Strong seasonality in the cadmium and phosphate cycling at the subtropical convergence, south-eastern New Zealand
R. D. Frew A E , T. Adu A , M. Gault-Ringold A , A. Hamidian A B , K. I. Currie C , E. Armstrong A and K. A. Hunter D
+ Author Affiliations
- Author Affiliations
A Department of Chemistry, University of Otago, PO Box 56, Union Street, Dunedin, 9056, New Zealand.
B Department of Environment, Faculty of Natural Resources, University of Tehran, 16 Azar Street, Karaj, 31587-77878, Iran.
C National Institute for Water and Atmospheric Research (NIWA), Union Street, Dunedin, 9056, New Zealand.
D Deceased. Formerly at Department of Chemistry, University of Otago, Dunedin, 9056, New Zealand.
E Corresponding author. Email: rfrew@chemistry.otago.ac.nz
Marine and Freshwater Research 71(3) 345-354 https://doi.org/10.1071/MF19216
Submitted: 17 June 2019 Accepted: 13 August 2019 Published: 8 November 2019
Abstract
The global distribution of dissolved cadmium (Cd) in the world’s oceans is generally well understood. However, information on seasonal variability of this and other trace metals in the open ocean is difficult to obtain and, therefore, our understanding is limited. Here, we present a 3-year time series of field measurements of dissolved and particulate Cd and phosphate (PO4) from a transect across the subtropical convergence, south-eastern New Zealand. In the final year of study, the bioactive trace metals (iron, Fe; zinc, Zn; cobalt, Co) and nutrients (nitrate, NO3; silicate, Si(OH)4) were also measured to identify their influence on Cd cycling in the region. Cadmium varied seasonally from 0.009 to 0.137 nM in the sub-Antarctic surface waters (SASW). Zinc in SASW varied between 0.03 and 0.011 nM, which is low enough to suggest Zn limitation year-round. The seasonal input of dissolved Fe may stimulate phytoplankton growth in summer where microplankton (especially diatoms) dominate the phytoplankton distribution. The Cd : PO4 ratio also varied strongly with season (0.015 × 10–3 to 0.05 × 10–3). This seasonal variation in the Cd : PO4 ratio is productivity driven as revealed in the characteristic trend in the Cd : PO4 ratio, particulate Cd and chlorophyll-a measurements. The high seasonal variability between Cd and PO4 complicates the application of the Cd proxy for the reconstruction of historical PO4 concentrations in SASW.
References
Abouchami, W., Galer, S. J. G., de Baar, H. J. W., Middag, R., Vance, D., Zhao, Y., Klunder, M., Mezger, K., Feldmann, H., and Andreae, M. O. (2014). Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian. Geochimica et Cosmochimica Acta 127, 348–367.| Biogeochemical cycling of cadmium isotopes in the Southern Ocean along the Zero Meridian.Crossref | GoogleScholarGoogle Scholar |
Allen, J. T., Brown, L., Sanders, R., Moore, C. M., Mustard, A., Fielding, S., Lucas, M., Rixen, M., Savidge, G., Henson, S., and Mayor, D. (2005). Diatom carbon export enhanced by silicate upwelling in the northeast Atlantic. Nature 437, 728–732.
| Diatom carbon export enhanced by silicate upwelling in the northeast Atlantic.Crossref | GoogleScholarGoogle Scholar | 16193051PubMed |
Baars, O., Abouchami, W., Galer, S. J. G., Boye, M., and Croot, P. L. (2014). Dissolved cadmium in the Southern Ocean: distribution, speciation, and relation to phosphate. Limnology and Oceanography 59, 385–399.
| Dissolved cadmium in the Southern Ocean: distribution, speciation, and relation to phosphate.Crossref | GoogleScholarGoogle Scholar |
Behrenfeld, M. J., and Kolber, Z. S. (1999). Widespread iron limitation of phytoplankton in the South Pacific Ocean. Science 283, 840–843.
| Widespread iron limitation of phytoplankton in the South Pacific Ocean.Crossref | GoogleScholarGoogle Scholar | 9933166PubMed |
Boyd, P., LaRoche, J., Gall, M., Frew, R., and McKay, R. M. L. (1999). Role of iron, light, and silicate in controlling algal biomass in subantarctic waters SE of New Zealand. Journal of Geophysical Research. Oceans 104, 13395–13408.
| Role of iron, light, and silicate in controlling algal biomass in subantarctic waters SE of New Zealand.Crossref | GoogleScholarGoogle Scholar |
Boyd, P. W., Watson, A. J., Law, C. S., Abraham, E. R., Trull, T., Murdoch, R., Bakker, D. C. E., Bowie, A. R., Buesseler, K. O., Chang, H., Charette, M., Croot, P., Downing, K., Frew, R., Gall, M., Hadfield, M., Hall, J., Harvey, M., Jameson, G., LaRoche, J., Liddicoat, M., Ling, R., Maldonado, M. T., McKay, R. M., Nodder, S., Pickmere, S., Pridmore, R., Rintoul, S., Safi, K., Sutton, P., Strzepek, R., Tanneberger, K., Turner, S., Waite, A., and Zeldis, J. (2000). A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization. Nature 407, 695–702.
| A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization.Crossref | GoogleScholarGoogle Scholar | 11048709PubMed |
Boyle, E. A. (1988). Cadmium: chemical tracer of deepwater paleoceanography. Paleoceanography 3, 471–489.
| Cadmium: chemical tracer of deepwater paleoceanography.Crossref | GoogleScholarGoogle Scholar |
Boyle, E. A., Sclater, F., and Edmond, J. M. (1976). On the marine geochemistry of cadmium. Nature 263, 42–44.
| On the marine geochemistry of cadmium.Crossref | GoogleScholarGoogle Scholar |
Bruland, K. W. (1989). Complexation of zinc by natural organic-ligands in the central North Pacific. Limnology and Oceanography 34, 269–285.
| Complexation of zinc by natural organic-ligands in the central North Pacific.Crossref | GoogleScholarGoogle Scholar |
Bruland, K. W., Franks, R. P., Knauer, G. A., and Martin, J. H. (1979). Sampling and analytical methods for the determination of copper, cadmium, zinc, and nickel at the nanogram per liter level in sea water. Analytica Chimica Acta 105, 233–245.
| Sampling and analytical methods for the determination of copper, cadmium, zinc, and nickel at the nanogram per liter level in sea water.Crossref | GoogleScholarGoogle Scholar |
Crawford, D. W., Lipsen, M. S., Purdie, D. A., Lohan, M. C., Statham, P. J., Whitney, F. A., Putland, J. N., Johnson, W. K., Sutherland, N., Peterson, T. D., Harrison, P. J., and Wong, C. S. (2003). Influence of zinc and iron enrichments on phytoplankton growth in the northeastern subarctic Pacific. Limnology and Oceanography 48, 1583–1600.
| Influence of zinc and iron enrichments on phytoplankton growth in the northeastern subarctic Pacific.Crossref | GoogleScholarGoogle Scholar |
Croot, P. L., and Hunter, K. A. (1998). Trace metal distributions across the continental shelf near Otago Peninsula, New Zealand. Marine Chemistry 62, 185–201.
| Trace metal distributions across the continental shelf near Otago Peninsula, New Zealand.Crossref | GoogleScholarGoogle Scholar |
Croot, P. L., Frew, R. D., Sander, S., Hunter, K. A., Ellwood, M. J., Pickmere, S. E., Abraham, E. R., Law, C. S., Smith, M. J., and Boyd, P. W. (2007). Physical mixing effects on iron biogeochemical cycling: FeCycle experiment. Journal of Geophysical Research – Oceans 112, C06015.
Cullen, J. T. (2006). On the nonlinear relationship between dissolved cadmium and phosphate in the modern global ocean: could chronic iron limitation of phytoplankton growth cause the kink? Limnology and Oceanography 51, 1369–1380.
| On the nonlinear relationship between dissolved cadmium and phosphate in the modern global ocean: could chronic iron limitation of phytoplankton growth cause the kink?Crossref | GoogleScholarGoogle Scholar |
Cullen, J. T., Lane, T. W., Morel, F. M. M., and Sherrell, R. M. (1999a). Modulation of cadmium uptake in phytoplankton by seawater CO2 concentration. Nature 402, 165–167.
| Modulation of cadmium uptake in phytoplankton by seawater CO2 concentration.Crossref | GoogleScholarGoogle Scholar |
Cullen, J. T., Lane, T. W., Morel, F. M. M., and Sherrell, R. M. (1999b). Modulation of cadmium uptake in phytoplankton by seawater CO2 concentration. Nature 402, 165–167.
| Modulation of cadmium uptake in phytoplankton by seawater CO2 concentration.Crossref | GoogleScholarGoogle Scholar |
Cullen, J. T., Chase, Z., Coale, K. H., Fitzwater, S. E., and Sherrell, R. M. (2003). Effect of iron limitation on the cadmium to phosphorus ratio of natural phytoplankton assemblages from the Southern Ocean. Limnology and Oceanography 48, 1079–1087.
| Effect of iron limitation on the cadmium to phosphorus ratio of natural phytoplankton assemblages from the Southern Ocean.Crossref | GoogleScholarGoogle Scholar |
Daly, K. L., Smith, W. O., Johnson, G. C., DiTullio, G. R., Jones, D. R., Mordy, C. W., Feely, R. A., Hansell, D. A., and Zhang, J. Z. (2001). Hydrography, nutrients, and carbon pools in the Pacific sector of the Southern Ocean: implications for carbon flux. Journal of Geophysical Research. Oceans 106, 7107–7124.
| Hydrography, nutrients, and carbon pools in the Pacific sector of the Southern Ocean: implications for carbon flux.Crossref | GoogleScholarGoogle Scholar |
Danilovtseva, E., Aseyev, V., Karesoja, M., and Annenkov, V. (2009). Sorption of silicic acid from non-saturated aqueous solution by a complex of zinc ions with poly(vinylamine). European Polymer Journal 45, 1391–1396.
| Sorption of silicic acid from non-saturated aqueous solution by a complex of zinc ions with poly(vinylamine).Crossref | GoogleScholarGoogle Scholar |
de Baar, H. J. W., Saager, P. M., Nolting, R. F., and van der Meer, J. (1994). Cadmium versus phosphate in the world ocean. Marine Chemistry 46, 261–281.
| Cadmium versus phosphate in the world ocean.Crossref | GoogleScholarGoogle Scholar |
de Souza, G. F., Khatiwala, S. P., Hain, M. P., Little, S. H., and Vance, D. (2018). On the origin of the marine zinc–silicon correlation. Earth and Planetary Science Letters 492, 22–34.
| On the origin of the marine zinc–silicon correlation.Crossref | GoogleScholarGoogle Scholar |
Dore, J. E., Houlihan, T., Hebel, D. V., Tien, G., Tupas, L., and Karl, D. M. (1996). Freezing as a method of sample preservation for the analysis of dissolved inorganic nutrients in seawater. Marine Chemistry 53, 173–185.
| Freezing as a method of sample preservation for the analysis of dissolved inorganic nutrients in seawater.Crossref | GoogleScholarGoogle Scholar |
Elderfield, H., and Rickaby, R. E. M. (2000). Oceanic Cd/P and nutrient utilisation in the glacial Southern Ocean. Nature 405, 305–310.
| Oceanic Cd/P and nutrient utilisation in the glacial Southern Ocean.Crossref | GoogleScholarGoogle Scholar | 10830952PubMed |
Ellwood, M. J. (2004). Zinc and cadmium speciation in subantarctic waters east of New Zealand. Marine Chemistry 87, 37–58.
| Zinc and cadmium speciation in subantarctic waters east of New Zealand.Crossref | GoogleScholarGoogle Scholar |
Ellwood, M. J. (2008). Wintertime trace metal (Zn, Cu, Ni, Cd, Pb and Co) and nutrient distributions in the Subantarctic Zone between 40–52°S; 155–160°E. Marine Chemistry 112, 107–117.
| Wintertime trace metal (Zn, Cu, Ni, Cd, Pb and Co) and nutrient distributions in the Subantarctic Zone between 40–52°S; 155–160°E.Crossref | GoogleScholarGoogle Scholar |
Ellwood, M., and van den Berg, C. M. G. (2000). Zinc speciation in the northeastern Atlantic Ocean. Marine Chemistry 68, 295–306.
| Zinc speciation in the northeastern Atlantic Ocean.Crossref | GoogleScholarGoogle Scholar |
Frew, R. D. (1995). Antarctic bottom water formation and the global cadmium to phosphorus relationship. Geophysical Research Letters 22, 2349–2352.
| Antarctic bottom water formation and the global cadmium to phosphorus relationship.Crossref | GoogleScholarGoogle Scholar |
Frew, R. D., and Hunter, K. A. (1992). Influence of Southern Ocean waters on the cadmium–phosphate properties of the global ocean. Nature 360, 144–146.
| Influence of Southern Ocean waters on the cadmium–phosphate properties of the global ocean.Crossref | GoogleScholarGoogle Scholar |
Frew, R. D., and Hunter, K. A. (1995). Cadmium–phosphorus cycling at the subtropical convergence south of New Zealand. Marine Chemistry 51, 223–237.
| Cadmium–phosphorus cycling at the subtropical convergence south of New Zealand.Crossref | GoogleScholarGoogle Scholar |
Frew, R. D., Hunter, K. A., and Beyer, R. (1989). Cadmium in the dredge oyster Ostrea lutaria: dependence on age, body-weight and distribution in internal organs. Marine Pollution Bulletin 20, 463–464.
| Cadmium in the dredge oyster Ostrea lutaria: dependence on age, body-weight and distribution in internal organs.Crossref | GoogleScholarGoogle Scholar |
Frew, R. D., Heywood, K. J., and Dennis, P. F. (1995). Oxygen isotope study of water masses in the Princess Elizabeth Trough, Antarctica. Marine Chemistry 49, 141–153.
| Oxygen isotope study of water masses in the Princess Elizabeth Trough, Antarctica.Crossref | GoogleScholarGoogle Scholar |
Frew, R. D., Hunter, K. A., and Beyer, R. (1997). Cadmium in oysters and sediments from Foveaux Strait, New Zealand. In ‘Proceedings of the Trace Element Group of New Zealand’. (Ed. RB Macaskill.) pp. 1–23. (Waikato University Press: Waikato, New Zealand.)
Frew, R., Bowie, A., Croot, P., and Pickmere, S. (2001). Macronutrient and trace-metal geochemistry of an in situ iron-induced Southern Ocean bloom. Deep-sea Research – II. Topical Studies in Oceanography 48, 2467–2481.
| Macronutrient and trace-metal geochemistry of an in situ iron-induced Southern Ocean bloom.Crossref | GoogleScholarGoogle Scholar |
Gault-Ringold, M., Adu, T., Stirling, C. H., Frew, R. D., and Hunter, K. A. (2012). Anomalous biogeochemical behaviour of cadmium in subantarctic surface waters: mechanistic constraints from cadmium isotopes. Earth and Planetary Science Letters 341–344, 94–103.
| Anomalous biogeochemical behaviour of cadmium in subantarctic surface waters: mechanistic constraints from cadmium isotopes.Crossref | GoogleScholarGoogle Scholar |
George, E., Stirling, C. H., Gault-Ringold, M., Ellwood, M. J., and Middag, R. (2019). Marine biogeochemical cycling of cadmium and cadmium isotopes in the extreme nutrient-depleted subtropical gyre of the South West Pacific Ocean. Earth and Planetary Science Letters 514, 84–95.
| Marine biogeochemical cycling of cadmium and cadmium isotopes in the extreme nutrient-depleted subtropical gyre of the South West Pacific Ocean.Crossref | GoogleScholarGoogle Scholar |
Hawke, D. J. (1992). Salinity variability in shelf waters near Otago Peninsula, New Zealand, on a timescale of hours. New Zealand Journal of Marine and Freshwater Research 26, 167–173.
| Salinity variability in shelf waters near Otago Peninsula, New Zealand, on a timescale of hours.Crossref | GoogleScholarGoogle Scholar |
Hawke, D. J. (1995). Reactive silicate in shelf waters near Otago Peninsula, New Zealand. Marine and Freshwater Research 46, 427–433.
| Reactive silicate in shelf waters near Otago Peninsula, New Zealand.Crossref | GoogleScholarGoogle Scholar |
Hawke, D. J., and Hunter, K. A. (1992). Reactive-P distribution near Otago Peninsula, New Zealand: an advection-dominated shelf system containing a headland eddy. Estuarine, Coastal and Shelf Science 34, 141–155.
| Reactive-P distribution near Otago Peninsula, New Zealand: an advection-dominated shelf system containing a headland eddy.Crossref | GoogleScholarGoogle Scholar |
Haywood, G. J. (2004). Some effects of river discharges and currents on phytoplankton in the sea off Otago, New Zealand. New Zealand Journal of Marine and Freshwater Research 38, 103–114.
| Some effects of river discharges and currents on phytoplankton in the sea off Otago, New Zealand.Crossref | GoogleScholarGoogle Scholar |
Heath, R. A. (1972). The Southland Current. New Zealand Journal of Marine and Freshwater Research 6, 497–533.
| The Southland Current.Crossref | GoogleScholarGoogle Scholar |
Heath, R. A. (1985). A review of the physical oceanography of the seas around New Zealand: 1982. New Zealand Journal of Marine and Freshwater Research 19, 79–124.
| A review of the physical oceanography of the seas around New Zealand: 1982.Crossref | GoogleScholarGoogle Scholar |
Hendry, K. R., Rickaby, R. E. M., de Hoog, J. C. M., Weston, K., and Rehkamper, M. (2008). Cadmium and phosphate in coastal Antarctic seawater: implications for Southern Ocean nutrient cycling. Marine Chemistry 112, 149–157.
| Cadmium and phosphate in coastal Antarctic seawater: implications for Southern Ocean nutrient cycling.Crossref | GoogleScholarGoogle Scholar |
Hutchins, D. A., and Bruland, K. W. (1998). Iron-limited diatom growth and Si : N uptake ratios in a coastal upwelling regime. Nature 393, 561–564.
| Iron-limited diatom growth and Si : N uptake ratios in a coastal upwelling regime.Crossref | GoogleScholarGoogle Scholar |
Hutchins, D. A., DiTullio, G. R., Zhang, Y., and Bruland, K. W. (1998). An iron limitation mosaic in the California upwelling regime. Limnology and Oceanography 43, 1037–1054.
| An iron limitation mosaic in the California upwelling regime.Crossref | GoogleScholarGoogle Scholar |
Jones, K. N., Currie, K. I., McGraw, C. M., and Hunter, K. A. (2013). The effect of coastal processes on phytoplankton biomass and primary production within the near-shore Subtropical Frontal Zone. Estuarine, Coastal and Shelf Science 124, 44–55.
| The effect of coastal processes on phytoplankton biomass and primary production within the near-shore Subtropical Frontal Zone.Crossref | GoogleScholarGoogle Scholar |
Lacan, F., Francois, R., Ji, Y. C., and Sherrell, R. M. (2006). Cadmium isotopic composition in the ocean. Geochimica et Cosmochimica Acta 70, 5104–5118.
| Cadmium isotopic composition in the ocean.Crossref | GoogleScholarGoogle Scholar |
Lane, T. W., and Morel, F. M. M. (2000a). A biological function for cadmium in marine diatoms. Proceedings of the National Academy of Sciences of the United States of America 97, 4627–4631.
| A biological function for cadmium in marine diatoms.Crossref | GoogleScholarGoogle Scholar | 10781068PubMed |
Lane, T. W., and Morel, F. M. M. (2000b). Regulation of carbonic anhydrase expression by zinc, cobalt, and carbon dioxide in the marine diatom Thalassiosira weissflogii. Plant Physiology 123, 345–352.
| Regulation of carbonic anhydrase expression by zinc, cobalt, and carbon dioxide in the marine diatom Thalassiosira weissflogii.Crossref | GoogleScholarGoogle Scholar | 10806251PubMed |
Lee, J. G., and Morel, F. M. M. (1995). Replacement of zinc by cadmium in marine phytoplankton. Marine Ecology Progress Series 127, 305–309.
| Replacement of zinc by cadmium in marine phytoplankton.Crossref | GoogleScholarGoogle Scholar |
Lohan, M. C., Statham, P. J., and Crawford, D. W. (2002). Total dissolved zinc in the upper water column of the subarctic North East Pacific. Deep-sea Research – II. Topical Studies in Oceanography 49, 5793–5808.
| Total dissolved zinc in the upper water column of the subarctic North East Pacific.Crossref | GoogleScholarGoogle Scholar |
Löscher, B. M., van der Meer, J., de Baar, H. J. W., Saager, P. M., and de Jong, J. T. M. (1997). The global Cd/phosphate relationship in deep ocean waters and the need for accuracy. Marine Chemistry 59, 87–93.
| The global Cd/phosphate relationship in deep ocean waters and the need for accuracy.Crossref | GoogleScholarGoogle Scholar |
Löscher, B. M., de Jong, J. T. M., and de Baar, H. J. W. (1998). The distribution and preferential uptake of cadmium at 6°W in the Southern Ocean. Marine Chemistry 62, 259–286.
| The distribution and preferential uptake of cadmium at 6°W in the Southern Ocean.Crossref | GoogleScholarGoogle Scholar |
Martin, J. H., Gordon, R. M., and Fitzwater, S. E. (1990). Iron in Antarctic waters. Nature 345, 156–158.
| Iron in Antarctic waters.Crossref | GoogleScholarGoogle Scholar |
Middag, R., van Heuven, S., Bruland, K. W., and de Baar, H. J. W. (2018). The relationship between cadmium and phosphate in the Atlantic Ocean unravelled. Earth and Planetary Science Letters 492, 79–88.
| The relationship between cadmium and phosphate in the Atlantic Ocean unravelled.Crossref | GoogleScholarGoogle Scholar |
Miller, C. B. (2004). ‘Biological Oceanography.’ (Blackwell Science: Oxford, UK.)
Milne, S. B., Tallman, K. A., Serwa, R., Rouzer, C. A., Armstrong, M. D., Marnett, L. J., Lukehart, C. M., Porter, N. A., and Brown, H. A. (2010). Capture and release of alkyne-derivatized glycerophospholipids using cobalt chemistry. Nature Chemical Biology 6, 205–207.
| Capture and release of alkyne-derivatized glycerophospholipids using cobalt chemistry.Crossref | GoogleScholarGoogle Scholar | 20098428PubMed |
Morel, F. M. M. (2008). The co-evolution of phytoplankton and trace element cycles in the oceans. Geobiology 6, 318–324.
| The co-evolution of phytoplankton and trace element cycles in the oceans.Crossref | GoogleScholarGoogle Scholar |
Morel, F. M. M., Reinfelder, J. R., Roberts, S. B., Chamberlain, C. P., Lee, J. G., and Lee, D. (1994). Zinc and carbon co-limitation of marine phytoplankton. Nature 369, 740–742.
| Zinc and carbon co-limitation of marine phytoplankton.Crossref | GoogleScholarGoogle Scholar |
Murphy, J., and Riley, J. P. (1962). A modified single solution method for the determination of phosphate in natural waters. Analytica Chimica Acta 27, 31–36.
| A modified single solution method for the determination of phosphate in natural waters.Crossref | GoogleScholarGoogle Scholar |
Poyck, S., Hendrikx, J., McMillan, H., Hreinsson, E. O., and Woods, R. (2011). Combined snow and streamflow modelling to estimate impacts of climate change on water resources in the Clutha River, New Zealand. Journal of Hydrology. New Zealand 50, 293–311.
Price, N. M., and Morel, F. M. M. (1990). Cadmium and cobalt substitution for zinc in a marine diatom. Nature 344, 658–660.
| Cadmium and cobalt substitution for zinc in a marine diatom.Crossref | GoogleScholarGoogle Scholar |
Roshan, S., Wu, J. F., and DeVries, T. (2017). Controls on the cadmium–phosphate relationship in the tropical South Pacific. Global Biogeochemical Cycles 31, 1516–1527.
| Controls on the cadmium–phosphate relationship in the tropical South Pacific.Crossref | GoogleScholarGoogle Scholar |
Rueter, J. G., and Morel, F. M. M. (1981). The interaction between zinc deficiency and copper toxicity as it affects the silicic acid uptake mechanisms in Thassiosira pseudonana. Limnology and Oceanography 26, 67–73.
| The interaction between zinc deficiency and copper toxicity as it affects the silicic acid uptake mechanisms in Thassiosira pseudonana.Crossref | GoogleScholarGoogle Scholar |
Sander, S., Hunter, K., and Frew, R. (2009). Sampling and measurement of trace metals in seawater. In ‘Practical Guidelines for the Analysis of Seawater’. (Ed. O. Wurl.) pp. 305–327. (CRC Press: Boca Raton, FL, USA.)
Sarmiento, J. L., Gruber, N., Brzezinski, M. A., and Dunne, J. P. (2004). High-latitude controls of thermocline nutrients and low latitude biological productivity. Nature 427, 56–60.
| High-latitude controls of thermocline nutrients and low latitude biological productivity.Crossref | GoogleScholarGoogle Scholar | 14702082PubMed |
Smith, J. D., and Milne, P. J. (1981). Spectrophotometric determination of silicate in natural waters by formation of [α]-molybdosilicic acid and reduction with a tin(IV)–ascorbic acid–oxalic acid mixture. Analytica Chimica Acta 123, 263–270.
| Spectrophotometric determination of silicate in natural waters by formation of [α]-molybdosilicic acid and reduction with a tin(IV)–ascorbic acid–oxalic acid mixture.Crossref | GoogleScholarGoogle Scholar |
Smith, R. O., Vennell, R., Bostock, H. C., and Williams, M. J. M. (2013). Interaction of the subtropical front with topography around southern New Zealand. Deep-sea Research – I. Oceanographic Research Papers 76, 13–26.
| Interaction of the subtropical front with topography around southern New Zealand.Crossref | GoogleScholarGoogle Scholar |
Sunda, W. G., and Huntsman, S. A. (1992). Feedback interactions between zinc and phytoplankton in seawater. Limnology and Oceanography 37, 25–40.
| Feedback interactions between zinc and phytoplankton in seawater.Crossref | GoogleScholarGoogle Scholar |
Sunda, W. G., and Huntsman, S. A. (1995). Cobalt and zinc interreplacement in marine phytoplankton: Biological and geochemical implications. Limnology and Oceanography 40, 1404–1417.
| Cobalt and zinc interreplacement in marine phytoplankton: Biological and geochemical implications.Crossref | GoogleScholarGoogle Scholar |
Sutton, P. J. H. (2003). The Southland Current: a subantarctic current. New Zealand Journal of Marine and Freshwater Research 37, 645–652.
| The Southland Current: a subantarctic current.Crossref | GoogleScholarGoogle Scholar |
Takeda, S. (1998). Influence of iron availability on nutrient consumption ratio of diatoms in oceanic waters. Nature 393, 774–777.
| Influence of iron availability on nutrient consumption ratio of diatoms in oceanic waters.Crossref | GoogleScholarGoogle Scholar |
Thamatrakoln, K., and Hildebrand, M. (2008). Silicon uptake in diatoms revisited: a model for saturable and nonsaturable uptake kinetics and the role of silicon transporters. Plant Physiology 146, 1397–1407.
| Silicon uptake in diatoms revisited: a model for saturable and nonsaturable uptake kinetics and the role of silicon transporters.Crossref | GoogleScholarGoogle Scholar | 18162598PubMed |
Tian, F., Frew, R. D., Sander, S., Hunter, K. A., and Ellwood, M. J. (2006). Organic iron(III) speciation in surface transects across a frontal zone: the Chatham Rise, New Zealand. Marine and Freshwater Research 57, 533–544.
| Organic iron(III) speciation in surface transects across a frontal zone: the Chatham Rise, New Zealand.Crossref | GoogleScholarGoogle Scholar |
Van Hale, R., and Frew, R. D. (2010). Rayleigh distillation equations applied to isotopic evolution of organic nitrogen across a continental shelf. Marine and Freshwater Research 61, 369–378.
| Rayleigh distillation equations applied to isotopic evolution of organic nitrogen across a continental shelf.Crossref | GoogleScholarGoogle Scholar |
Wu, J. F., and Roshan, S. (2015). Cadmium in the North Atlantic: implication for global cadmium-phosphorus relationship. Deep-sea Research – II. Topical Studies in Oceanography 116, 226–239.
| Cadmium in the North Atlantic: implication for global cadmium-phosphorus relationship.Crossref | GoogleScholarGoogle Scholar |
Xu, Y., Feng, L., Jeffrey, P. D., Shi, Y. G., and Morel, F. M. M. (2008). Structure and metal exchange in the cadmium carbonic anhydrase of marine diatoms. Nature 452, 56–61.
| Structure and metal exchange in the cadmium carbonic anhydrase of marine diatoms.Crossref | GoogleScholarGoogle Scholar | 18322527PubMed |
