0
14
3,1
59.0
0446.9
00.3
81
k071
7M
arch
2012
Ulv
ophyce
aeU
lval
esM
onost
rom
a
nit
idum
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed46.9
99.5
80.0
17
69.7
110.9
90.0
13
1,6
14.0
0412.7
00.4
00
k072
7M
arch
2012
Phae
ophyce
aeR
alfs
iale
sA
nali
pus
japonic
us
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed76.4
85.7
10.0
06
105.7
78.0
00.0
05
1,0
64.0
0184.9
00.1
64
k073
7M
arch
2012
Phae
ophyce
aeR
alfs
iale
sA
nali
pus
japonic
us
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed93.2
76.4
70.0
08
101.1
88.3
20.0
08
1,5
12.0
0258.0
00.2
43
k074
7M
arch
2012
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed33.6
94.5
80.0
05
62.9
16.4
40.0
05
1,6
42.0
0178.6
00.1
48
k075
7M
arch
2012
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed26.9
63.9
50.0
05
37.9
25.4
30.0
05
2,9
99.0
0193.9
00.1
40
k076
9A
pri
l2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
horn
eri
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed17.4
32.0
90.0
03
21.7
52.4
00.0
03
1,9
96.7
0101.6
60.0
82
k077
9A
pri
l2012
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed42.6
34.3
50.0
06
60.7
15.6
50.0
06
862.8
7172.4
80.1
64
k078
9A
pri
l2012
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed21.7
11.8
30.0
02
28.4
52.4
80.0
02
1,5
88.5
089.1
30.0
73
k079
9A
pri
l2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
thunber
gii
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed67.5
72.9
70.0
03
90.2
24.1
90.0
03
1,2
93.0
01016.6
00.0
88
k080
9A
pri
l2012
Phae
ophyce
aeD
esm
ares
tial
esD
esm
are
stia
ligula
ta
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
07
n.d
.0.0
00.0
07
1,7
43.3
0203.4
90.1
86
k081
9A
pri
l2012
Phae
ophyce
aeE
ctoca
rpal
ess.
l.Scy
tosi
phon
lom
enta
ria
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed48.6
62.9
90.0
03
71.7
64.1
70.0
03
1,6
03.2
0115.5
10.0
99
k082
9A
pri
l2012
Rhodophyce
aeR
hodym
enia
les
Lom
enta
ria
hako
date
nsi
s
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed157.8
23.9
60.0
03
221.7
16.0
00.0
03
897.3
395.5
90.0
86
k083
9A
pri
l2012
Rhodophyce
aeB
angia
les
Pyr
opia
yezo
ensi
s
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed38.6
43.2
60.0
04
49.6
53.9
20.0
04
967.2
3130.0
20.1
20
k084
9A
pri
l2012
Rhodophyce
aeC
eram
iale
sP
tero
siphonia
pin
nula
ta
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed253.7
67.2
20.0
07
360.9
510.6
10.0
06
2,1
49.9
0190.2
00.1
69
k085
9A
pri
l2012
Rhodophyce
aeG
igar
tinal
esA
hnfe
ltio
psi
s
para
doxa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed29.8
02.2
40.0
03
44.0
42.9
10.0
02
982.3
087.2
70.0
77
k086
9A
pri
l2012
Phae
ophyce
aeE
ctoca
rpal
ess.
l.C
olp
om
enia
sinuosa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed29.8
62.6
00.0
04
41.4
63.6
40.0
04
649.3
3113.4
40.1
07
k087
9A
pri
l2012
Phae
ophyce
aeE
ctoca
rpal
ess.
l.C
olp
om
enia
sinuosa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed222.6
39.1
20.0
10
302.9
912.3
90.0
09
3,8
65.9
0282.4
80.2
43
k088
9A
pri
l2012
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
japonic
a
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed10.0
51.8
90.0
03
15.2
82.5
90.0
03
1,9
88.0
0103.7
10.0
84
k089
9A
pri
l2012
Phae
ophyce
aeR
alfs
iale
sA
nali
pus
japonic
us
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed53.8
92.7
50.0
03
77.9
13.9
00.0
03
983.2
995.0
30.0
85
J Plant Res (2014) 127:23–42 29
123
Ta
ble
1co
nti
nu
ed
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
n
and
nat
ure
of
sam
ple
s)
134C
s137C
s40K
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
k090
9A
pri
l2012
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed7.8
41.1
70.0
02
8.5
81.5
30.0
02
1,0
51.4
076.6
10.0
07
k091
9A
pri
l2012
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Juven
ile
thal
li,
dir
ectl
ydri
ed
8.3
02.8
90.0
05
18.2
12.9
60.0
04
1,9
05.0
0142.1
20.1
23
k092
9A
pri
l2012
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Sporo
phyll
,
dir
ectl
ydri
ed
16.7
31.9
80.0
03
22.4
92.5
40.0
03
2,7
67.4
0104.0
90.0
77
k093
10
Apri
l
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
yam
adae
Yosh
io,
Kat
suura
,
Chib
a
Dir
ectl
ydri
edn.d
.0.0
00.0
03
n.d
.0.0
00.0
03
1,1
84.0
0102.9
80.0
91
k094
10
Apri
l
2012
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sY
osh
io,
Kat
suura
,
Chib
a
Dir
ectl
ydri
edn.d
.0.0
00.0
02
n.d
.0.0
00.0
02
1,7
45.1
093.1
40.0
76
k095
10
Apri
l
2012
Phae
ophyce
aeD
icty
ota
les
Padin
a
arb
ore
scen
s
Yosh
io,
Kat
suura
,
Chib
a
Dir
ectl
ydri
edn.d
.0.0
00.0
06
n.d
.0.0
00.0
06
1,5
79.4
0183.4
20.1
66
k096
10
Apri
l
2012
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Yosh
io,
Kat
suura
,
Chib
a
Dir
ectl
ydri
edn.d
.0.0
00.0
03
n.d
.0.0
00.0
03
1,9
91.1
094.5
90.0
75
k097
10
Apri
l
2012
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sK
amogaw
a,C
hib
aD
irec
tly
dri
edn.d
.0.0
00.0
03
n.d
.0.0
00.0
03
1,6
52.3
095.3
90.0
79
k098
10
Apri
l
2012
Phae
ophyce
aeL
amin
aria
les
Eck
lonia
cava
Kam
ogaw
a,C
hib
aD
irec
tly
dri
edn.d
.0.0
00.0
03
n.d
.0.0
00.0
03
2,7
14.6
0119.1
20.0
92
k099
10
Apri
l
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
fusi
form
e
Kam
ogaw
a,C
hib
aD
irec
tly
dri
edn.d
.0.0
00.0
02
n.d
.0.0
00.0
02
3,2
36.6
091.8
20.0
61
k100
10
Apri
l
2012
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Kam
ogaw
a,C
hib
aD
irec
tly
dri
edn.d
.0.0
00.0
03
n.d
.0.0
00.0
03
1,9
22.9
0103.4
20.0
84
k101
23
May
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
horn
eri
Ter
ashim
a,Iw
anum
a,
Miy
agi
Dir
ectl
ydri
ed67.1
226.2
40.0
29
76.0
523.0
30.0
22
1,7
01.7
0723.2
20.7
11
k102
23
May
2012
Ulv
ophyce
aeU
lval
esU
lva
pro
life
raT
eras
him
a,Iw
anum
a,
Miy
agi
Dir
ectl
ydri
ed370.1
320.4
60.0
23
485.8
727.1
60.0
22
1,2
68.7
0663.9
50.6
55
k103
23
May
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
horn
eri
Mat
sukaw
aura
,S
om
a,
Fukush
ima
Dir
ectl
ydri
ed55.5
52.5
50.0
03
81.2
33.7
50.0
03
1,6
19.5
097.9
70.0
81
k104
23
May
2012
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Som
aP
ort
,S
om
a,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
12
n.d
.0.0
00.0
11
449.7
8329.1
70.3
29
k105
23
May
2012
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Mat
sukaw
aura
,S
om
a,
Fukush
ima
Dir
ectl
ydri
ed21.8
03.1
60.0
04
26.0
33.9
90.0
04
1,0
15.1
0157.7
00.1
48
k106
23
May
2012
Phae
ophyce
aeD
esm
ares
tial
esD
esm
are
stia
ligula
ta
Som
aP
ort
,S
om
a,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
05
6.2
55.0
10.0
05
1,2
61.7
0154.2
00.1
41
k107
23
May
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
muti
cum
Som
aP
ort
,S
om
a,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
09
13.2
98.6
00.0
08
2,1
81.5
1287.9
10.2
60
k108
23
May
2012
Rhodophyce
aeC
eram
iale
sD
eles
seri
a
serr
ula
ta
Som
aP
ort
,S
om
a,
Fukush
ima
Dir
ectl
ydri
ed14.2
64.0
30.0
05
25.1
74.3
40.0
04
1,7
23.8
0145.1
00.1
28
k109
9A
pri
l2012
Ulv
ophyce
aeU
lval
esM
onost
rom
a
nit
idum
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed25.7
33.5
10.0
07
27.3
25.0
20.0
06
703.1
1180.5
00.1
73
30 J Plant Res (2014) 127:23–42
123
Ta
ble
1co
nti
nu
ed
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
n
and
nat
ure
of
sam
ple
s)
134C
s137C
s40K
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
k110
23
May
2012
Rhodophyce
aeG
igar
tinal
esG
rate
loupia
lance
ola
ta
Mat
sukaw
aura
,
Som
a,
Fukush
ima
Dir
ectl
ydri
ed12.9
63.2
70.0
06
n.d
.0.0
00.0
05
825.7
4168.6
20.1
60
k111
23
May
2012
Rhodophyce
aeG
igar
tinal
esSch
izym
enia
dubyi
Mat
sukaw
aura
,
Som
a,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
04
n.d
.0.0
00.0
03
721.7
1108.0
10.1
01
k112
23
May
2012
Rhodophyce
aeG
igar
tinal
esSch
izym
enia
dubyi
Mat
sukaw
aura
,
Som
a,
Fukush
ima
Dir
ectl
ydri
ed19.6
86.7
30.0
07
17.9
77.1
40.0
07
882.6
4216.6
70.2
10
k113
23
May
2012
Rhodophyce
aeC
ora
llin
ales
Gel
idiu
mel
egans
Mat
sukaw
aura
,
Som
a,
Fukush
ima
Dir
ectl
ydri
ed60.9
14.6
60.0
06
90.9
26.2
30.0
06
1,1
65.7
0177.9
30.1
67
k115
23
May
2012
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Mat
sukaw
aura
,
Som
a,
Fukush
ima
Dir
ectl
ydri
ed49.3
52.5
00.0
03
54.7
03.3
10.0
03
1,4
28.5
099.2
70.0
08
k116
9D
ecem
ber
2012
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed36.7
33.0
30.0
04
54.4
64.9
80.0
04
0.0
00.0
00.2
09
k117
9D
ecem
ber
2012
Rhodophyce
aeG
igar
tinal
esC
hondru
s
gig
ante
us
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed13.6
11.8
40.0
02
22.8
92.2
20.0
02
0.0
00.0
00.1
32
k118
9D
ecem
ber
2012
Phae
ophyce
aeE
ctoca
rpal
ess.
l.P
etalo
nia
fasc
iaH
irono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed33.0
92.6
70.0
03
48.9
83.8
10.0
04
0.0
00.0
00.2
00
k119
9D
ecem
ber
2012
Rhodophyce
aeG
igar
tinal
esN
eodil
sea
longis
sim
a
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed13.6
62.1
50.0
02
n.d
.0.0
0–
0.0
00.0
00.1
39
k122
10
Dec
ember
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
yam
adae
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed17.0
51.7
90.0
02
22.0
22.6
30.0
03
1,2
99.0
088.1
30.0
75
k123
10
Dec
ember
2012
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
07
26.1
96.8
10.0
06
769.5
0208.6
00.2
02
k124
10
Dec
ember
2012
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
03
10.4
93.0
40.0
03
1,9
96.0
0106.0
00.0
86
k125
10
Dec
ember
2012
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed19.6
23.9
60.0
04
21.5
64.0
80.0
05
2,4
57.0
0160.1
00.1
35
k128
10
Dec
ember
2012
Phae
ophyce
aeD
icty
ota
les
Spato
glo
ssum
paci
ficu
m
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed41.5
32.9
20.0
04
68.9
15.6
20.0
04
2,4
84.0
0147.1
00.1
21
k130
10
Dec
ember
2012
Rhodophyce
aeB
angia
les
Pyr
opia
yezo
ensi
s
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed12.2
12.8
00.0
04
26.8
63.8
40.0
05
657.2
8148.7
00.1
43
k131
10
Dec
ember
2012
Ulv
ophyce
aeU
lval
esU
lva
pro
life
raN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
08
8.0
47.5
80.0
08
848.5
1236.5
60.2
29
k132
10
Dec
ember
2012
Ulv
ophyce
aeC
ladophora
les
Chaet
om
orp
ha
monil
iger
a
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
07
n.d
.0.0
0–
3,7
70.3
0247.2
00.2
14
k133
10
Dec
ember
2012
Rhodophyce
aeG
igar
tinal
esC
hondru
s
oce
llatu
s
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
03
6.6
83.5
80.0
04
677.0
3112.5
70.1
06
J Plant Res (2014) 127:23–42 31
123
Ta
ble
1co
nti
nu
ed
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
n
and
nat
ure
of
sam
ple
s)
134C
s137C
s40K
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
k134
10
Dec
ember
2012
Rhodophyce
aeG
igar
tinal
esG
rate
loupia
turu
turu
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed10.3
22.4
90.0
03
9.4
64.2
20.0
04
1,1
63.4
0128.0
20.1
16
k135
10
Dec
ember
2012
Rhodophyce
aeG
igar
tinal
esA
hnfe
ltio
psi
s
para
doxa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed10.6
42.1
40.0
02
9.8
41.8
70.0
03
604.9
481.6
60.0
76
k138
10
Dec
ember
2012
Rhodophyce
aeG
igar
tinal
esG
loio
pel
tis
furc
ata
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed64.9
58.0
00.0
14
92.3
312.2
50.0
13
5,1
90.1
0427.4
00.3
76
k139
10
Dec
ember
2012
Rhodophyce
aeG
igar
tinal
esG
rate
loupia
lance
ola
ta
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
07
8.5
16.2
70.0
06
688.5
8198.6
50.1
93
k140
10
Dec
ember
2012
Rhodophyce
aeG
igar
tinal
esP
loca
miu
m
cart
ilagin
eum
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed22.1
63.9
20.0
07
59.6
96.3
00.0
06
514.6
2206.4
70.2
04
k141
10
Dec
ember
2012
Rhodophyce
aeC
eram
iale
sC
hondri
a
crass
icauli
s
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed41.8
24.6
20.0
05
47.8
15.4
50.0
06
3,8
59.4
0213.1
10.1
74
k142
9D
ecem
ber
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
thunber
gii
His
anoham
a,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed345.9
65.9
50.0
04
592.6
798.3
20.0
04
1,4
01.5
0112.6
00.0
98
k143
9D
ecem
ber
2012
Rhodophyce
aeG
igar
tinal
esC
hondru
s
gig
ante
us
His
anoham
a,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed38.5
52.4
40.0
03
59.7
43.6
20.0
03
1,1
49.1
097.5
90.0
86
k144
9D
ecem
ber
2012
Rhodophyce
aeG
igar
tinal
esC
hondru
s
gig
ante
us
His
anoham
a,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed18.3
33.5
10.0
04
36.8
23.4
70.0
04
1,2
57.7
0122.8
10.1
10
k145
9D
ecem
ber
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
muti
cum
His
anoham
a,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed123.9
74.2
10.0
04
209.8
96.7
60.0
04
1,5
03.3
01290.7
00.1
13
k146
9D
ecem
ber
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
fusi
form
e
His
anoham
a,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed21.4
91.8
60.0
03
34.7
03.3
70.0
03
4,2
06.9
0116.5
20.0
78
k147
9D
ecem
ber
2012
Phae
ophyce
aeE
ctoca
rpal
ess.
l.C
olp
om
enia
sinuosa
His
anoham
a,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed219.9
74.8
80.0
04
363.6
57.7
00.0
03
3,0
25.4
0122.4
80.0
93
k148
9D
ecem
ber
2012
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
japonic
a
His
anoham
a,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed33.5
52.7
10.0
03
60.8
735.8
20.0
03
3,4
79.6
0118.9
00.0
86
k149
9D
ecem
ber
2012
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
japonic
a
His
anoham
a,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed34.0
32.8
20.0
03
54.7
43.6
10.0
03
3,2
18.6
0122.4
60.0
91
k150
9D
ecem
ber
2012
Rhodophyce
aeC
eram
iale
sC
hondri
a
crass
icauli
s
His
anoham
a,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed42.0
54.2
70.0
05
58.6
06.1
80.0
05
3,9
37.1
0186.6
40.1
47
k151
16
Mar
ch
2013
Phae
ophyce
aeF
uca
les
Sarg
ass
um
horn
eri
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
03
10.6
43.1
10.0
03
2,2
50.8
0108.2
80.0
85
k152
16
Mar
ch
2013
Phae
ophyce
aeF
uca
les
Sarg
ass
um
yam
adae
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed9.6
92.3
00.0
05
7.9
14.5
60.0
04
840.9
4140.7
40.1
32
32 J Plant Res (2014) 127:23–42
123
Ta
ble
1co
nti
nu
ed
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
n
and
nat
ure
of
sam
ple
s)
134C
s137C
s40K
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
k153
16
Mar
ch
2013
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed9.7
91.8
70.0
03
19.1
23.2
40.0
03
1,4
53.1
0117.8
20.1
03
k154
16
Mar
ch
2013
Phae
ophyce
aeL
amin
aria
les
Eis
enia
bic
ycli
sN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
07.1
81.8
40.0
03
1,2
74.5
091.3
20.0
79
k155
16
Mar
ch
2013
Phae
ophyce
aeF
uca
les
Sarg
ass
um
thunber
gii
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed13.9
22.3
50.0
03
20.9
02.8
80.0
03
1,7
38.2
0124.2
20.1
06
k156
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esA
hnfe
ltio
psi
s
flabel
lifo
rmis
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed16.7
13.7
70.0
08
22.8
07.5
30.0
07
1,3
49.4
0230.5
10.2
17
k158
16
Mar
ch
2013
Rhodophyce
aeR
hodym
enia
les
Lom
enta
ria
hako
date
nsi
s
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed34.7
73.0
80.0
04
60.4
74.4
30.0
04
993.4
2130.8
60.1
21
k159
16
Mar
ch
2013
Phae
ophyce
aeD
icty
ota
les
Pach
ydic
tyon
cori
ace
um
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed26.2
34.9
40.0
07
38.1
15.3
50.0
07
1,4
94.5
0229.9
10.2
16
k160
16
Mar
ch
2013
Ulv
ophyce
aeC
ladophora
les
Cla
dophora
sp.
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed50.8
85.2
30.0
06
75.1
16.1
00.0
06
1,0
29.2
0190.0
50.1
79
k161
16
Mar
ch
2013
Ulv
ophyce
aeU
lval
esU
lva
pro
life
raN
agas
aki,
Iwak
i,
Fukush
ima
Dir
ectl
ydri
ed44.6
64.5
80.0
06
67.0
55.6
60.0
06
1,2
18.0
0182.8
20.1
72
k162
16
Mar
ch
2013
Ulv
ophyce
aeC
ladophora
les
Chaet
om
orp
ha
monil
iger
a
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
04
10.2
33.0
70.0
04
3,3
97.3
0168.2
80.1
34
k164
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esA
hnfe
ltio
psi
s
para
doxa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed11.3
12.1
30.0
02
16.8
52.1
80.0
02
902.5
385.4
50.0
76
k165
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esG
loio
pel
tis
furc
ata
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
03
n.d
.0.0
00.0
03
534.6
6105.2
80.1
00
k166
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esG
rate
loupia
lance
ola
ta
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
04
n.d
.0.0
00.0
04
601.2
6125.9
20.1
20
k167
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esG
rate
loupia
lance
ola
ta
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
03
7.4
21.9
70.0
03
503.2
785.2
00.0
81
k169
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esP
oly
opes
affi
nis
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed27.5
34.4
10.0
04
48.0
14.0
60.0
04
533.0
0133.3
70.1
28
k170
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esP
oly
opes
affi
nis
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed12.2
02.4
20.0
04
13.5
13.6
00.0
03
377.6
5107.9
40.1
05
k171
16
Mar
ch
2013
Phae
ophyce
aeR
alfs
iale
sA
nali
pus
japonic
us
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed13.1
22.5
80.0
06
36.3
55.0
30.0
05
931.9
0180.1
70.1
72
k173
16
Mar
ch
2013
Rhodophyce
aeC
eram
iale
sC
hondri
a
crass
icauli
s
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed12.1
42.4
80.0
04
15.7
73.9
20.0
04
4,2
77.6
0152.0
70.1
10
k174
16
Mar
ch
2013
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed6.7
02.1
10.0
03
n.d
.0.0
00.0
29
1,3
52.8
0100.0
10.0
86
k175
16
Mar
ch
2013
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed5.2
92.1
00.0
03
11.2
72.9
60.0
03
1,8
08.8
0102.7
10.0
84
k176
16
Mar
ch
2013
Ulv
ophyce
aeC
ladophora
les
Cla
dophora
alb
ida
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed62.1
35.3
00.0
06
113.1
98.7
50.0
06
1,5
73.6
0205.1
20.1
90
k177
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esM
azz
ael
la
japonic
a
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
04
8.2
42.3
30.0
04
771.8
2109.9
90.1
03
J Plant Res (2014) 127:23–42 33
123
Ta
ble
1co
nti
nu
ed
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
n
and
nat
ure
of
sam
ple
s)
134C
s137C
s40K
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
k178
16
Mar
ch
2013
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed32.0
53.5
60.0
05
60.4
85.1
30.0
05
1,3
62.2
0161.8
70.1
48
k179
16
Mar
ch
2013
Ulv
ophyce
aeU
lval
esU
lva
per
tusa
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed26.0
64.6
00.0
07
58.1
75.7
40.0
06
1,0
16.7
0201.4
60.1
92
k180
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esC
hondru
s
gig
ante
us
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed8.0
32.0
00.0
03
13.8
13.0
90.0
03
537.8
890.5
30.0
86
k183
16
Mar
ch
2013
Rhodophyce
aeB
angia
les
Pyr
opia
yezo
ensi
s
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
05
11.2
62.8
80.0
04
759.9
0146.3
30.1
39
k184
16
Mar
ch
2013
Ulv
ophyce
aeU
lval
esU
lva
pro
life
raH
irono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed78.6
46.2
20.0
08
139.6
28.7
50.0
07
828.0
8230.7
20.2
24
k185
16
Mar
ch
2013
Phae
ophyce
aeE
ctoca
rpal
ess.
l.P
etalo
nia
fasc
iaH
irono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
05
21.6
93.2
60.0
04
1,3
94.7
0138.4
80.1
25
k186
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esN
eodil
sea
longis
sim
a
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed7.0
82.5
90.0
03
14.3
63.2
50.0
03
1,7
56.7
0113.0
20.0
96
k187
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esG
loio
pel
tis
furc
ata
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed14.6
32.8
90.0
05
18.1
73.3
60.0
05
437.2
7148.1
10.1
45
k188
16
Mar
ch
2013
Rhodophyce
aeG
igar
tinal
esG
loio
pel
tis
furc
ata
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed9.0
42.4
20.0
05
24.5
73.7
10.0
05
542.1
2143.0
30.1
38
k189
16
Mar
ch
2013
Phae
ophyce
aeR
alfs
iale
sA
nali
pus
japonic
us
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed22.1
02.3
00.0
03
36.3
63.0
20.0
03
1,1
13.9
01017.4
00.9
10
k190
16
Mar
ch
2013
Rhodophyce
aeC
eram
iale
sC
hondri
a
crass
icauli
s
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
ed29.8
22.8
40.0
03
49.9
54.2
50.0
03
3,0
51.8
0126.9
80.0
97
k191
16
Mar
ch
2013
Phae
ophyce
aeL
amin
aria
les
Undari
a
pin
nati
fida
Hir
ono,
Futa
ba,
Fukush
ima
Dir
ectl
ydri
edn.d
.0.0
00.0
03
11.9
32.6
70.0
02
1,3
13.6
089.8
20.0
77
Val
ues
of
det
ecti
on
lim
itin
Bq
kg
-1.
n.d
.m
eans
not
det
ecta
ble
(blo
wth
edet
ecti
on
lim
it).
Err
or
mea
ns
over
all
erro
res
tim
ated
by
the
anal
yzi
ng
soft
war
efr
om
syst
emat
icer
rors
inth
esy
stem
toget
her
wit
hth
est
andar
ddev
iati
on
of
the
counti
ng
34 J Plant Res (2014) 127:23–42
123
Ta
ble
2L
ist
of
sam
ple
sex
amin
edat
Iwak
iM
eise
iU
niv
ersi
ty,
and
the
resu
lts
of
134C
san
d137C
sm
easu
rem
ents
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
nan
d
nat
ure
of
sam
ple
s)
134C
s137C
s
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
IMU
001
2M
ay2011
Phae
ophyce
aeD
icty
ota
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Spato
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Fro
zen
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00
138
156
9,4
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179
133
IMU
002
2M
ay2011
Phae
ophyce
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uca
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Sarg
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zen
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003
6M
ay2011
Phae
ophyce
aeL
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aria
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hari
na
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aN
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zen
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116
144
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IMU
004
6M
ay2011
Phae
ophyce
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enia
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96.5
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IMU
005
6M
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Rhodophyce
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159
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146
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006
9Ju
ly2011
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ophyce
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ma
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zen
556
72.1
167
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88.2
148
IMU
007
9Ju
ly2011
Phae
ophyce
aeE
ctoca
rpal
ess.
l.C
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enia
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Nag
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i,Iw
aki,
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ima
Fro
zen
720
163
446
1,3
90
189
434
IMU
008
9Ju
ly2011
Phae
ophyce
aeE
ctoca
rpal
ess.
l.Scy
tosi
phon
lom
enta
ria
Nag
asak
i,Iw
aki,
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ima
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zen
590
53.4
98.5
1,0
80
68.3
101
IMU
009
9Ju
ly2011
Phae
ophyce
aeD
esm
ares
tial
esD
esm
are
stia
ligula
taN
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zen
154
7.7
011.3
255
9.9
811.5
IMU
010
9Ju
ly2011
Phae
ophyce
aeL
amin
aria
les
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enia
bic
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zen
676
16.0
21.0
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40
21.1
17.5
IMU
011
9Ju
ly2011
Rhodophyce
aeG
igar
tinal
esC
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soce
llatu
sN
agas
aki,
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ima
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zen
288
64.1
174
333
63.7
164
IMU
012
9Ju
ly2011
Rhodophyce
aeG
igar
tinal
esG
rate
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spars
aN
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aki,
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zen
569
50.0
102
1,0
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58.8
81.1
IMU
013
9Ju
ly2011
Rhodophyce
aeG
igar
tinal
esA
hnfe
ltio
psi
spara
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Nag
asak
i,Iw
aki,
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ima
Fro
zen
174
13.2
23.3
339
17.4
22.9
IMU
014
9Ju
ly2011
Rhodophyce
aeR
hodym
enia
les
Gast
rocl
oniu
mpaci
ficu
mN
agas
aki,
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i,F
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zen
733
43.8
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53.1
64.5
IMU
015
14
Oct
ober
2011
Phae
ophyce
aeF
uca
les
Sarg
ass
um
horn
eri
Nag
asak
i,Iw
aki,
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267
62.3
172
470
66.2
147
IMU
016
4Ju
ly2012
Phae
ophyce
aeR
alfs
iale
sA
nali
pus
japonic
us
Nag
asak
i,Iw
aki,
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ima
Dir
ectl
ydri
ed54.2
6.3
013.8
87.8
7.5
213.7
IMU
017
4Ju
ly2012
Phae
ophyce
aeD
icty
ota
les
Dic
tyota
dic
hoto
ma
Nag
asak
i,Iw
aki,
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ima
Dir
ectl
ydri
ed113
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150
9.3
114.7
IMU
018
4Ju
ly2012
Phae
ophyce
aeE
ctoca
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ess.
l.L
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esia
dif
form
isN
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ima
Dir
ectl
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213
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18.5
IMU
019
4Ju
ly2012
Phae
ophyce
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Dir
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IMU
020
4Ju
ly2012
Phae
ophyce
aeE
ctoca
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ess.
l.T
inocl
adia
crass
aN
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ima
Dir
ectl
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ed27.3
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9.6
227.0
IMU
021
4Ju
ly2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
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sum
Nag
asak
i,Iw
aki,
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ima
Dir
ectl
ydri
ed15.5
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4.2
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0
IMU
022
4Ju
ly2012
Phae
ophyce
aeF
uca
les
Sarg
ass
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eri
Nag
asak
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Dir
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ed17.7
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511.1
IMU
023
4Ju
ly2012
Phae
ophyce
aeF
uca
les
Sarg
ass
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thunber
gii
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asak
i,Iw
aki,
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ima
Dir
ectl
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ed14.3
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0
IMU
024
4Ju
ly2012
Phae
ophyce
aeL
amin
aria
les
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nati
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asak
i,Iw
aki,
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ima
Dir
ectl
ydri
edn.d
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IMU
025
4Ju
ly2012
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
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aN
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Dir
ectl
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9
IMU
026
4Ju
ly2012
Phae
ophyce
aeL
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les
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enia
bic
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agas
aki,
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i,F
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ima
Dir
ectl
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ed14.8
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919.0
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79.5
2
IMU
027
4Ju
ly2012
Ulv
ophyce
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lval
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lva
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asak
i,Iw
aki,
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ima
Dir
ectl
ydri
ed15.3
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610.5
23.7
4.3
211.0
IMU
028
4Ju
ly2012
Ulv
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ladophora
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om
orp
ha
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iger
aN
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aki,
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ectl
ydri
ed17.1
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911.0
26.5
4.9
312.7
IMU
029
4Ju
ly2012
Ulv
ophyce
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odia
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IMU
030
4Ju
ly2012
Ulv
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dal
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i,Iw
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ima
Dir
ectl
ydri
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8.9
619.5
IMU
031
4Ju
ly2012
Rhodophyce
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ora
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Cora
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apil
uli
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asak
i,Iw
aki,
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ima
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ed36.2
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7
IMU
032
4Ju
ly2012
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ora
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5
IMU
033
4Ju
ly2012
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ima
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IMU
034
4Ju
ly2012
Rhodophyce
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IMU
035
4Ju
ly2012
Rhodophyce
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igar
tinal
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5
IMU
036
4Ju
ly2012
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IMU
037
4Ju
ly2012
Rhodophyce
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eram
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aure
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agas
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ectl
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ed129
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911.3
239
9.5
99.8
4
J Plant Res (2014) 127:23–42 35
123
but was rather constant in the other samples (ca.
1,000–1,500 Bq kg-1). The annual brown algae Undaria
pinnatifida (Fig. 11) and Sargassum horneri (data not
shown) showed similar patterns of 137Cs progression: they
showed rapid decline in the first year, and continuously
declined until March 2013. The 40K level of Undaria
pinnatifida of the specimens from Chiba Pref. and Hyogo
Pref. were 1,840–1,990 Bq kg-1 (Fig. 11).Ta
ble
2co
nti
nu
ed
Sam
ple
code
Coll
ecti
on
dat
e
Tax
onom
yL
oca
lity
Note
(sam
ple
pre
par
atio
nan
d
nat
ure
of
sam
ple
s)
134C
s137C
s
Cla
ssO
rder
Spec
ies
Bq
kg
-1
Err
or
Det
ect.
lim
it
Bq
kg
-1
Err
or
Det
ect.
lim
it
IMU
038
10
Dec
ember
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
horn
eri
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed16.3
4.6
913.6
n.d
.0
16.0
IMU
039
10
Dec
ember
2012
Phae
ophyce
aeF
uca
les
Sarg
ass
um
sili
quast
rum
Nag
asak
i,Iw
aki,
Fukush
ima
Dir
ectl
ydri
ed60.5
7.0
416.2
118
8.3
713.1
IMU
040
10
Dec
ember
2012
Phae
ophyce
aeL
amin
aria
les
Sacc
hari
na
japonic
aN
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aki,
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ectl
ydri
ed26.2
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6.2
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Val
ues
of
det
ecti
on
lim
itin
Bq
kg
-1.
n.d
.m
eans
not
det
ecta
ble
(blo
wth
edet
ecti
on
lim
it).
Err
or
mea
ns
over
all
erro
res
tim
ated
by
the
anal
yzi
ng
soft
war
efr
om
syst
emat
icer
rors
inth
esy
stem
toget
her
wit
hth
est
andar
d
dev
iati
on
of
the
counti
ng
Fig. 2 Evolution of 134Cs/137Cs ratio of the specimens examined.
Dotted line indicates the theoretical expected value by the sponta-
neous decay of 134Cs and 137Cs
Fig. 3 Quantities of 134Cs and 137Cs of diverse marine macroalgae
and seawater collected in May 2011 at Shioyazaki, Iwaki, Fukushima
Pref., Japan. Measurement unit for seawater is Bq kg-1 (wet weight).
Asterisks show data by the measurement at Iwaki Meisei University
36 J Plant Res (2014) 127:23–42
123
Perennial brown algae such as Eisenia bicyclis
(Fig. 12) and Sargassum yamadae (Fig. 13), which are
important elements of algal beds in the area, also showed
similar progressions in 137Cs levels, although the level of40K (ca. 1,500–2,000 Bq kg-1) was generally higher than
in Ulva pertusa (Fig. 11). The 40K levels of Eisenia bi-
cyclis and Sargassum yamadae of the specimens from
Chiba Pref. were 1,650–1,750 and 1,180 Bq kg-1,
respectively, and were comparable to those in Fukushima
Pref. (Figs. 12, 13). Unfortunately, there were few species
of red algae that could be collected seasonally. Ahnfelti-
opsis paradoxa (Suringar) Masuda (Fig. 14) showed a
clear decrease in 137Cs levels in 2011, but it was also still
in a detectable range of ca. 10 Bq kg-1 in March 2013.40K levels were in the range of 800–1,000 Bq kg-1,
which was comparable to Ulva (green alga) and consid-
erably lower than Undaria, Eisenia and Sargassum)
(brown algae).
Discussion
137Cs concentrations in seawater off the eastern Japan coast
prior to the accident were in the same order of magnitude
as other surface oceanic waters, between 1 and 3 Bq m-3
for 137Cs (Nakanishi et al. 2010). After the accident,
measured concentrations in a 30 km perimeter around the
plant exceeded 10 Bq L-1 (or 10,000,000 Bq m-3) (Bailly
du Bois et al. 2012).
The 137Cs levels in seawater at the coast of Iwaki
(Shioyazaki and Nagasaki) one month after the mass dis-
charge of high concentration contaminated water in April
measured ca. 8–10 Bq L-1 in our own measurements
(Fig. 4). These values agree well with the report of Bailly
du Bois et al. (2012). The coast around Shioyazaki and
Nagasaki was estimated to have been exposed up to ca.
60 Bq L-1 for about two weeks (15 April–1 May 2011)
according to the estimated geographical distribution of the137Cs in Bailly du Bois et al. (2012).
The influence of the radioactive liquid effluents escaping
directly from the nuclear power plant was particularly sig-
nificant from 26 March to 8 April 2011 in the vicinity of the
plant. Concentrations measured after 10 April 2011 declined
in the vicinity of the plant. The perennial brown alga Eisenia
bicyclis also showed a similar pattern, but in the red alga
Ahnfeltiopsis paradoxa the levels stayed about the same
during December 2012 and March 2013. In contrast, the
concentration of 40K was relatively stable throughout the
period, in accordance with the assumption that it is not of
anthropogenic origin because the levels were comparable to
those of the specimens from Chiba Pref. and Hyogo Pref.
Given that the seawater 137Cs levels were in the range of
10–60 Bq L-1 at Shioyazaki and Nagasaki in April 2011
[according to our data and those by Bailly du Bois et al.
Fig. 4 Quantities of 134Cs and 137Cs of diverse marine macroalgae
and seawater collected in May 2011 at Nagasaki, Iwaki, Fukushima
Pref., Japan. Measurement unit for seawater is Bq kg-1 (wet weight).
Asterisks show data by the measurement at Iwaki Meisei University
Fig. 5 Quantities of 134Cs and 137Cs of diverse marine macroalgae
collected in July 2011 at Nagasaki, Iwaki, Fukushima Pref., Japan.
Asterisks show data by the measurement at Iwaki Meisei University
J Plant Res (2014) 127:23–42 37
123
Fig. 6 Quantities of 134Cs and 137Cs of diverse marine macroalgae
collected in October 2011 at Nagasaki, Iwaki, Fukushima Pref.,
Japan. Asterisks show data by the measurement at Iwaki Meisei
University
Fig. 7 Quantities of 134Cs and 137Cs of diverse marine macroalgae
collected in July 2012 at Nagasaki, Iwaki, Fukushima Pref., Japan.
Asterisks show data by the measurement at Iwaki Meisei University
Fig. 8 Quantities of 134Cs and 137Cs of diverse marine macroalgae
and seawater collected in December 2012 at Nagasaki, Iwaki,
Fukushima Pref., Japan. Asterisks show data by the measurement at
Iwaki Meisei University
Fig. 9 Quantities of 134Cs and 137Cs of diverse marine macroalgae
and seawater collected in March 2013 at Nagasaki, Iwaki, Fukushima
Pref., Japan
38 J Plant Res (2014) 127:23–42
123
(2012)], and that seaweeds collected in May 2011 con-
tained an average 137Cs level of ca. 5,000 Bq kg-1, the
seaweeds are considered to have accumulated 137Cs in their
tissues by 8–50 folds compared to their environment
(80–500 folds in dry samples, given the wet/dry mass ratio
of 10). These CF values must be certainly underestimated
because some part (or a large part) of the algal tissue of the
specimens collected in early May 2011 (2 May and 6 May
2011) had already been grown up before the exposure to
the highly radiopolluted seawater. In general, the growth
rate of seaweeds differs depending on the species; even in
rather fast growing species, such as Ulva spp. and Undaria
pinnatifida, their growth period is longer than one month;
and many species grow up in 3–4 months.
The above CF values of ca. 8–50 agree well with the
known CF values of ca. 30–50 in marine macroalgae
(IAEA 2004). Considering the underestimation in our data
as mentioned above, macroalgal CF may be somewhat
higher than the IAEA standard. This could be caused if
the local concentration of 137Cs in polluted seawater
during the seaweed growth period (e.g., during later April
2011) were higher than that on the collection dates after
May 2011.
The 137Cs levels of the specimens directly dried after
collection (air-dried and then heated; e.g., k001, k004 in
Table 1), and those frozen before drying (frozen, thawed,
air-dried and then heated; e.g., k017, k023) were roughly
comparable. Meltwater from the frozen algal tissues (k048–
Fig. 10 Evolution of 134Cs, 137Cs and 40K quantities in the annual
green alga Ulva pertusa at Nagasaki, Iwaki, Fukushima Pref., Japan
Fig. 11 Evolution of 134Cs, 137Cs and 40K quantities in the annual
brown alga Undaria pinnatifida at Nagasaki, Iwaki, Fukushima Pref.,
Japan
Fig. 12 Evolution of 134Cs, 137Cs and 40K quantities in the perennial
brown alga Eisenia bicyclis at Nagasaki, Iwaki, Fukushima Pref.,
Japan
Fig. 13 Evolution of 134Cs, 137Cs and 40K quantities in the perennial
brown alga Sargassum yamadae at Nagasaki, Iwaki, Fukushima Pref.,
Japan
J Plant Res (2014) 127:23–42 39
123
k051) contained significantly higher concentrations of 137Cs
compared to the thawed tissue, although the levels were
rather variable depending on the taxa (ca. 40 Bq L-1 in
Undaria pinnatifida to ca. 800 Bq L-1 in Eisenia bicyclis).
The 137Cs concentrations in meltwater was much higher
than that in ambient seawater, which was below the detec-
tion level of ca. 1 Bq L-1 in early July 2011, and was
comparable to that in fresh algal tissues, which was esti-
mated from the present measurements of directly dried
specimens. Thus, we concluded that the measurements
based on dried specimens after the freezing process may
underestimate the 137Cs concentrations in fresh algal tissues.
We showed that the radioactive Cs levels in marine
macroalgae decline rather rapidly during the summer of
2011. This may be ascribed to the fact that the marine
macroalgae grow and turnover rapidly during this period.
The growth periods of a number of annual taxa [e.g.,
Scytosiphon lomentaria, Monostroma nitidum Wittrock,
Ulva spp., Pyropia (Porphyra) spp.] are less than six
months irrespective of their life history patterns (see below;
Fig. 15). Many taxa have life histories with alternation of
heteromorphic sporophytes and gametophytes [e.g., Un-
daria pinnatifida, Scytosiphon lomentaria, Monostroma
nitidum, Pyropia yezoensis (Roth) C. Agardh] and their
macroscopic generations disappear during summer and
autumn (Bold and Wynne 1985; Graham and Wilcox 2000;
Hori 1993, 1994). In these cases, even though the thallus
tissues had absorbed a large amount of radionuclides dur-
ing development (i.e., late March–April 2011), they were
replaced by new tissues, resulting in lower or null radio-
nuclide concentrations before summer and autumn 2011.
Some of the taxa with heteromorphic life history have
perennial macroscopic thalli, and these thalli persist during
summer (e.g., Eisenia bicyclis, Saccharina japonica).
However, they show intercalary growth with a growth zone
in the transitional zone between blade and stipe, and the
older parts of the thalli (blade) become gradually lost from
the tip within several months (Bold and Wynne 1985).
Many others, e.g., Ulva spp., Dictyota dichotoma (Hudson)
J.V. Lamouroux, Spatoglossum crissum J. Tanaka, Chondrus
spp., Gloiopeltis furcate, and Ahnfeltiopsis paradoxa, have
life histories with alternation between isomorphic macro-
scopic generations. However, the growth period of a genera-
tion is generally less than 6 months as mentioned above.
A few taxa, e.g., Codium spp. and Sargassum spp., lack
alternation of generations in their life history. Among
them, Sargassum horneri is a winter-spring annual, and
S. yamadae is a perennial species growing during a spring–
summer term. Therefore, most of the macroalgae (and the
tissues constituting their thalli) collected later than autumn
2011 grew by absorbing ambient nutrients including Cs
Fig. 14 Evolution of 134Cs, 137Cs and 40K quantities in the perennial
red alga Ahnfeltiopsis paradoxa at Nagasaki, Iwaki, Fukushima Pref.,
Japan
Fig. 15 Schematic presentation
of growth period (phenology) of
representative marine
macroalgae at Iwaki and its
vicinity
40 J Plant Res (2014) 127:23–42
123
after a rapid decline of the radionuclide concentrations in
seawater. However, it is noteworthy that the levels of 134Cs as
well as 137Cs have remained more or less stable since winter
2012, and were still detectable in spring 2013 in most marine
macroalgae (ca. 8–140 Bq kg-1 for 137Cs in dried speci-
mens). Considering the CF values of Cs in marine macroalgae,
i.e., 8–50 in our study and 50 in the IAEA report, the 137Cs
level in ambient seawater of marine macroalgae habitats was
considered to have retained at the minimum the level of ca.
0.02–0.3 Bq L-1 (based on CF 50). The detection limit of134Cs and 137Cs in seawater differs remarkably depending on
analytical facilities: ca. 0.0008 Bq L-1, http://www1.kaiho.
mlit.go.jp/KANKYO/press/press20121106.pdf; 0.025 Bq
L-1, http://www.env.go.jp/guide/budget/h25/h25-gaiyo/011.
pdf; and 1.2 Bq L-1, http://radioactivity.nsr.go.jp/ja/
contents/8000/7638/24/278_i_0531.pdf. The concentration
in seawater (0.02–0.3 Bq L-1) is critical for the direct
detection of radionuclides in some analytical facilities.
It has been suggested that marine macroalgal metal
loads can be used as markers to track the geographical
distributions of the metal concentrations in coastal seawa-
ters, e.g., Ulva spp. (Caliceti et al. 2002; Haritonidis and
Malea1999), Undaria pinnatifida (Yamada et al. 2007).
Similarly, the bio-monitoring of coastal 137Cs using sea-
weeds must be very useful because marine macroalgae in
general are shown to avidly accumulate 137Cs in their tis-
sues (CF = ca. 8–50), whereas they grow rather rapidly
and, hence, turnover rapidly, so that they exert no influence
of bioconcentration through the food chain.
Acknowledgments We are grateful to E.C. Henry (Reed Maricul-
ture) for his valuable comments on the manuscript, Chiyo Komiyama
and Tomoko Kotani (Kobe University) for technical support in the
measurements of radionuclides and data analyses, Toshiaki Wada,
Tadashi Iwasaki, Naoto Hirakawa (Fukushima Prefectural Fisheries
Experimental Station), Masataka Ohta (Marine Ecology Research
Institute) and Norio Kikuchi (Natural History Museum and Institute,
Chiba) for assistance in the field collections. The project was sup-
ported by the research grant of Organization of Advanced Science and
Technology, Kobe University.
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