, Volume 677, Issue 1, pp 129–148 | Cite as

Nutrient speciation and hydrography in two anchialine caves in Croatia: tools to understand iodine speciation

  • Vesna ŽicEmail author
  • Victor W. Truesdale
  • Vlado Cuculić
  • Neven Cukrov


Despite iodine being one of the most abundant of the minor elements in oxic seawater, the principal processes controlling its interconversion from iodate to iodide and vice versa, are still either elusive or largely unknown. The two major hypotheses for iodate reduction involve either phytoplankton growth in primary production, or bacteria during regeneration. An earlier study intended to exploit the unusual nature of anchialine environments revealed that iodide is oxidised to iodate in the bottom of such caves, whereas reduction of iodate occurs in the shallower parts of the water column. This investigation was made on the hypothesis that study of the nitrogen and phosphorus nutrient systems within the caves might offer a bridge between the iodine chemistry and the marine bacteria which are assumed to be the agent of change of the iodine in the caves. Accordingly, the hydrography, the nutrient chemistry, and some further iodine studies were made of two anchialine caves on the east coast of the Adriatic Sea in Croatia. Iodate and iodide were determined by differential pulse voltammetry and cathodic stripping square-wave voltammetry, respectively. Total iodine was determined indirectly, as iodate, after oxidation of reduced iodine species with UV irradiation and strong chemical oxidants. Nutrient concentrations were measured by spectrophotometry. Nutrient profiles within the well stratified water columns indicate a relatively short-lived surface source of nitrate and phosphate to the caves, with a more conventional, mid-water, nutrient regeneration system. The latter involves nitrite and ammonium at the bottom of the halocline, suggestive of both autotrophic and heterotrophic microbial activity. High iodate/low iodide deep water, and conservative behaviour of total inorganic iodine were confirmed in both systems. Iodate is reduced to iodide in the hypoxic region where nutrient regeneration occurs. The concentrations of organic iodine were surprisingly high in both systems, generally increasing toward the surface, where it comprised almost 80% of total iodine. As with alkalinity and silica, the results suggest that this refractive iodine component is liberated during dissolution of the surrounding karst rock. A major, natural flushing of one of the caves with fresh water was confirmed, showing that the cave systems offer the opportunity to re-start investigations periodically.


Anchialine systems Redox speciation Inorganic iodine Organic iodine Nutrients 



The financial support of the National Park “Mljet” research project and the Ministry of Science, Education and Sports of the Republic of Croatia, under Project 098-0982934-2720, “Interactions of trace metals in aquatic environment”, is gratefully acknowledged. We thank the Croatian Meteorological and Hydrological Service for precipitation data. We wish to thank the members of the Croatian Biospeleological Society Helena Bilandžija, Vedran Jalžić, and Ana Komarički, with special thanks to speleo diver Branko Jalžić for the underwater sampling. Željko Kwokal is thanked for assistance with sampling. We thank two anonymous referees, guest editors Professor Carol Wicks and Professor William F. Humphreys, and the Editor in Chief, Professor Koen Martens, for their valuable comments and suggestions.


  1. Amachi, S., Y. Muramatsu, Y. Akiyama, K. Miyazaki, S. Yoshiki, S. Hanada, Y. Kamagata, T. Ban-nai, H. Shinoyama & T. Fujii, 2005. Isolation of iodide-oxidizing bacteria from iodide-rich natural gas brines and seawaters. Microbial Ecology 49: 547–557.PubMedCrossRefGoogle Scholar
  2. Andersen, S., S. B. Petersen & P. Laurberg, 2002. Iodine in drinking water in Denmark is bound in humic substances. European Journal of Endocrinology 147: 663–670.PubMedCrossRefGoogle Scholar
  3. Anschutz, P., B. Sundby, L. Lefrancois, G. W. Luther III & A. Mucci, 2000. Interactions between metal oxides and species of nitrogen and iodine in bioturbated marine sediments. Geochimica et Cosmochimica Acta 64: 2751–2763.CrossRefGoogle Scholar
  4. Beck, N. G. & K. W. Bruland, 2000. Diel biogeochemical cycling in a hyperventilating shallow estuarine environment. Estuaries 23: 177–187.CrossRefGoogle Scholar
  5. Benović, A., D. Lučić, V. Onofri, M. Peharda, M. Carić, N. Jasprica & S. Bobanović-Ćolić, 2000. Ecological characteristics of the Mljet Island seawater lakes (South Adriatic Sea) with special reference to their resident populations of medusae. Scientia Marina 64: 197–206.CrossRefGoogle Scholar
  6. Bluhm, K., P. Croot, K. Wuttig & K. Lochte, 2010. Transformation of iodate to iodide in marine phytoplankton driven by cell senescence. Aquatic Biology 11: 1–15.CrossRefGoogle Scholar
  7. Bower, C. E. & T. Holm-Hansen, 1980. A salicylate-hypochlorite method for determining ammonia in seawater. Canadian Journal of Fisheries and Aquatic Sciences 37: 794–798.CrossRefGoogle Scholar
  8. Brandao, A. C. M., A. D. R. Wagener & K. Wagener, 1994. Model experiments on the diurnal cycling of iodine in seawater. Marine Chemistry 46: 25–31.CrossRefGoogle Scholar
  9. Butler, E. C. V. & J. D. Smith, 1980. Iodine speciation in seawater – the analytical use of ultra-violet photo-oxidation and differential pulse polarography. Deep-Sea Research 27: 489–493.CrossRefGoogle Scholar
  10. Butler, E. C. V., J. D. Smith & N. S. Fisher, 1981. Influence of phytoplankton on iodine speciation in seawater. Limnology and Oceanography 26: 382–386.CrossRefGoogle Scholar
  11. Campos, M. L. A. M., A. M. Farrenkopf, T. D. Jickells & G. W. Luther III, 1996. A comparison of dissolved iodine cycling at the Bermuda Atlantic time-series station and Hawaii ocean time series station. Deep-Sea Research Part II 43: 455–466.CrossRefGoogle Scholar
  12. Chance, R., G. Malin, T. Jickells & A. R. Baker, 2007. Reduction of iodate to iodide by cold water diatom cultures. Marine Chemistry 105: 169–180.CrossRefGoogle Scholar
  13. Chance, R., K. Weston, A. R. Baker, C. Hughes, G. Malin, L. Carpenter, M. P. Meredith, A. Clarke, T. D. Jickells, P. Mann & H. Rossetti, 2010. Seasonal and interannual variation of dissolved iodine speciation at a coastal Antarctic site. Marine Chemistry 118: 171–181.CrossRefGoogle Scholar
  14. Cook, P. L. M., P. D. Carpenter & E. C. V. Butler, 2000. Speciation of dissolved iodine in the waters of a humic-rich estuary. Marine Chemistry 69: 179–192.CrossRefGoogle Scholar
  15. Cuculić, V., N. Cukrov, Ž. Kwokal & C. Garnier, 2010. Trace metals and dissolved organic carbon in water column of an anchialine object in Mljet National Park – Croatia. 39th CIESM Proceedings, Venice, Italy, Rapp. Comm. int. Mer Médit, Vol. 39: 236.Google Scholar
  16. Edmunds, W. M. & P. L. Smedley, 1996. Groundwater geochemistry and health: an overview. In Appleton, J. D., R. Fuge & G. J. H. McCall (eds), Environmental Geochemistry and Health, Vol. 113. Geological Society, London, special publication: 91–105.Google Scholar
  17. Edwards, A. & V. W. Truesdale, 1997. Regeneration of inorganic iodine species in Loch Etive, a natural leaky incubator. Estuarine, Coastal and Shelf Science 45: 357–366.CrossRefGoogle Scholar
  18. Elderfield, H. & V. W. Truesdale, 1980. On the biophilic nature of iodine in seawater. Earth and Planetary Science Letters 50: 105–114.CrossRefGoogle Scholar
  19. Farrenkopf, A. M., M. E. Dollhopf, S. M. Ni Chadain, G. W. Luther III & K. H. Nealson, 1997a. Reduction of iodate in seawater during Arabian Sea shipboard incubations and in laboratory cultures of the marine bacterium Shewanella putrefaciens strain MR-4. Marine Chemistry 57: 347–354.CrossRefGoogle Scholar
  20. Farrenkopf, A. M., G. W. Luther III, V. W. Truesdale & C. H. Van der Weijden, 1997b. Sub-surface iodide maxima: evidence for biologically catalyzed redox cycling in Arabian Sea OMZ during the SW intermonsoon. Deep-Sea Research 44: 1391–1409.CrossRefGoogle Scholar
  21. Fox, P. M., D. B. Kent & J. A. Davis, 2010. Redox transformations and transport of cesium and iodine (−1, 0, +5) in oxidizing and reducing zones of a sand and gravel aquifer. Environmental Science and Technology 44: 1940–1946.PubMedCrossRefGoogle Scholar
  22. Fuse, H., H. Inoue, K. Murakami, O. Takimura & Y. Yamaoka, 2003. Production of free and organic iodine by Roseovarius spp. FEMS Microbiology Letters 229: 189–194.PubMedCrossRefGoogle Scholar
  23. Gallard, H., S. Allard, R. Nicolau, U. von Gunten & J. P. Croué, 2009. Formation of iodinated organic compounds by oxidation of iodide-containing waters with manganese dioxide. Environmental Science and Technology 43: 7003–7009.PubMedCrossRefGoogle Scholar
  24. Gilfedder, B. S., M. Petri & H. Biester, 2008. Iodine speciation and cycling in limnic systems: observations from a humic rich headwater lake (Mummelsee). Biogeosciences Discussions 5: 25–64.CrossRefGoogle Scholar
  25. Govorčin, D. P., M. Juračić, N. Horvatinčić & V. Onofri, 2001. Holocene sedimentation in the Soline Channel (Mljet Lakes, Adriatic Sea). Natura Croatica 10: 247–258.Google Scholar
  26. Gozlan, R. S., 1968. Isolation of iodine-producing bacteria from aquaria. Antonie van Leeuwenhoek 34: 226.PubMedCrossRefGoogle Scholar
  27. Gozlan, R. S. & P. Margalith, 1974. Iodide oxidation by Pseudomonas iodooxidans. Journal of Applied Bacteriology 37: 493–499.PubMedCrossRefGoogle Scholar
  28. Guillard, R. R. L. & J. H. Ryther, 1962. Studies of marine planktonic diatoms: I. Cyclotella nana Hustedt, and Detonula Confervacea (Cleve) Gran. Canadian Journal of Microbiology 8: 229–239.PubMedCrossRefGoogle Scholar
  29. Herring, J. R. & P. S. Liss, 1974. A new method for the determination of iodine species in seawater. Deep-Sea Research 21: 777–783.Google Scholar
  30. Hopkinson, C. S. & J. J. Vallino, 2005. Efficient export of carbon to the deep ocean through dissolved organic matter. Nature 433: 142–145.PubMedCrossRefGoogle Scholar
  31. Hou, X., A. Aldahan, S. P. Nielsen, G. Possnert, H. Nies & J. Hedfors, 2007. Speciation of 129I and 127I in seawater and implications for sources and transport pathways in the North Sea. Environmental Science and Technology 41: 5993–5999.PubMedCrossRefGoogle Scholar
  32. Hu, Q., P. Zhao, J. E. Moran & J. C. Seaman, 2005. Sorption and transport of iodine species in sediments from the Savannah River and Hanford Sites. Journal of Contaminant Hydrology 78: 185–205.PubMedCrossRefGoogle Scholar
  33. Humphreys, W. F., 1999. Physico-chemical profile and energy fixation in Bundera Sinkhole, an anchialine remiped habitat in north-western Australia. Journal of the Royal Society of Western Australia 82: 89–98.Google Scholar
  34. Humphreys, W. F., 2009. Hydrogeology and groundwater ecology: does each inform the other? Hydrogeology Journal 17: 5–21.CrossRefGoogle Scholar
  35. Humphreys, W. F., A. Poole, S. M. Eberhard & D. Warren, 1999. Effects of research diving on the physico-chemical profile of Bundera Sinkhole, an anchialine remiped habitat at Cape Range, Western Australia. Journal of the Royal Society of Western Australia 82: 99–108.Google Scholar
  36. Humphreys, W. F., C. H. S. Watts, S. J. B. Cooper & R. Leijs, 2009. Groundwater estuaries of salt lakes: buried pools of endemic biodiversity on the western plateau, Australia. Hydrobiologia 626: 79–95.CrossRefGoogle Scholar
  37. Iliffe, T. M., C. W. Hart Jr. & R. B. Manning, 1983. Biogeography and the caves of Bermuda. Nature 302: 141–142.CrossRefGoogle Scholar
  38. Iliffe, T. M., T. D. Jickells & M. S. Brewer, 1984. Organic pollution of an inland marine cave from Bermuda. Marine Environmental Research 12: 173–189.CrossRefGoogle Scholar
  39. Jones, S. D. & V. W. Truesdale, 1984. Dissolved iodine species in a British freshwater system. Limnology and Oceanography 29: 1016–1024.CrossRefGoogle Scholar
  40. Lu, Z., H. C. Jenkyns & R. E. M. Rickaby, 2010. Iodine to calcium ratios in marine carbonate as a paleo-redox proxy during oceanic anoxic events. Geology 38: 1107–1110.CrossRefGoogle Scholar
  41. Luther, G. W. III., 1991. Sulfur and iodine speciation in the water column of the Black Sea. In Izdar, E. & J. W. Murray (eds), Black Sea Oceanography. Kluwer Academic Publishers, The Netherlands: 187–204.Google Scholar
  42. Luther, G. W. III. & T. Campbell, 1991. Iodine speciation in the water column of the Black Sea. Deep-Sea Research 38: S875–S882.CrossRefGoogle Scholar
  43. Luther, G. W. III., C. B. Swartz & W. J. Ullman, 1988. Direct determination of iodide in seawater by cathodic stripping square wave voltammetry. Analytical Chemistry 60: 1721–1724.CrossRefGoogle Scholar
  44. Luther, G. W. III., T. Ferdleman, C. H. Culberson, J. Kostka & J. Wu, 1991. Iodine chemistry in the water column of the Chesapeake Bay: evidence for organic iodine forms. Estuarine, Coastal and Shelf Science 32: 267–279.CrossRefGoogle Scholar
  45. Luther, G. W. III., J. Wu & J. B. Cullen, 1995. Redox chemistry of iodine in seawater revisited: frontier molecular orbital theory considerations. Advances in Chemistry Series 244: 135–155.Google Scholar
  46. Miko, S., J. Halamić, Z. Peh & L. Galović, 2001. Geochemical baseline mapping of soils developed on diverse bedrock from two regions in Croatia. Geologia Croatica 54: 53–118.Google Scholar
  47. Moisan, T. A., W. M. Dunstan, A. Udomkit & G. T. F. Wong, 1994. The uptake of iodate by marine phytoplankton. Journal of Phycology 30: 580–587.CrossRefGoogle Scholar
  48. Moore, W. S., 1999. The subterranean estuary: a reaction zone of ground water and sea water. Marine Chemistry 65: 111–125.CrossRefGoogle Scholar
  49. Neal, C., M. Neal, H. Wickham, L. Hill & S. Harman, 2007. Dissolved iodine in rainfall, cloud, stream and groundwater in the Plynlimon area of mid-Wales. Hydrology and Earth System Sciences 11: 283–293.CrossRefGoogle Scholar
  50. Omanović, D., 2006. ECDSOFT – ElectroChemistry Data SOFTware [available on internet at].
  51. Omanović, D. & M. Branica, 1998. Automation of voltammetric measurements by polarographic analyser PAR 384B. Croatica Chemica Acta 71: 421–433.Google Scholar
  52. Pižeta, I., D. Omanović & M. Branica, 1999. The influence of data treatment on the interpretation of experimental results in voltammetry. Analytica Chimica Acta 401: 163–172.CrossRefGoogle Scholar
  53. Pohlman, J. W., T. M. Iliffe & L. A. Cifuentes, 1997. A stable isotope study of organic cycling and the ecology of an anchialine cave ecosystem. Marine Ecology Progress Series 155: 17–27.CrossRefGoogle Scholar
  54. Rädlinger, G. & K. G. Heumann, 2000. Transformation of iodide in natural and wastewater systems by fixation on humic substances. Environmental Science and Technology 34: 3932–3936.CrossRefGoogle Scholar
  55. Rakestraw, N. W., 1936. The occurrence and significance of nitrite in the sea. The Biological Bulletin 71: 133–167.CrossRefGoogle Scholar
  56. Schlegel, M. L., P. Reiller, F. Mercier-Bion, N. Barré & V. Moulin, 2006. Molecular environment of iodine in naturally iodinated humic substances: insight from X-ray absorption spectroscopy. Geochimica et Cosmochimica Acta 70: 5536–5551.CrossRefGoogle Scholar
  57. Schwehr, K. A. & P. H. Santschi, 2003. Sensitive determination of iodine species, including organo-iodine, for freshwater and seawater samples using high performance liquid chromatography and spectrophotometric detection. Analytica Chimica Acta 182: 59–71.CrossRefGoogle Scholar
  58. Schwehr, K. A., P. H. Santschi & D. Elmore, 2005. The dissolved organic iodine species of the isotopic ratio of 129I/127I: a novel tool for tracing terrestrial organic carbon in the estuarine surface waters of Galveston Bay, Texas. Limnology and Oceanography: Methods 3: 326–337.CrossRefGoogle Scholar
  59. Seymour, J. R., W. F. Humphreys & J. G. Mitchell, 2007. Stratification of the microbial community inhabiting an anchialine sinkhole. Aquatic Microbial Ecology 50: 11–24.CrossRefGoogle Scholar
  60. Shahack-Gross, R., F. Berna, P. Karkanas & S. Weiner, 2004. Bat guano and preservation of archaeological remains in cave sites. Journal of Archaeological Science 31: 1259–1272.CrossRefGoogle Scholar
  61. Sillen, L. G., 1961. The physical chemistry of sea water. In Sears, M. (ed.), Chemical Oceanography. American Association for the Advancement of Science, Washington, DC: 549–582.Google Scholar
  62. Sket, B., 1996. The ecology of anchialine caves. Trends in Ecology & Evolution 11: 221–225.CrossRefGoogle Scholar
  63. Slomp, C. P. & P. Van Cappellen, 2004. Nutrient inputs to the coastal ocean through submarine groundwater discharge: controls and potential impact. Journal of Hydrology 295: 64–86.CrossRefGoogle Scholar
  64. Spokes, L. J. & P. S. Liss, 1996. Photochemically induced redox reactions in seawater: II. Nitrogen and iodine. Marine Chemistry 54: 1–10.CrossRefGoogle Scholar
  65. Sridhar, K. R., K. M. Ashwini, S. Seena & K. S. Sreepada, 2006. Manure qualities of guano of insectivorous cave bat Hipposideros speoris. Tropical and Subtropical Agroecosystems 6: 103–110.Google Scholar
  66. Steinberg, S. M., G. M. Kimble, G. T. Schmett, D. W. Emerson, M. F. Turner & M. Rudin, 2008. Abiotic reaction of iodate with sphagnum peat and other natural organic matter. Journal of Radioanalytical and Nuclear Chemistry 277: 185–191.CrossRefGoogle Scholar
  67. Stipaničev, V. & M. Branica, 1996. Iodine speciation in the water column or the Rogoznica Lake (Eastern Adriatic Coast). Science of the Total Environment 182: 1–9.CrossRefGoogle Scholar
  68. Stock, J. H., T. M. Iliffe & D. Williams, 1986. The concept “anchialine” reconsidered. Stygologia 2: 9092.Google Scholar
  69. Strickland, J. D. H. & T. R. Parsons, 1968. A Practical Handbook of Sea Water Analyses. Fisheries Research Board of Canada, Bulletin 167, Ottawa.Google Scholar
  70. Sugawara, K. & K. Terada, 1967. Iodine assimilation by a marine Navicula sp. and the production of iodate accompanied by growth of the algae. Information Bulletin on Planktology in Japan 14: 213–218.Google Scholar
  71. Terzić, J., Z. Peh & T. Marković, 2010. Hydrochemical properties of transition zone between fresh groundwater and seawater in karst environment of the Adriatic islands, Croatia. Environmental Earth Sciences 59: 1629–1642.CrossRefGoogle Scholar
  72. Tian, R. C. & E. Nicolas, 1995. Iodine speciation in the northwestern Mediterranean Sea, method and vertical profile. Marine Chemistry 48: 151–156.CrossRefGoogle Scholar
  73. Tian, R. C., J. C. Marty, E. Nicolas, J. Chiavérini, D. Ruiz-Ping & M. D. Pizay, 1996. Iodine speciation: a potential indicator to evaluate new production versus regenerated production. Deep-Sea Research I 43: 723–738.CrossRefGoogle Scholar
  74. Truesdale, V. W., 1974. The chemical reduction of molecular iodine in seawater. Deep Sea Research and Oceanographic Abstracts 21: 761–766.CrossRefGoogle Scholar
  75. Truesdale, V. W., 1975. ‘Reactive’ and ‘unreactive’ iodine in seawater – a possible indication of an organically bound iodine fraction. Marine Chemistry 3: 111–119.CrossRefGoogle Scholar
  76. Truesdale, V. W., 1978. Iodine in inshore and offshore waters. Marine Chemistry 6: 1–13.CrossRefGoogle Scholar
  77. Truesdale, V. W., 1994a. A re-assessment of Redfield correlations between dissolved iodine and nutrients in oceanic waters, and a strategy for further investigations of iodine. Marine Chemistry 48: 43–56.CrossRefGoogle Scholar
  78. Truesdale, V. W., 1994b. Distribution of dissolved iodine in the Irish Sea, a temperate shelf sea. Estuarine, Coastal and Shelf Science 38: 435–446.CrossRefGoogle Scholar
  79. Truesdale, V. W., 2007. On the feasibility of some photochemical reactions of iodine in seawater. Marine Chemistry 104: 266–281.CrossRefGoogle Scholar
  80. Truesdale, V. W. & G. W. Bailey, 2002. Iodine in the Southern Benguela system during an upwelling episode. Continental Shelf Research 22: 39–49.CrossRefGoogle Scholar
  81. Truesdale, V. W. & K. Jones, 2000. Steady-state mixing of iodine in shelf seas off the British Isles. Continental Shelf Research 20: 1889–1905.CrossRefGoogle Scholar
  82. Truesdale, V. W. & G. W. Luther III, 1995. Molecular iodine reduction by natural and model organic substances in seawater. Aquatic Geochemistry 1: 89–104.CrossRefGoogle Scholar
  83. Truesdale, V. W. & R. Upstill-Goddard, 2003. Dissolved iodate and total iodine along the British east coast. Estuarine, Coastal and Shelf Science 56: 261–270.CrossRefGoogle Scholar
  84. Truesdale, V. W., A. J. Bale & M. Woodward, 2000. The meridional distribution of dissolved iodine in near-surface waters of the Atlantic Ocean. Progress in Oceanography 45: 387–400.CrossRefGoogle Scholar
  85. Truesdale, V. W., S. F. Watts & A. R. Rendell, 2001. On the possibility of iodide oxidation in the near-surface of the Black Sea and its implications to iodine in the general ocean. Deep Sea Research I 48: 2397–2412.CrossRefGoogle Scholar
  86. Truesdale, V. W., H. Kennedy, S. Agustí & T. J. Waite, 2003. On the relative constancy of iodate and total iodine concentrations accompanying phytoplankton blooms initiated in mesocosm experiments in Antarctica. Limnology and Oceanography 48: 1569–1574.CrossRefGoogle Scholar
  87. Tsunogai, S. & T. Henmi, 1971. Iodine in the surface water of the ocean. Journal of the Oceanographic Society of Japan 27: 67–72.CrossRefGoogle Scholar
  88. Tsunogai, S. & T. Sase, 1969. Formation of iodide iodine in the ocean. Deep-Sea Research 16: 489–496.Google Scholar
  89. Waite, T. J. & V. W. Truesdale, 2003. Iodate reduction by Isochrysis galbana is relatively insensitive to de-activation of nitrate reductase activity – are phytoplankton really responsible for iodate reduction in seawater? Marine Chemistry 81: 137–148.CrossRefGoogle Scholar
  90. Ward, B. B., 2008. Nitrification. In Capone, D. G., D. A. Bronk, M. R. Mulholland & E. J. Carpenter (eds), Nitrogen in the Marine Environment. Elsevier, Amsterdam: 199–262.CrossRefGoogle Scholar
  91. Wong, G. T. F., 1991. The marine geochemistry of iodine. Reviews in Aquatic Sciences 4: 45–73.Google Scholar
  92. Wong, G. T. F., 2001. Coupling iodine speciation to primary, regenerated or “new” production: a re-evaluation. Deep-Sea Research I 48: 1459–1476.CrossRefGoogle Scholar
  93. Wong, G. T. F. & X.-H. Cheng, 1998. Dissolved organic iodine in marine waters: determination, occurrence and analytical implications. Marine Chemistry 59: 271–281.CrossRefGoogle Scholar
  94. Wong, G. T. F. & X.-H. Cheng, 2001. Dissolved organic iodine in marine waters: role in estuarine geochemistry of iodine. Journal of Environmental Monitoring 3: 257–263.PubMedCrossRefGoogle Scholar
  95. Wong, G. T. F. & L.-S. Zhang, 1992a. Changes in the iodine speciation across coastal hydrographic fronts in southeastern United States continental shelf waters. Continental Shelf Research 12: 717–733.CrossRefGoogle Scholar
  96. Wong, G. T. F. & L.-S. Zhang, 1992b. Chemical removal of oxygen with sulfite for the polarographic or voltammetric determination of iodate of iodide in seawater. Marine Chemistry 38: 109–116.CrossRefGoogle Scholar
  97. Wong, G. T. F. & L.-S. Zhang, 2003. Seasonal variations in the speciation of dissolved iodine in the Chesapeake Bay. Estuarine, Coastal and Shelf Science 56: 1093–1106.CrossRefGoogle Scholar
  98. Wong, G. T. F., P. G. Brewer & D. W. Spencer, 1976. The distribution of particulate iodine in the Atlantic Ocean. Earth and Planetary Science Letters 32: 441–450.CrossRefGoogle Scholar
  99. Wong, G. T. F., K. Takayanagi & J. F. Todd, 1985. Dissolved iodine in waters overlying the Orca basin, Gulf of Mexico. Marine Chemistry 17: 177–183.CrossRefGoogle Scholar
  100. Wong, G. T. F., A. U. Piumsomboon & W. M. Dunstan, 2002. The transformation of iodate to iodide in marine phytoplankton cultures. Marine Ecology Progress Series 237: 27–39.CrossRefGoogle Scholar
  101. Zhang, J.-Z. & C. J. Fischer, 2006. A simplified resorcinol method for direct spectrophotometric determination of nitrate in seawater. Marine Chemistry 99: 220–226.CrossRefGoogle Scholar
  102. Zhang, J.-Z. & M. Whitfield, 1986. Kinetics of inorganic redox reactions in seawater. I. The reduction of iodate by bisulphide. Marine Chemistry 19: 121–137.CrossRefGoogle Scholar
  103. Žic, V. & M. Branica, 2006. The distributions of iodate and iodide in Rogoznica Lake (East Adriatic Coast). Estuarine, Coastal and Shelf Science 66: 55–66.CrossRefGoogle Scholar
  104. Žic, V., V. W. Truesdale & N. Cukrov, 2008. The distribution of iodide and iodate in anchialine cave waters – evidence for sustained localised oxidation of iodide to iodate in marine water. Marine Chemistry 112: 168–178.CrossRefGoogle Scholar
  105. Žic, V., M. Carić, E. Viollier & I. Ciglenečki, 2010. Intensive sampling of iodine and nutrient speciation in naturally eutrophicated anchialine pond (Rogoznica Lake) during spring and summer seasons. Estuarine, Coastal and Shelf Science 87: 265–274.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Vesna Žic
    • 1
    • 2
    Email author
  • Victor W. Truesdale
    • 3
  • Vlado Cuculić
    • 1
  • Neven Cukrov
    • 1
  1. 1.Division for Marine and Environmental ResearchRuđer Bošković InstituteZagrebCroatia
  2. 2.Central Water Management LaboratoryHrvatske vodeŠibenikCroatia
  3. 3.School of Life SciencesOxford Brookes UniversityOxfordUK

Personalised recommendations