Halemann et at.: Dissolved and Particulate Major and Trace Elements
107
(Nolting et aI., 1996; Holemann et aI., subm.). Compared to natural background values for
marine coastal sediments (Chester, 1990) the ice-rafted sediments (IRS) show no indication for
anthropogenic metal enrichment. Contents for Zn and Cd are higher than the median suspended
matter and sediment contents that were measured during the expeditions Transdrift I-III
(HOIemann, unpubl. data), but close to the published world average contents for river
particulate material (Chester, 1990). Elevated cadmium contents of more than 0.027 llmol g-! in
suspended matter were also recorded near the Lena river delta in summer 1994 (Trans drift II).
Especially the Zn and Cd content of newly formed ice north off the Lena delta suggest that
riverine particulate matter from the Tumatskaya branch is the main source for IRS at Stations
291 and 292.
High particle contents in ice from Stations 291 and 292 are associated with high
concentrations of dissolved metals, e.g. Fe, Mn, Cd, Zn and Pb. Comparing the median to
average concentrations measured in the Lena river water (Table 2) the approximate enrichment
factors within the dissolved phase are: 7-25 (Fe), 7 (Mn), 15-30 (Cd), 30-90 (Zn) and 6-40
(Pb). Cu and Ni are only enriched by a factor of 2. Ice from other regions in the Laptev Sea
shows a depletion in Fe, Mn, Pb, Cu and Ni. Dissolved metal concentrations as high as the
concentrations found in the newly formed ice are only known from polluted rivers like the
Rhine (Salomons and Forstner, 1984). The observed high metal concentrations in new ice near
the Tumatskaya branch - with no industrial discharge nearby - can only be explained by
remobilization processes from the particulate phase within the ice.
Table 2: Dissolved « 0.4 ~m) concentrations of Fe, Mn, Cd, Zn, Pb, Cu and Ni in newly fonned ice, water of
the Lena river, and the water column at Station 291, north off the Tumatskaya branch (Lena river). Dissolved
concentrations given for ice samples are median values.
Fe
Mn
Cd
Zn
Ph
Cn
Ni
nmol'kg-] nmol'kg- I nmol'kg- I nmol'kg- I nmol'kg-] nmol'kg- I nmol'kg- I
Lena river water
410
0.037-0.07
5.4
0.08
9.4
5.1
(Martin et a!., 1993)
Lena river water
1494
99.3
15.4
0.51
]1.9
5.9
(Transdrift III,
Station 41H)
Water column
428
52.0
9.7
0.23
6.5
8.2
at Station 29]
(2m, salinity = 29.1)
Ice at Stations 291
10585
706
1.09
479.1
3.08
17.03
10.94
and 292
5497
317
0.67
353
1.91
11.3
7.3
(n=9)
(n=9)
(n=7)
(n=9)
(n=9)
(n=9)
(n=9)
Ice all other stations
281
51.9
0.44
47.7
0.20
4.93
4.56
143
23
0.08
28
0.06
1.22
2.38
(n=IO)
(n=10)
(n=6i
(n= 1Oi
(n=10)
(n=IO)
(n=10)
New ice formation and trace metal cycling
Highest particle contents in newly formed ice (gray ice and gray-white ice) were found north
off the Lena delta near the freshwater outflow of the Tumatskaya branch. The median value for
the relative particle content in ice from this region was 148.9 mg kg-! (Lindemann et aI., this
volume). The maximum particle content in ice from this region analyzed in this study was 250
mg kg-I. Higher relative contents of particulate Zn, S and Cd and lower contents of As together
with the isotopic signature of the ice suggest that the ice bound particles north off the
Tumatskaya branch are of riverine origin. This is supported by the observation that formation
of frazil ice and subsequent incorporation of suspended matter is most intensive at the contact
107
(Nolting et aI., 1996; Holemann et aI., subm.). Compared to natural background values for
marine coastal sediments (Chester, 1990) the ice-rafted sediments (IRS) show no indication for
anthropogenic metal enrichment. Contents for Zn and Cd are higher than the median suspended
matter and sediment contents that were measured during the expeditions Transdrift I-III
(HOIemann, unpubl. data), but close to the published world average contents for river
particulate material (Chester, 1990). Elevated cadmium contents of more than 0.027 llmol g-! in
suspended matter were also recorded near the Lena river delta in summer 1994 (Trans drift II).
Especially the Zn and Cd content of newly formed ice north off the Lena delta suggest that
riverine particulate matter from the Tumatskaya branch is the main source for IRS at Stations
291 and 292.
High particle contents in ice from Stations 291 and 292 are associated with high
concentrations of dissolved metals, e.g. Fe, Mn, Cd, Zn and Pb. Comparing the median to
average concentrations measured in the Lena river water (Table 2) the approximate enrichment
factors within the dissolved phase are: 7-25 (Fe), 7 (Mn), 15-30 (Cd), 30-90 (Zn) and 6-40
(Pb). Cu and Ni are only enriched by a factor of 2. Ice from other regions in the Laptev Sea
shows a depletion in Fe, Mn, Pb, Cu and Ni. Dissolved metal concentrations as high as the
concentrations found in the newly formed ice are only known from polluted rivers like the
Rhine (Salomons and Forstner, 1984). The observed high metal concentrations in new ice near
the Tumatskaya branch - with no industrial discharge nearby - can only be explained by
remobilization processes from the particulate phase within the ice.
Table 2: Dissolved « 0.4 ~m) concentrations of Fe, Mn, Cd, Zn, Pb, Cu and Ni in newly fonned ice, water of
the Lena river, and the water column at Station 291, north off the Tumatskaya branch (Lena river). Dissolved
concentrations given for ice samples are median values.
Fe
Mn
Cd
Zn
Ph
Cn
Ni
nmol'kg-] nmol'kg- I nmol'kg- I nmol'kg- I nmol'kg-] nmol'kg- I nmol'kg- I
Lena river water
410
0.037-0.07
5.4
0.08
9.4
5.1
(Martin et a!., 1993)
Lena river water
1494
99.3
15.4
0.51
]1.9
5.9
(Transdrift III,
Station 41H)
Water column
428
52.0
9.7
0.23
6.5
8.2
at Station 29]
(2m, salinity = 29.1)
Ice at Stations 291
10585
706
1.09
479.1
3.08
17.03
10.94
and 292
5497
317
0.67
353
1.91
11.3
7.3
(n=9)
(n=9)
(n=7)
(n=9)
(n=9)
(n=9)
(n=9)
Ice all other stations
281
51.9
0.44
47.7
0.20
4.93
4.56
143
23
0.08
28
0.06
1.22
2.38
(n=IO)
(n=10)
(n=6i
(n= 1Oi
(n=10)
(n=IO)
(n=10)
New ice formation and trace metal cycling
Highest particle contents in newly formed ice (gray ice and gray-white ice) were found north
off the Lena delta near the freshwater outflow of the Tumatskaya branch. The median value for
the relative particle content in ice from this region was 148.9 mg kg-! (Lindemann et aI., this
volume). The maximum particle content in ice from this region analyzed in this study was 250
mg kg-I. Higher relative contents of particulate Zn, S and Cd and lower contents of As together
with the isotopic signature of the ice suggest that the ice bound particles north off the
Tumatskaya branch are of riverine origin. This is supported by the observation that formation
of frazil ice and subsequent incorporation of suspended matter is most intensive at the contact