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Little evidence of radiocaesium in the White Sea navaga (Pisces: Eleginus navaga)
Volume 32/Numbers 8/9/August/September 1996
Edited by D. J. H. Phillips
The objective of BASELINE is to publish short communications on different aspects of pollution of the marine environment. Only those papers which clearly identify the quality of the data will be considered for publication. Contributors to Baseline should refer to 'Baseline--The New Format and Content' (Mar. Pollut. Bull. 24, 124). Marine Pollution Bulletin, Vol. 32, Nos 8/9, pp. 689-690, 1996 Copyright © 1996 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0025-326X/96 $15.00 + 0.00
Pergamon
PII: S0025-326X(96)00037-9
Little Evidence of Radiocaesium in the White Sea Navaga (Pisces: Eleginus
navaga)
JORGEN S. CHRISTIANSEN* and HELGE E. BJORNSTAD~'~ *Norwegian Institute of Fisheries and Aquaculture, PB 2511, N-9002 Tromso Norway t The Agricultural University of Norway, PB 5026, N-1432, .4s, Norway :~Present address: Solberg Sand, N-1440 Dr~bak, Norway
Radionuclides such as strontium (9°Sr) and caesium (137Cs) have been discharged regularly into the Eurasian part of the Arctic Ocean for several years (Nilsen & Bohmer, 1994; Sickel et al., 1995). Radioactive sources in this area include waste from nuclear reprocessing and atmospheric fallout. Nuclear-powered submarines and icebreakers may pose a further potential hazard to the environment. Marine resources may be radioactively contaminated as a result, and studies aimed at assessing the impact of radioactive contaminants on biota and sediments have intensified recently (Matishov et al., 1993; Feyn & Sv2eren, 1995). The study sites have included the Barents Sea, the northern coast of the Kola Peninsula, and the waters off Novaya Zemlya, including the Kara Sea. Thus far, the marine biota of these areas have not been found to be markedly affected by anthropogenic radionuclides (Foyn & Sv~eren, 1995). The Barents Sea and adjacent open oceanic waters have been extensively investigated, but there is virtually no published information on biota in the White Sea. This communication provides information concerning 137Cs levels in White Sea navaga (Eleginus navaga) obtained during the course of a joint Norwegian-Russian expedition in April 1993. The city of Severodvinsk (64°35'N, 39°50'E; see Fig. 1) lies on the delta of the River Dvina, close to Archangelsk in the inner part of the Dvina Bay (Dvinskaya Guba). Severodvinsk is potentially a
major source of radioactive contamination in the White Sea, since it has one of the largest shipyards for nuclear-powered submarines in the former Soviet Union, and is a disposal site for military nuclear waste (Nilsen & Bohmer, 1994). The navaga is a small (to 30 cm body length) gadoid fish species which occurs in several local stocks along the coastline of the White Sea (Kriksunov et al., 1992). The navaga of Dvina Bay are commercially important, being exploited for human consumption. In this study, navaga were examined for 137Cs rather than 9°Sr, because caesium is primarily deposited in the soft edible parts of the fish and is therefore relevant to human health. Navaga were caught near Jagry Island on the outskirts of Severodvinsk (Christiansen et al., 1995), and 14 fish were examined. The fish were aged from otolith readings, and whole individuals were freeze-dried and analysed for proximate body composition (Hopkins et al., 1984). Ground, homogenized samples were transferred into 20 ml plastic counting vials. The content of radiocaesium in each fish was measured using a Minaxi 5000 Auto-Gamma Analyser with a through-holed NaI detector, (Packard International S. A. Illinois, USA). The decision and lower limit for detection were 91 mBq and 203 mBq, respectively, according to Currie (1968). The results are shown in Table 1. The age of the navaga analysed varied from 5 to 8 yr. All fish were in good condition and had been feeding on zoobenthos, fish and demersal egg clusters of the White Sea herring, Clupea harengus. Radiocaesium could not be detected in most of the navaga (n= 11), but three individuals exhibited low levels of 137Cs (less than 8.4-10.7 Bq kg -1 dry weight or 2.4-2.7 Bq kg -1 wet weight; see Table 1). This level may be somewhat higher than reported for cod, Gadus morhua, in the Barents Sea (0.7 Bq k g - 1 wet weight), but is considerably lower than the 137Cs concentrations found in Baltic Sea cod (21 Bq kg -1 wet weight; see Sickel et aL, 1995). The navaga is deemed to be an efficient indicator of radioactive contamination within a limited geographic area since it is relatively long-living, feeds on bottomdwelling animals and undergoes only small-scale migrations. Although present data are few, they suggest that only a small number of the fish examined (~21%) were radiocontaminated and the 137Cs levels found do not pose any risk to consumers according to international agreements (Sickel et al., 1995). However, one should bear in mind the potential for radioactive leakages, and the present situation may alter quickly where nuclear waste disposal occurs in an uncontrolled fashion.
We wish to thank Professor A. G. Chernitsky, Dr O. V. Karamushko and Professor Malcolm Jobling for their contributions to this study and the Barents Secretariate for financial support.
689
Marine Pollution Bulletin
/
V
l
GB
t2"" t l
Fig. 1 Location map showing the northern part of Fennoscandia and northwest Russia and the sampling site for uavaga (filled circle) within the White Sea. A=Archangelsk; DG=Dvina Bay; GB = Gulf of Bothnia; RD = River Dvina; S = Severodvinsk. TABLE I Proximate body composition and 137CS content of White Sea navaga in April 1993. Data for non-contaminated fish are pooled and the ranges in values are shown in parentheses. Data for radiocontaminated fish are shown for each individual (n = 3). Non-contaminated Age (yr) Body weight (g) Body length (ram) Dry matter (% body weight) Protein (% dry weight) Lipid (% dry weight) Stomach content (% body weight) Radiocaesium (Bq kg -1 dry weight)
6.3 (5-8) 55.5 (32.9-99.3) 190.3 (165-231) 31.5 (25.3-36.9) 49.8 (46.1-53.4) 16.3 (13.8-19.4) 3.4 (0.6--8.2) nd
Radiocontaminated 6 54.3 180 28.4 50.3 16.3 14.5 8.4
5 83.4 219 27.1 50.2 15.7 4.6 9.5
7 94.3 235 25.6 47.9 16.2 3.5 10.7
nd = Non-detectable. Christiansen, J. S., Chemitsky, A. G. & Karamushko, O. V. (1995). An Arctic teleost fish with a noticeably high body fluid osmolality: a note on the uavaga, Eleginus navaga (Pallas 181 I), from the White Sea. Polar BioL 15, 303-306. Currie, L. A. (1968). Limits for qualitative detection and quantitative determination. Application to radioehernistry. Anal. Chem. 40, 586593. F~yn, L. & Svaeren, I. (1995). Distribution and sedimentation of radionuclides in the Barents Sea. ICES CM 1995/Mini: 11. International Council for the Exploration of the Seas, Copenhagen. Hopkins, C. C. E., Seiring, J. V., Nyholmen, O. & Hermausen, A. (1984). Ecological energetics from total lipid and total protein: fact and artifact using a gravimetric method for lipid and biuret method for protein. Ocean. Mar. BioL Ann. Rev. 22, 211-251.
690
Kriksunov, E. A., Stasenkov, V. A., Naimark, E. B. & Karpov, A. K. (1992). Population dynamics of the White Sea navaga Eleginus navaga. Vopr. lkhtiol. 32, 94-100. Matishov, D. G., Matishov, G. G., Szczypa, E. & Pavlova, L.G. (1993). New data on radionuclide content in the Barents Sea and on the shore. Doklady Akademii Nauk 332, 118-119. Nilsen, T. & Bvhmer, N. (1994). Sources to radioactive contamination in Murmansk and Archangelsk counties. Bellona rapport 1994: 1, Milj~stiftelsen Bellona, PB 8874, Youngstorget, N-0028 Oslo, Norway. Sickel, M. A. K., Selnaes, T. D., Christeusen, G. C., Bee, B., Strand, P. & Hellstrem, T. (1995). Radioactivity in the marine environment: report from the national surveillance programme. StrhlevernRapport 1995: 1, Norwegian Radiation Protection Authority, PB 55, N1345 Oster'~s, Norway.
Edited by D. J. H. Phillips
The objective of BASELINE is to publish short communications on different aspects of pollution of the marine environment. Only those papers which clearly identify the quality of the data will be considered for publication. Contributors to Baseline should refer to 'Baseline--The New Format and Content' (Mar. Pollut. Bull. 24, 124). Marine Pollution Bulletin, Vol. 32, Nos 8/9, pp. 689-690, 1996 Copyright © 1996 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0025-326X/96 $15.00 + 0.00
Pergamon
PII: S0025-326X(96)00037-9
Little Evidence of Radiocaesium in the White Sea Navaga (Pisces: Eleginus
navaga)
JORGEN S. CHRISTIANSEN* and HELGE E. BJORNSTAD~'~ *Norwegian Institute of Fisheries and Aquaculture, PB 2511, N-9002 Tromso Norway t The Agricultural University of Norway, PB 5026, N-1432, .4s, Norway :~Present address: Solberg Sand, N-1440 Dr~bak, Norway
Radionuclides such as strontium (9°Sr) and caesium (137Cs) have been discharged regularly into the Eurasian part of the Arctic Ocean for several years (Nilsen & Bohmer, 1994; Sickel et al., 1995). Radioactive sources in this area include waste from nuclear reprocessing and atmospheric fallout. Nuclear-powered submarines and icebreakers may pose a further potential hazard to the environment. Marine resources may be radioactively contaminated as a result, and studies aimed at assessing the impact of radioactive contaminants on biota and sediments have intensified recently (Matishov et al., 1993; Feyn & Sv2eren, 1995). The study sites have included the Barents Sea, the northern coast of the Kola Peninsula, and the waters off Novaya Zemlya, including the Kara Sea. Thus far, the marine biota of these areas have not been found to be markedly affected by anthropogenic radionuclides (Foyn & Sv~eren, 1995). The Barents Sea and adjacent open oceanic waters have been extensively investigated, but there is virtually no published information on biota in the White Sea. This communication provides information concerning 137Cs levels in White Sea navaga (Eleginus navaga) obtained during the course of a joint Norwegian-Russian expedition in April 1993. The city of Severodvinsk (64°35'N, 39°50'E; see Fig. 1) lies on the delta of the River Dvina, close to Archangelsk in the inner part of the Dvina Bay (Dvinskaya Guba). Severodvinsk is potentially a
major source of radioactive contamination in the White Sea, since it has one of the largest shipyards for nuclear-powered submarines in the former Soviet Union, and is a disposal site for military nuclear waste (Nilsen & Bohmer, 1994). The navaga is a small (to 30 cm body length) gadoid fish species which occurs in several local stocks along the coastline of the White Sea (Kriksunov et al., 1992). The navaga of Dvina Bay are commercially important, being exploited for human consumption. In this study, navaga were examined for 137Cs rather than 9°Sr, because caesium is primarily deposited in the soft edible parts of the fish and is therefore relevant to human health. Navaga were caught near Jagry Island on the outskirts of Severodvinsk (Christiansen et al., 1995), and 14 fish were examined. The fish were aged from otolith readings, and whole individuals were freeze-dried and analysed for proximate body composition (Hopkins et al., 1984). Ground, homogenized samples were transferred into 20 ml plastic counting vials. The content of radiocaesium in each fish was measured using a Minaxi 5000 Auto-Gamma Analyser with a through-holed NaI detector, (Packard International S. A. Illinois, USA). The decision and lower limit for detection were 91 mBq and 203 mBq, respectively, according to Currie (1968). The results are shown in Table 1. The age of the navaga analysed varied from 5 to 8 yr. All fish were in good condition and had been feeding on zoobenthos, fish and demersal egg clusters of the White Sea herring, Clupea harengus. Radiocaesium could not be detected in most of the navaga (n= 11), but three individuals exhibited low levels of 137Cs (less than 8.4-10.7 Bq kg -1 dry weight or 2.4-2.7 Bq kg -1 wet weight; see Table 1). This level may be somewhat higher than reported for cod, Gadus morhua, in the Barents Sea (0.7 Bq k g - 1 wet weight), but is considerably lower than the 137Cs concentrations found in Baltic Sea cod (21 Bq kg -1 wet weight; see Sickel et aL, 1995). The navaga is deemed to be an efficient indicator of radioactive contamination within a limited geographic area since it is relatively long-living, feeds on bottomdwelling animals and undergoes only small-scale migrations. Although present data are few, they suggest that only a small number of the fish examined (~21%) were radiocontaminated and the 137Cs levels found do not pose any risk to consumers according to international agreements (Sickel et al., 1995). However, one should bear in mind the potential for radioactive leakages, and the present situation may alter quickly where nuclear waste disposal occurs in an uncontrolled fashion.
We wish to thank Professor A. G. Chernitsky, Dr O. V. Karamushko and Professor Malcolm Jobling for their contributions to this study and the Barents Secretariate for financial support.
689
Marine Pollution Bulletin
/
V
l
GB
t2"" t l
Fig. 1 Location map showing the northern part of Fennoscandia and northwest Russia and the sampling site for uavaga (filled circle) within the White Sea. A=Archangelsk; DG=Dvina Bay; GB = Gulf of Bothnia; RD = River Dvina; S = Severodvinsk. TABLE I Proximate body composition and 137CS content of White Sea navaga in April 1993. Data for non-contaminated fish are pooled and the ranges in values are shown in parentheses. Data for radiocontaminated fish are shown for each individual (n = 3). Non-contaminated Age (yr) Body weight (g) Body length (ram) Dry matter (% body weight) Protein (% dry weight) Lipid (% dry weight) Stomach content (% body weight) Radiocaesium (Bq kg -1 dry weight)
6.3 (5-8) 55.5 (32.9-99.3) 190.3 (165-231) 31.5 (25.3-36.9) 49.8 (46.1-53.4) 16.3 (13.8-19.4) 3.4 (0.6--8.2) nd
Radiocontaminated 6 54.3 180 28.4 50.3 16.3 14.5 8.4
5 83.4 219 27.1 50.2 15.7 4.6 9.5
7 94.3 235 25.6 47.9 16.2 3.5 10.7
nd = Non-detectable. Christiansen, J. S., Chemitsky, A. G. & Karamushko, O. V. (1995). An Arctic teleost fish with a noticeably high body fluid osmolality: a note on the uavaga, Eleginus navaga (Pallas 181 I), from the White Sea. Polar BioL 15, 303-306. Currie, L. A. (1968). Limits for qualitative detection and quantitative determination. Application to radioehernistry. Anal. Chem. 40, 586593. F~yn, L. & Svaeren, I. (1995). Distribution and sedimentation of radionuclides in the Barents Sea. ICES CM 1995/Mini: 11. International Council for the Exploration of the Seas, Copenhagen. Hopkins, C. C. E., Seiring, J. V., Nyholmen, O. & Hermausen, A. (1984). Ecological energetics from total lipid and total protein: fact and artifact using a gravimetric method for lipid and biuret method for protein. Ocean. Mar. BioL Ann. Rev. 22, 211-251.
690
Kriksunov, E. A., Stasenkov, V. A., Naimark, E. B. & Karpov, A. K. (1992). Population dynamics of the White Sea navaga Eleginus navaga. Vopr. lkhtiol. 32, 94-100. Matishov, D. G., Matishov, G. G., Szczypa, E. & Pavlova, L.G. (1993). New data on radionuclide content in the Barents Sea and on the shore. Doklady Akademii Nauk 332, 118-119. Nilsen, T. & Bvhmer, N. (1994). Sources to radioactive contamination in Murmansk and Archangelsk counties. Bellona rapport 1994: 1, Milj~stiftelsen Bellona, PB 8874, Youngstorget, N-0028 Oslo, Norway. Sickel, M. A. K., Selnaes, T. D., Christeusen, G. C., Bee, B., Strand, P. & Hellstrem, T. (1995). Radioactivity in the marine environment: report from the national surveillance programme. StrhlevernRapport 1995: 1, Norwegian Radiation Protection Authority, PB 55, N1345 Oster'~s, Norway.