Framvaren fjord

Figure 7.8 Water column profiles of (a) dissolved organic carbon (DOC) and (b) values (particulate uranium/dissolved uranium) across the redox transition in the stratified Framvaren fjord (Norway). (Modified from Swarzenski et al., 1999.)...

McKee, B.A., and Skei, J. (1999) Framvaren Fjord as a natural laboratory for examining biogeochemical processes in anoxic environments. Mar. Chem. 67, 147-148. 

Todd, J.F., Elsinger, R.J., and Moore, W.S. (1988) The distributions of uranium, radium, and thorium isotopes in two anoxic fjords Framvaren Fjord (Norway) and Saanich Inlet (British Columbia). Mar. Chem. 23, 393—415. 

Jacobs L., Emerson S., and Skei J. (1985) Partitioning and transport of metals across the O2/H2S interface in a permanently anoxic basin Framvaren Fjord, Norway. Geochim. Cosmochim. Acta 49, 1433—1444. 

Keith-Roach, M. J., and Roos, P. (2004). Redox-dependent behaviour of technetium-99 entering a permanently stratified anoxic fjord (Framvaren fjord, Norway). Estuar. Coast. Shelf Sci. 60, 151-161. 

Vertical distributions of dissolved Ba and total (dissolved+particulate) Pu, Am and Th in Framvaren Fjord all show increased concentrations with depth (Falkner etal., 1993 Roos etal., 1993). Ba cycling was dominated by its uptake into particulate matter associated with productivity in surface waters, followed by its regeneration at depth or in the sediments. Microbiological activity near the redox interface likely promotes the breakdown of settling particulate matter and the release of barite just above the 02/H2S interface (Falkner etal., 1993). Complex formation with dissolved organic carbon (DOC) is believed to be the main cause for the observed behavior of Pu, Am and Th (Roos etal., 1993). The distributions of these elements were not examined within the regions near the 02/H2S interface and the associated microbial layer. 

H2S interface (Swarzenski etal., 1999b). Such concentration maxima at the redox boundary is also observed for DOC, Sr and Ba. The authors hypothesize that the source of elevated U at the redox boundary must be due to microbial uptake and subsequent release processes. Uranium oxidation state determinations in waters from 1, 22 and 30 m depth reveal that reduced U(IV) is not present in significant abundance, and that the chemical and/or biological reduction of hexavalent uranium is largely inhibited. These results suggest that U, DOC, Sr, Ba, Fe(II), and Mn(II) are greatly modified by direct and indirect microbial transformation reactions which are most concentrated across the redox transition zone in Framvaren Fjord. 

Cutter, G.A. and Kluckhohn, R.S. (1999) The cycling of particulate carbon, nitrogen, sulfur, and sulfur species (iron monosulfide, greigite, pyrite, and organic sulfur) in the water columns of Framvaren Fjord and the Black Sea. Marine Chemistry, 67, 149-160. 

Dyrssen, D.W. (1997) The source of silica and trace metals in particulate matter in Framvaren fjord. 

Mandernack, K.W. and Tebo, B.M. (1999) In situ sulfide removal and C02 fixation rates at deep-sea hydrothermal vents and the oxic/anoxic interface in Framvaren Fjord, Norway. Marine Chemistry, 66, 201-213. 

Shapiro, S.D., Schlosser, P., Smethie, W.M. and Stute, M. (1997) The use of H-3 and tritiogenic He-3 to determine CFC degradation and vertical mixing rates in Framvaren Fjord, Norway. Marine Chemistry, 59, 141—157. 

Velinsky, D.J. and Fogel, M.L. (1999) Cycling of dissolved and particulate nitrogen and carbon in the Framvaren Fjord, Norway stable isotopic variations. Marine Chemistry, 67, 161—180. 

Wensheng, Y. and Millero, F.J. (1995) The chemistry of the anoxic waters in the Framvaren Fjord, Norway. Aquatic Geochemistry, 1, 53-88. 

---