A combined study involving lamina counting, 210Pb and the fallout- 137Cs dating techniques were used to date two sediment cores with intact sediment-water interfaces from the anoxic fjord Nordåsvannet. Averaged sedimentation rates, determined from radiometric measurements, range from 0.4 to 2.1mm yr-1 over the core with a higher rate at the top. The available lamina data support the sedimentation rate estimates made from radiometric measurements.
An increase was found in trace-metal concentrations (Zn: 90-807 ppm ; Cu: 30-176 ppm and Pb: 40-225 ppm) and mass accumulation rates (MAR; Zn: 0.003-0.10 g m2 yr -1, Cu: 0.001-0.02 g m2 yr-1 and Pb: 0.002-0.02 g m2 yr-1) across the upper 5 cm of the sediments. This increase coincides with the introduction of sewage effluent through two deep outlets at 40m water depth into the fjord at Fjøsanger and Skjold in 1969. The MAR suggest that the enhanced sewage supply has caused the metal enrichment in the Nordåsvannet bottom sediments after 1969.
Alve, E.1991: Foraminifera, climatic change, and pollution: a study of late Holocene sediments in Drammensfjord, southeast Norway. The Holocene1(3), 243-61.
2.
Anderson, R.Y., Hemphill-Haley, E. and Gardner, J.V.1987a: Persistent Late Pleistocene-Holocene seasonal upwelling and varves off the Coast of California. Quaternary Research28, 307-13.
3.
Anderson, R.F., Schiff, S.L. and Hesslein, R.H.1987b: Determining sediment accumulation and mixing rates using 210Pb, 137Cs, and other tracers: problems due to post-depositional mobility or coring artifacts. Canadian Journal of Fisheries and Aquatic Sciences44(1), 231-50.
4.
Appleby, P.G., Richardson, N., Nolan, P.J. and Oldfield, F.1990: Radiometric dating of the United Kingdom SWAP sites . Philosophical Transactions of the Royal SocietyLondon B 327, 233-38.
5.
Baumgartner, T., Ferreira-Bartrina, V., Schrader, H. and Soutar, A.1985: A 20-year varve record of siliceous phytoplankton variability in the central Gulf of California. Marine Geology64, 113-29.
6.
Braarud, T. and Hope, B.1952: The annual phytoplankton cycle of a landlocked fjord near Bergen (Nordåsvatn). Fiskeridirektoratets Skrifter, Serie Havundersøkelser9(16), 5-26.
7.
Cato, I.1990: Sedimentological investigations of Brofjorden with particular reference to Trommekilen 1989 and changes after 1972 and 1984. Sveriges Geologiska Undersöking (Uppsala, Sweden), Rapporter och Meddelanden64, 75 pp.
8.
Chesselet, R. and Lalou, C.1988: The use of natural radionuclides in oceanography: an overview . In Guary, J.C., Guegueniat, P. and Pentreath, R.J., editors, Radionuclides: a tool for oceanography. London: Elsevier Applied Science, 1-11.
9.
Colley, S. and Thomson, J.1991: Nuclear science and technology: migration of uranium daughter radionuclides in natural sediments. Commission of the European Communities, Final Report, Luxembourg, 64 pp.
10.
Collier, R. and Edmond, J.1984: The trace element geochemistry of marine biogenic particulate matter. Progress in Oceanography13, 113-99.
11.
Comans, R.N.J. and Hockley, D.E.1992: Kinetics of cesium sorption on illite. Geochimica et Cosmochimica Acta56, 1157-64.
12.
Comans, R.N.J., Middleburg, J.J., Zonderhuis, J., Woittiez, J.R.W., de Lange, G.J., Das, H.A. and van der Weijden, C.H.1989: Mobilization of radiocaesium in pore water of lake sediments. Nature339, 367-69.
13.
Crusius, J. and Anderson, R.F.1992: Inconsistencies in accumulation rates of Black Sea sediments inferred from records of laminae and 210Pb. Paleoceanography7(2), 215-27.
14.
Donegan, D. and Schrader, H.1982: Biogenic and abiogenic components of laminated hemipelagic sediments in the central Gulf of California. Marine Geology48, 215-37.
15.
Dymond, J. and Veeh, H.1975: Metal accumulation rates in the southeast Pacific and the origin of metalliferous sediments. Earth Planetary Science Letters28, 13-22.
16.
Egeberg, P.K.1983: A geochemical survey of sediments and pore waters from the inner Oslofjord. Unpublished PhD thesis, University of Oslo.
17.
Finney, P.B. and Huh, C.-A.1989: History of metal pollution in the Southern California Bight: an update. Environmental Science Technology. 23(3), 294-303.
18.
Gaarder, T.1916: De Vestlandske fjorders hydrografi. I. Surtstoff i fjordene. Bergens Museums Aarbok 1915-1916, Naturvidenskapelig Rœkke2, 7-190.
19.
Glenne, B. and Simensen, T.1963: Tidal choking in the landlocked fjord of Nordåsvannet . Sarsia11, 43-73.
20.
Heggie, D.T.1983: Copper in the Resurrection Fjord, Alaska. Estuarine, Coastal and Shelf Science17, 613-35.
21.
Juillet-Leclerc, A. and Schrader, H.1987: Variations of upwelling intensity recorded in varved sediments from the Gulf of California during the past 3000 years. Nature329, 146-49.
22.
Koide, M., Bruland, K.W. and Goldberg, E.D.1973: Th-228/Th-232 and Pb-210 geochronologies in marine and lake sediments. Geochimica et Cosmochimica Acta37, 1171-87.
23.
Larsen, B. and Pheiffer Madsen, P.1986: Heavy metal budgets for selected Danish sea areas. Rapports et Procès-Verbeaux Conseil International pour l'Exploration de la Mer186, 244-50.
24.
Martin, J.H. and Knauer, A.1973: The elemental composition of plankton. Geochimica et Cosmochimica Acta37, 1639-53.
25.
Mélière, M.A., Pourchet, M., Pinglot, J.F., Bouchez, R. and Piboule, M.1988: Chernobyl 134Cs, 137Cs, and 210Pb in high mountain lake sediments: measurements and modelling of mixing processes. Journal of Geophysical Research93(D6), 7055-7061.
26.
Mosby, H. and Vogelsang, T.M.1949: Sjøbadene i Bergen. Bakteriologiske og hydrografiske undersøkelser 1948. Bergen: A.s John Griegs Boktrykkeri , 4-21.
27.
Munda, I.1967: Observations on the benthic marine algae in a landlocked fjord (Nordåsvannet) near Bergen, Western Norway. Nova Hedwigia14(2-4), 519-48.
28.
Nagy, J. and Alve, E.1987: Temporal changes in foraminiferal faunas and impact of pollution in Sandebukta, Oslofjord. Marine Micro-palaeontology12, 109-28.
29.
Niemistö, L.1974: A gravity corer for studies of soft sediments. Meretutkimuslait238, 33-38.
30.
Norton, S.A.1986: A review of the chemical record in lake sediment of energy related air pollution and its effects on lakes. Water, Air and Soil Pollution30, 331-45.
31.
Norton, S.A. and Hess, C.T.1980: Atmospheric deposition in Norway during the last 300 years as recorded in SNSF lake sediments. I, Sediment dating and chemical stratigraphy . In Drabløs, D. and Tollan, A., editors, Ecological impact of acid precipitation. Proceedings of an international conference, Sandefjord, Norway, March 11-14 1980, 268-69.
32.
Paetzel, M. and Schrader, H.1991: Heavy metal (Zn, Cu, Pb) accumulation in the Barsnesfjord: western Norway. Norsk Geologisk Tidsskrift71, 65-73.
33.
Paetzel, M. and Schrader, H.1992: Recent environmental changes recorded in anoxic Barsnesfjord sediments: western Norway. Marine Geology105, 23-36.
34.
Pennington, W., Tutin, G.W., Cambray, R.S. and Fisher, E.M.1973: Observations on lake sediments using fallout 137Cs as a tracer. Nature141,324-26.
35.
Pentreath, R.J.1988: Sources of artificial radionuclides in the marine environment . In Guary, J.C., Guegueniat, P. and Pentreath, R.J., editors, Radionuclides: a tool for oceanography. London: Elsevier Applied Science, 12-34.
36.
Pheiffer Madsen, P. and Sørensen, J.1979: Validation of the lead-210 dating method. Journal of Radioanalytical Chemistry54, 39-48.
37.
Prandle, D. and Beechey, J.1991: The dispersal of 137Cs from Sellafield and Chernobyl in the NW European shelf seas. In Kershaw, P.J. and Woodhead, D.S., editors, Radionuclides in the study of marine processes. London : Elsevier Applied Science, 84-93.
38.
Ravndal, F.1971: Studier omkring eksisterende dyputslipp i Nordåsvatn, Fana kommune. Oslo: Norsk Institutt for Vannforskning.
39.
Sancetta, C. and Calvert, S.E.1988: The annual cycle of sedimentation in Saanich Inlet , British Columbia: Implications for the interpretation of diatom fossil assemblages. Deep-Sea Research35, 71-90.
40.
Schafer, C.T., Smith, J.N. and Côté, R.1990: The Saguenay Fiord: a major tributary to the St Lawrence Estuary. In El-Sabh, M.I. and Silverberg, N., editors, Oceanography of a large scale estuarine system. The St Lawrence Coastal and Estuarine Studies39, Chapter 17, 378-420.
41.
Schimmelmann, A., Lange, C.B., Berger, W.H., Simon, A., Burke, S.K. and Dunbar, R.B.1992: Extreme climatic conditions recorded in Santa Barbara Basin laminated sediments: The 1835-1840 Macoma event. Marine Geology106, 279-99.
42.
Schmidt, H. and Reimers, C.E.1991: The recent history of trace metal accumulation in the Santa Barbara Basin, Southern California Borderland. Estuarine, Coastal and Shelf Science33, 485-500.
43.
Skei, J.M.1983: Geochemical and sedimentological consideration of a permanently anoxic fjord - Framvaren, south Norway. Sedimentary Geology36, 131-45.
44.
Skei, J. and Melsom, S.1982: Seasonal and vertical variation in the chemical composition of suspended particulate matter in an oxygen-deficient fjord. Estuarine, Coastal and Shelf Science14, 61-78.
45.
Skei, J. and Paus, P.E.1979: Surface metal enrichment and partitioning of metals in a dated sediment core from a Norwegian fjord. Geochimica et Cosmochimica Acta43, 239-46.
46.
Skei, J.M., Loring, D.H. and Rantala, R.T.T.1988: Partitioning and enrichment of trace metals in a sediment core from Framvaren, south Norway. Marine Chemistry23, 269-81.
47.
Smith, J.N. and Schafer, C.T.1987: A 20th-century record of climatologically modulated sediment accumulation rates in a Canadian fjord. Quaternary Research27, 232-47.
48.
Suess, E. and Erlenkeuser, H.1975: History of metal pollution and carbon input in Baltic Sea sediments. Meyniana27, 63-75.
49.
Syvitski, J.P.M., Burrell, D.C. and Skei, J.M.1987: Fjords: processes and products. New York: Springer Verlag.
50.
Svensson, N.-O.1989: Late Weichselian and early Holocene shore displacement in the central Baltic, based on stratigraphical and morphological records from eastern Småland and Gotland, Sweden. Unpublished PhD thesis, Lund University, Sweden.
51.
Wan, G.J., Santschi, P.H., Sturm, M., Farrenkothen, K., Lueck, A., Werth, E. and Schuler, Ch.1987: Natural (210Pb, 7Be) and fallout (137Cs, 239,240Pu, 90Sr) radionuclides as geochemical tracers of sedimentation in Greifensee, Switzerland. Chemical Geology63, 181-96.
52.
Wassmann, P.1985: Sedimentation of particulate material in Nordåsvannet, a hypertrophic, land-locked fjord in western Norway. Marine Ecology-Progress Series22, 259-71.
53.
Wassmann, P., Naas, K.E. and Johannessen, P.J.1986: Annual supply and loss of particulate organic carbon in Nordåsvannet, a eutrophic, land-locked fjord in western Norway. Rapports et Procès-Verbeaux Conseil International pour l'Exploration de la Mer186, 423-31.
54.
Westerlund, S., Anderson, L., Hall, P., Iverfeldt, A., Rutgers van der Loeff, M.M. and Sundby, B.1986: Benthic fluxes of cadmium, copper, nickel, zinc, and lead in the coastal environment. Geochimica et Cosmochimica Acta50, 1289-96.
55.
Wiborg, K.F.1944: The production of zooplankton in a landlocked fjord . Fiskeridirektoratets Skrifter, Serie Havundersøkelser7, 1-83.
