Articles | Volume 17, issue 2
Research article 22 Jan 2020
Research article | 22 Jan 2020
Organic iron complexes enhance iron transport capacity along estuarine salinity gradients of Baltic estuaries
Simon David Herzog et al.
No articles found.
Laurie M. Charrieau, Karl Ljung, Frederik Schenk, Ute Daewel, Emma Kritzberg, and Helena L. Filipsson
Biogeosciences, 16, 3835–3852,Short summary
We reconstructed environmental changes in the Öresund during the last 200 years, using foraminifera (microfossils), sediment, and climate data. Five zones were identified, reflecting oxygen, salinity, food content, and pollution levels for each period. The largest changes occurred ~ 1950, towards stronger currents. The foraminifera responded quickly (< 10 years) to the changes. Moreover, they did not rebound when the system returned to the previous pattern, but displayed a new equilibrium state.
Wytze K. Lenstra, Matthias Egger, Niels A. G. M. van Helmond, Emma Kritzberg, Daniel J. Conley, and Caroline P. Slomp
Biogeosciences, 15, 6979–6996,Short summary
We show that burial rates of phosphorus (P) in an estuary in the northern Baltic Sea are very high. We demonstrate that at high sedimentation rates, P retention in the sediment is related to the formation of vivianite. With a reactive transport model, we assess the sensitivity of sedimentary vivianite formation. We suggest that enrichments of iron and P in the sediment are linked to periods of enhanced riverine input of Fe, which subsequently strongly enhances P burial in coastal sediments.
Ana R. A. Soares, Ann-Kristin Bergström, Ryan A. Sponseller, Joanna M. Moberg, Reiner Giesler, Emma S. Kritzberg, Mats Jansson, and Martin Berggren
Biogeosciences, 14, 1527–1539,
Raquel Vaquer-Sunyer, Heather E. Reader, Saraladevi Muthusamy, Markus V. Lindh, Jarone Pinhassi, Daniel J. Conley, and Emma S. Kritzberg
Biogeosciences, 13, 4751–4765,Short summary
Nitrogen-rich dissolved organic matter inputs from wastewater treatment plant effluents increased bacterial production and decreased primary production and community respiration. Nutrient amendments and seasonally variable environmental conditions lead to shifts in bacterial community composition. Increases in bacterial production and simultaneous decreases in primary production lead to more carbon being consumed in the microbial loop and reduce its availability to sustain the food web.
H. E. Reader, C. A. Stedmon, and E. S. Kritzberg
Biogeosciences, 11, 3409–3419,
Related subject area
Biogeochemistry: Land - Sea CouplingEnrichment of trace metals from acid sulfate soils in sediments of the Kvarken Archipelago, eastern Gulf of Bothnia, Baltic SeaSpatio-temporal variations of lateral and atmospheric carbon fluxes from the Danube DeltaTechnical note: Seamless gas measurements across Land-Ocean Aquatic Continuum – corrections and evaluation of sensor data for CO2, CH4 and O2 from field deployments in contrasting environmentsParticulate organic matter controls benthic microbial N retention and N removal in contrasting estuaries of the Baltic SeaExport fluxes of dissolved inorganic carbon to the northern Indian Ocean from the Indian monsoonal riversThe ballast effect of lithogenic matter and its influences on the carbon fluxes in the Indian OceanIntegrating multimedia models to assess nitrogen losses from the Mississippi River basin to the Gulf of MexicoReconciling drainage and receiving basin signatures of the Godavari River systemImpacts of flocculation on the distribution and diagenesis of iron in boreal estuarine sedimentsSources, fluxes, and behaviors of fluorescent dissolved organic matter (FDOM) in the Nakdong River Estuary, KoreaEffects of changes in nutrient loading and composition on hypoxia dynamics and internal nutrient cycling of a stratified coastal lagoonCarbon degradation in agricultural soils flooded with seawater after managed coastal realignmentA global hotspot for dissolved organic carbon in hypermaritime watersheds of coastal British ColumbiaNitrogen transformations along a shallow subterranean estuaryModelling nutrient retention in the coastal zone of an eutrophic seaPatterns and persistence of hydrologic carbon and nutrient export from collapsing upland permafrostModelling the impact of riverine DON removal by marine bacterioplankton on primary production in the Arctic OceanSeasonal response of air–water CO2 exchange along the land–ocean aquatic continuum of the northeast North American coast.Quantification of iron-rich volcanogenic dust emissions and deposition over the ocean from Icelandic dust sourcesEffects of seabird nitrogen input on biomass and carbon accumulation after 50 years of primary succession on a young volcanic island, SurtseyImpact of river discharge, upwelling and vertical mixing on the nutrient loading and productivity of the Canadian Beaufort ShelfSeasonal contribution of terrestrial organic matter and biological oxygen demand to the Baltic Sea from three contrasting river catchmentsAntarctic ice sheet fertilises the Southern OceanNutrient dynamics in tropical rivers, lagoons, and coastal ecosystems of eastern Hainan Island, South China SeaBioavailability of riverine dissolved organic matter in three Baltic Sea estuaries and the effect of catchment land useSeasonal dissolved inorganic nitrogen and phosphorus budgets for two sub-tropical estuaries in south Florida, USAExport of 134 Cs and 137 Cs in the Fukushima river systems at heavy rains by Typhoon Roke in September 2011The fate of riverine nutrients on Arctic shelvesExternal forcings, oceanographic processes and particle flux dynamics in Cap de Creus submarine canyon, NW Mediterranean SeaRadium-based estimates of cesium isotope transport and total direct ocean discharges from the Fukushima Nuclear Power Plant accidentTracing inputs of terrestrial high molecular weight dissolved organic matter within the Baltic Sea ecosystemThe role of alkalinity generation in controlling the fluxes of CO2 during exposure and inundation on tidal flatsCoupling of fog and marine microbial content in the near-shore coastal environmentSpatialized N budgets in a large agricultural Mediterranean watershed: high loading and low transferEffects of water discharge and sediment load on evolution of modern Yellow River Delta, China, over the period from 1976 to 2009Carbon isotopes and lipid biomarker investigation of sources, transport and degradation of terrestrial organic matter in the Buor-Khaya Bay, SE Laptev SeaContribution of riverine nutrients to the silicon biogeochemistry of the global ocean – a model studyMolecular and radiocarbon constraints on sources and degradation of terrestrial organic carbon along the Kolyma paleoriver transect, East Siberian SeaImpact of changes in river fluxes of silica on the global marine silicon cycle: a model comparison
Joonas J. Virtasalo, Peter Österholm, Aarno T. Kotilainen, and Mats E. Åström
Biogeosciences, 17, 6097–6113,Short summary
Rivers draining the acid sulphate soils of western Finland deliver large amounts of metals (e.g. Cd, Co, Cu, La, Mn, Ni, and Zn) to the coastal sea. To better understand metal enrichment in the sea floor, we analysed metal contents and grain size distribution in nine sediment cores, which increased in the 1960s and 1970s and stayed at high levels afterwards. The enrichment is visible more than 25 km out from the river mouths. Organic aggregates are suggested as the key seaward metal carriers.
Marie-Sophie Maier, Cristian R. Teodoru, and Bernhard Wehrli
Revised manuscript accepted for BGShort summary
Based on a 2-year monitoring study, we found that the freshwater system of the Danube Delta, Romania, releases carbon dioxide and methane to the atmosphere. The amount of carbon released depends on the freshwater feature (river branches, channels, lakes), season and hydrologic condition, affecting the exchange with the wetland. Spatial upscaling should therefore consider these factors. Furthermore, the Danube Delta increases the amount of carbon reaching the Black Sea via the Danube River.
Anna Canning, Arne Körtzinger, Peer Fietzek, and Gregor Rehder
Revised manuscript accepted for BGShort summary
The manuscript describes a novel, fully autonomous, multi-gas flow-through setup for multiple gases that combines established high-quality oceanographic sensors in a small and robust system, designed to use across all salinities from all types of platforms. We describe the system and its performance in all relevant detail, including corrections, which improve the accuracy of these sensors. Illustrating how simultaneous multi-gas set up can provide extremely high spatiotemporal resolution.
Ines Bartl, Dana Hellemann, Christophe Rabouille, Kirstin Schulz, Petra Tallberg, Susanna Hietanen, and Maren Voss
Biogeosciences, 16, 3543–3564,Short summary
Irrespective of variable environmental settings in estuaries, the quality of organic particles is an important factor controlling microbial processes that facilitate a reduction of land-derived nitrogen loads to the open sea. Through the interplay of biogeochemical processing, geomorphology, and hydrodynamics, organic particles may function as a carrier and temporary reservoir of nitrogen, which has a major impact on the efficiency of nitrogen load reduction.
Moturi S. Krishna, Rongali Viswanadham, Mamidala H. K. Prasad, Vuravakonda R. Kumari, and Vedula V. S. S. Sarma
Biogeosciences, 16, 505–519,Short summary
An order-of-magnitude variability in DIC was found within the Indian estuaries due to significant variability in size of rivers, precipitation pattern and lithology in the catchments. Indian monsoonal estuaries annually export ∼ 10.3 Tg of DIC to the northern Indian Ocean, of which 75 % enters into the Bay of Bengal. Our results indicated that chemical weathering of carbonate and silicate minerals by soil CO2 is the major source of DIC in the Indian monsoonal rivers.
Tim Rixen, Birgit Gaye, Kay-Christian Emeis, and Venkitasubramani Ramaswamy
Biogeosciences, 16, 485–503,Short summary
Data obtained from sediment trap experiments in the Indian Ocean indicate that lithogenic matter ballast increases organic carbon flux rates on average by 45 % and by up to 62 % at trap locations in the river-influenced regions of the Indian Ocean. Such a strong lithogenic matter ballast effect implies that land use changes and the associated enhanced transport of lithogenic matter may significantly affect the CO2 uptake of the organic carbon pump in the receiving ocean areas.
Yongping Yuan, Ruoyu Wang, Ellen Cooter, Limei Ran, Prasad Daggupati, Dongmei Yang, Raghavan Srinivasan, and Anna Jalowska
Biogeosciences, 15, 7059–7076,Short summary
Elevated levels of nutrients in surface water, which originate from deposition of atmospheric N, drainage from agricultural fields, and discharges from sewage treatment plants, cause explosive algal blooms that impair water quality. The complex cycling of nutrients through the land, air, and water requires an integrated multimedia modeling system linking air, land surface, and stream processes to assess their sources, transport, and transformation in large river basins for decision making.
Muhammed Ojoshogu Usman, Frédérique Marie Sophie Anne Kirkels, Huub Michel Zwart, Sayak Basu, Camilo Ponton, Thomas Michael Blattmann, Michael Ploetze, Negar Haghipour, Cameron McIntyre, Francien Peterse, Maarten Lupker, Liviu Giosan, and Timothy Ian Eglinton
Biogeosciences, 15, 3357–3375,
Tom Jilbert, Eero Asmala, Christian Schröder, Rosa Tiihonen, Jukka-Pekka Myllykangas, Joonas J. Virtasalo, Aarno Kotilainen, Pasi Peltola, Päivi Ekholm, and Susanna Hietanen
Biogeosciences, 15, 1243–1271,Short summary
Iron is a common dissolved element in river water, recognizable by its orange-brown colour. Here we show that when rivers reach the ocean much of this iron settles to the sediments by a process known as flocculation. The iron is then used by microbes in coastal sediments, which are important hotspots in the global carbon cycle.
Shin-Ah Lee and Guebuem Kim
Biogeosciences, 15, 1115–1122,Short summary
The fluorescent dissolved organic matter (FDOM) delivered from riverine discharges significantly affects carbon and biogeochemical cycles in coastal waters. Our results show that the terrestrial concentrations of humic-like FDOM in river water were 60–80 % higher in the summer and fall, while the in situ production of protein-like FDOM was 70–80 % higher in the spring. Our results suggest that there are large seasonal changes in riverine fluxes of FDOM components to the ocean.
Yafei Zhu, Andrew McCowan, and Perran L. M. Cook
Biogeosciences, 14, 4423–4433,Short summary
We used a 3-D coupled hydrodynamic–biogeochemical water quality model to investigate the effects of changes in catchment nutrient loading and composition on the phytoplankton dynamics, development of hypoxia and internal nutrient dynamics in a stratified coastal lagoon system. The results highlighted the need to reduce both total nitrogen and total phosphorus for water quality improvement in estuarine systems.
Kamilla S. Sjøgaard, Alexander H. Treusch, and Thomas B. Valdemarsen
Biogeosciences, 14, 4375–4389,Short summary
Permanent flooding of low-lying coastal areas is a growing threat due to climate-change-related sea-level rise. To reduce coastal damage, buffer zones can be created by managed coastal realignment where existing dykes are breached and new dykes are built further inland. We studied the impacts on organic matter degradation in soils flooded with seawater by managed coastal realignment and suggest that most of the organic carbon present in coastal soils will be permanently preserved after flooding.
Allison A. Oliver, Suzanne E. Tank, Ian Giesbrecht, Maartje C. Korver, William C. Floyd, Paul Sanborn, Chuck Bulmer, and Ken P. Lertzman
Biogeosciences, 14, 3743–3762,Short summary
Rivers draining small watersheds of the outer coastal Pacific temperate rainforest export some of the highest yields of dissolved organic carbon (DOC) in the world directly to the ocean. This DOC is largely derived from soils and terrestrial plants. Rainfall, temperature, and watershed characteristics such as wetlands and lakes are important controls on DOC export. This region may be significant for carbon export and linking terrestrial carbon to marine ecosystems.
Mathilde Couturier, Gwendoline Tommi-Morin, Maude Sirois, Alexandra Rao, Christian Nozais, and Gwénaëlle Chaillou
Biogeosciences, 14, 3321–3336,Short summary
At the land–ocean interface, subterranean estuaries (STEs) are a critical transition pathway of nitrogen. Environmental conditions in the groundwater lead to nitrogen transformation, altering the nitrogen species and concentrations exported to the coastal ocean. This study highlights the role of a STE in processing groundwater-derived N in a shallow boreal STE, far from anthropogenic pressures. Biogeochemical transformations provide new N species from terrestrial origin to the coastal ocean.
Elin Almroth-Rosell, Moa Edman, Kari Eilola, H. E. Markus Meier, and Jörgen Sahlberg
Biogeosciences, 13, 5753–5769,Short summary
Nutrients from land have been discussed to increase eutrophication in the open sea. This model study shows that the coastal zone works as an efficient filter. Water depth and residence time regulate the retention that occurs mostly in the sediment due to processes such as burial and denitrification. On shorter timescales the retention capacity might seem less effective when the land load of nutrients decreases, but with time the coastal zone can import nutrients from the open sea.
B. W. Abbott, J. B. Jones, S. E. Godsey, J. R. Larouche, and W. B. Bowden
Biogeosciences, 12, 3725–3740,Short summary
As high latitudes warm, carbon and nitrogen stored in permafrost soil will be vulnerable to erosion and transport to Arctic streams and rivers. We sampled outflow from 83 permafrost collapse features in Alaska. Permafrost collapse caused substantial increases in dissolved organic carbon and inorganic nitrogen but decreased methane concentration by 90%. Upland thermokarst may be a dominant linkage transferring carbon and nutrients from terrestrial to aquatic ecosystems as the Arctic warms.
V. Le Fouest, M. Manizza, B. Tremblay, and M. Babin
Biogeosciences, 12, 3385–3402,
G. G. Laruelle, R. Lauerwald, J. Rotschi, P. A. Raymond, J. Hartmann, and P. Regnier
Biogeosciences, 12, 1447–1458,Short summary
This study quantifies the exchange of carbon dioxide (CO2) between the atmosphere and the land-ocean aquatic continuum (LOAC) of the northeast North American coast, which consists of rivers, estuaries, and the coastal ocean. Our analysis reveals significant variations of the flux intensity both in time and space across the study area. Ice cover, snowmelt, and the intensity of the estuarine filter are identified as important control factors of the CO2 exchange along the LOAC.
O. Arnalds, H. Olafsson, and P. Dagsson-Waldhauserova
Biogeosciences, 11, 6623–6632,Short summary
Iceland is one of the largest dust sources on Earth. Based on two separate methods, we estimate dust emissions to range between 30 and 40 million tons annually. Ocean deposition ranges between 5.5 and 13.8 million tons. Calculated iron deposition in oceans around Iceland ranges between 0.56 to 1.4 million tons, which are distributed over wide areas. Iron is a limiting nutrient for primary production in these waters, and dust is likely to affect oceanic Fe levels around Iceland.
N. I. W. Leblans, B. D. Sigurdsson, P. Roefs, R. Thuys, B. Magnússon, and I. A. Janssens
Biogeosciences, 11, 6237–6250,Short summary
We studied the influence of allochthonous N inputs on primary succession and soil development of a 50-year-old volcanic island, Surtsey. Seabirds increased the ecosystem N accumulation rate inside their colony to ~47 kg ha-1 y-1, compared to 0.7 kg ha-1 y-1 outside it. A strong relationship was found between total ecosystem N stock and both total above- and belowground biomass and SOC stock, which shows how fast external N input can boost primary succession and soil formation.
J.-É. Tremblay, P. Raimbault, N. Garcia, B. Lansard, M. Babin, and J. Gagnon
Biogeosciences, 11, 4853–4868,
H. E. Reader, C. A. Stedmon, and E. S. Kritzberg
Biogeosciences, 11, 3409–3419,
R. Death, J. L. Wadham, F. Monteiro, A. M. Le Brocq, M. Tranter, A. Ridgwell, S. Dutkiewicz, and R. Raiswell
Biogeosciences, 11, 2635–2643,
R. H. Li, S. M. Liu, Y. W. Li, G. L. Zhang, J. L. Ren, and J. Zhang
Biogeosciences, 11, 481–506,
E. Asmala, R. Autio, H. Kaartokallio, L. Pitkänen, C. A. Stedmon, and D. N. Thomas
Biogeosciences, 10, 6969–6986,
C. Buzzelli, Y. Wan, P. H. Doering, and J. N. Boyer
Biogeosciences, 10, 6721–6736,
S. Nagao, M. Kanamori, S. Ochiai, S. Tomihara, K. Fukushi, and M. Yamamoto
Biogeosciences, 10, 6215–6223,
V. Le Fouest, M. Babin, and J.-É. Tremblay
Biogeosciences, 10, 3661–3677,
A. Rumín-Caparrós, A. Sanchez-Vidal, A. Calafat, M. Canals, J. Martín, P. Puig, and R. Pedrosa-Pàmies
Biogeosciences, 10, 3493–3505,
M. A. Charette, C. F. Breier, P. B. Henderson, S. M. Pike, I. I. Rypina, S. R. Jayne, and K. O. Buesseler
Biogeosciences, 10, 2159–2167,
B. Deutsch, V. Alling, C. Humborg, F. Korth, and C. M. Mörth
Biogeosciences, 9, 4465–4475,
P. A. Faber, A. J. Kessler, J. K. Bull, I. D. McKelvie, F. J. R. Meysman, and P. L. M. Cook
Biogeosciences, 9, 4087–4097,
M. E. Dueker, G. D. O'Mullan, K. C. Weathers, A. R. Juhl, and M. Uriarte
Biogeosciences, 9, 803–813,
L. Lassaletta, E. Romero, G. Billen, J. Garnier, H. García-Gómez, and J. V. Rovira
Biogeosciences, 9, 57–70,
J. Yu, Y. Fu, Y. Li, G. Han, Y. Wang, D. Zhou, W. Sun, Y. Gao, and F. X. Meixner
Biogeosciences, 8, 2427–2435,
E. S. Karlsson, A. Charkin, O. Dudarev, I. Semiletov, J. E. Vonk, L. Sánchez-García, A. Andersson, and Ö. Gustafsson
Biogeosciences, 8, 1865–1879,
C. Y. Bernard, H. H. Dürr, C. Heinze, J. Segschneider, and E. Maier-Reimer
Biogeosciences, 8, 551–564,
J. E. Vonk, L. Sánchez-García, I. Semiletov, O. Dudarev, T. Eglinton, A. Andersson, and Ö. Gustafsson
Biogeosciences, 7, 3153–3166,
C. Y. Bernard, G. G. Laruelle, C. P. Slomp, and C. Heinze
Biogeosciences, 7, 441–453,
Abesser, C., Robinson, R., and Soulsby, C.: Iron and manganese cycling in the storm runoff of a Scottish upland catchment, J. Hydrol., 326, 59–78, 2006.
Andersson, K., Dahlqvist, R., Turner, D., Stolpe, B., Larsson, T., Ingri, J., and Andersson, P.: Colloidal rare earth elements in a boreal river: changing sources and distributions during the spring flood, Geochim. Cosmochim. Ac., 70, 3261–3274, 2006.
Batchelli, S., Muller, F. L., Chang, K.-C., and Lee, C.-L.: Evidence for strong but dynamic iron- humic colloidal associations in humic-rich coastal waters, Environ. Sci. Technol., 44, 8485–8490, 2010.
Björnerås, C., Weyhenmeyer, G. A., Evans, C. D., Gessner, M. O., Grossart, H. P., Kangur, K., Kokorite, I., Kortelainen, P., Laudon, H., and Lehtoranta, J.: Widespread increases in iron concentration in European and North American freshwaters, Global Biogeochem. Cy., 31, 1488–1500, 2017.
Bordas, F. and Bourg, A. C.: A critical evaluation of sample pretreatment for storage of contaminated sediments to be investigated for the potential mobility of their heavy metal load, Water Air Soil Poll., 103, 137–149, 1998.
Boyle, E., Edmond, J., and Sholkovitz, E.: The mechanism of iron removal in estuaries, Geochim. Cosmochim. Ac., 41, 1313–1324, 1977.
Breitbarth, E., Achterberg, E. P., Ardelan, M. V., Baker, A. R., Bucciarelli, E., Chever, F., Croot, P. L., Duggen, S., Gledhill, M., Hassellöv, M., Hassler, C., Hoffmann, L. J., Hunter, K. A., Hutchins, D. A., Ingri, J., Jickells, T., Lohan, M. C., Nielsdóttir, M. C., Sarthou, G., Schoemann, V., Trapp, J. M., Turner, D. R., and Ye, Y.: Iron biogeochemistry across marine systems – progress from the past decade, Biogeosciences, 7, 1075–1097, https://doi.org/10.5194/bg-7-1075-2010, 2010.
Dahlqvist, R., Andersson, K., Ingri, J., Larsson, T., Stolpe, B., and Turner, D.: Temporal variations of colloidal carrier phases and associated trace elements in a boreal river, Geochim. Cosmochim. Ac., 71, 5339–5354, 2007.
Ekström, S. M., Regnell, O., Reader, H. E., Nilsson, P. A., Löfgren, S., and Kritzberg, E. S.: Increasing concentrations of iron in surface waters as a consequence of reducing conditions in the catchment area, J. Geophys. Res.-Biogeo., 121, 479–493, 2016.
Forsgren, G. and Jansson, M.: The turnover of river-transported iron, phosphorus and organic carbon in the Öre estuary, northern Sweden, in: Sediment/Water Interactions, Springer, 585–596, 1992.
Forsgren, G., Jansson, M., and Nilsson, P.: Aggregation and sedimentation of iron, phosphorus and organic carbon in experimental mixtures of freshwater and estuarine water, Estuar. Coast. Shelf S., 43, 259–268, 1996.
Fujii, M., Ito, H., Rose, A. L., Waite, T. D., and Omura, T.: Transformation dynamics and reactivity of dissolved and colloidal iron in coastal waters, Mar. Chem., 110, 165–175, 2008.
Fujii, M., Dang, T., Rose, A. L., Omura, T., and Waite, T.: Effect of light on iron uptake by the freshwater cyanobacterium Microcystis aeruginosa, Environ. Sci. Technol., 45, 1391–1398, 2011.
Funke, H., Scheinost, A., and Chukalina, M.: Wavelet analysis of extended x-ray absorption fine structure data, Phys. Rev. B, 71, 094110, https://doi.org/10.1103/PhysRevB.71.094110, 2005.
Gelting, J., Breitbarth, E., Stolpe, B., Hassellöv, M., and Ingri, J.: Fractionation of iron species and iron isotopes in the Baltic Sea euphotic zone, Biogeosciences, 7, 2489–2508, https://doi.org/10.5194/bg-7-2489-2010, 2010.
Glatzel, P. and Bergmann, U.: High resolution 1s core hole X-ray spectroscopy in 3d transition metal complexes – electronic and structural information, Coordin. Chem. Rev., 249, 65–95, 2005.
Gledhill, M. and Buck, K. N.: The organic complexation of iron in the marine environment: a review, Front. Microbiol., 3, 69, https://doi.org/10.3389/fmicb.2012.00069, 2012.
Grabs, T., Bishop, K., Laudon, H., Lyon, S. W., and Seibert, J.: Riparian zone hydrology and soil water total organic carbon (TOC): implications for spatial variability and upscaling of lateral riparian TOC exports, Biogeosciences, 9, 3901–3916, https://doi.org/10.5194/bg-9-3901-2012, 2012.
Gustafsson, Ö., Widerlund, A., Andersson, P. S., Ingri, J., Roos, P., and Ledin, A.: Colloid dynamics and transport of major elements through a boreal river–brackish bay mixing zone, Mar. Chem., 71, 1–21, 2000.
Haese, R. R.: The biogeochemistry of iron, in: Marine Geochemistry, Springer, 241–270, 2006.
Herzog, S. D., Persson, P., and Kritzberg, E. S.: Salinity Effects on Iron Speciation in Boreal River Waters, Environ. Sci. Technol., 51, 9747–9755, 2017.
Hölemann, J. A., Schirmacher, M., and Prange, A.: Seasonal variability of trace metals in the Lena River and the southeastern Laptev Sea: Impact of the spring freshet, Global Planet. Change, 48, 112–125, 2005.
Hunter, K. A. and Leonard, M. W.: Colloid stability and aggregation in estuaries: 1. Aggregation kinetics of riverine dissolved iron after mixing with seawater, Geochim. Cosmochim. Ac., 52, 1123–1130, 1988.
Ilina, S. M., Poitrasson, F., Lapitskiy, S. A., Alekhin, Y. V., Viers, J., and Pokrovsky, O. S.: Extreme iron isotope fractionation between colloids and particles of boreal and temperate organic-rich waters, Geochim. Cosmochim. Ac., 101, 96–111, https://doi.org/10.1016/j.gca.2012.10.023, 2013.
Ingri, J., Malinovsky, D., Rodushkin, I., Baxter, D. C., Widerlund, A., Andersson, P., Gustafsson, Ö., Forsling, W., and Öhlander, B.: Iron isotope fractionation in river colloidal matter, Earth Planet. Sc. Lett., 245, 792–798, https://doi.org/10.1016/j.epsl.2006.03.031, 2006.
Johnson, K. S., Gordon, R. M., and Coale, K. H.: What controls dissolved iron concentrations in the world ocean?, Mar. Chem., 57, 137–161, 1997.
Karlsson, T. and Persson, P.: Coordination chemistry and hydrolysis of Fe (III) in a peat humic acid studied by X-ray absorption spectroscopy, Geochim. Cosmochim. Ac., 74, 30–40, 2010.
Karlsson, T. and Persson, P.: Complexes with aquatic organic matter suppress hydrolysis and precipitation of Fe(III), Chem. Geol., 322–323, 19–27, https://doi.org/10.1016/j.chemgeo.2012.06.003, 2012.
Karlsson, T., Persson, P., Skyllberg, U., Mörth, C.-M., and Giesler, R.: Characterization of iron (III) in organic soils using extended X-ray absorption fine structure spectroscopy, Environ. Sci. Technol., 42, 5449–5454, 2008.
Klementev, K.: Statistical evaluations in fitting problems, J. Synchrotron Radiat., 8, 270–272, 2001.
Krachler, R., Jirsa, F., and Ayromlou, S.: Factors influencing the dissolved iron input by river water to the open ocean, Biogeosciences, 2, 311–315, https://doi.org/10.5194/bg-2-311-2005, 2005.
Krachler, R., Krachler, R. F., von der Kammer, F., Suphandag, A., Jirsa, F., Ayromlou, S., Hofmann, T., and Keppler, B. K.: Relevance of peat-draining rivers for the riverine input of dissolved iron into the ocean, Sci. Total Environ., 408, 2402–2408, https://doi.org/10.1016/j.scitotenv.2010.02.018, 2010.
Kraemer, S. M.: Iron oxide dissolution and solubility in the presence of siderophores, Aquat. Sci., 66, 3–18, 2004.
Kritzberg, E. S. and Ekström, S. M.: Increasing iron concentrations in surface waters – a factor behind brownification?, Biogeosciences, 9, 1465–1478, https://doi.org/10.5194/bg-9-1465-2012, 2012.
Kvashnina, K. O. and Scheinost, A. C.: A Johann-type X-ray emission spectrometer at the Rossendorf beamline, J. Synchrotron Radiat., 23, 836–841, 2016.
Laglera, L. M. and van den Berg, C. M.: Evidence for geochemical control of iron by humic substances in seawater, Limnol. Oceanogr., 54, 610–619, 2009.
Laglera, L. M., Battaglia, G., and van den Berg, C. M.: Effect of humic substances on the iron speciation in natural waters by CLE/CSV, Mar. Chem., 127, 134–143, 2011.
Lalonde, K., Mucci, A., Ouellet, A., and Gélinas, Y.: Preservation of organic matter in sediments promoted by iron, Nature, 483, 198–200, 2012.
Lenstra, W. K., Egger, M., van Helmond, N. A. G. M., Kritzberg, E., Conley, D. J., and Slomp, C. P.: Large variations in iron input to an oligotrophic Baltic Sea estuary: impact on sedimentary phosphorus burial, Biogeosciences, 15, 6979–6996, https://doi.org/10.5194/bg-15-6979-2018, 2018.
Liu, X. and Millero, F. J.: The solubility of iron in seawater, Mar. Chem., 77, 43–54, 2002.
Lofts, S., Tipping, E., and Hamilton-Taylor, J.: The chemical speciation of Fe (III) in freshwaters, Aquat. Geochem., 14, 337–358, 2008.
Lydersen, E., Löfgren, S., and Arnesen, R. T.: Metals in Scandinavian surface waters: effects of acidification, liming, and potential reacidification, Crit. Rev. Env. Sci. Tec., 32, 73–295, 2002.
Martin, J. H. and Fitzwater, S. E.: Iron deficiency limits phytoplankton growth in the north-east Pacific subarctic, Nature, 331, 341–343, 1988.
Mosley, L. M., Hunter, K. A., and Ducker, W. A.: Forces between colloid particles in natural waters, Environ. Sci. Technol., 37, 3303–3308, 2003.
Muller, F. L.: Exploring the potential role of terrestrially derived humic substances in the marine biogeochemistry of iron, Front. Earth Sci., 6, 159, https://doi.org/10.3389/feart.2018.00159, 2018.
Neff, J., Finlay, J., Zimov, S., Davydov, S., Carrasco, J., Schuur, E., and Davydova, A.: Seasonal changes in the age and structure of dissolved organic carbon in Siberian rivers and streams, Geophys. Res. Lett., 33, 2006.
Neubauer, E., Kohler, S. J., von der Kammer, F., Laudon, H., and Hofmann, T.: Effect of pH and stream order on iron and arsenic speciation in boreal catchments, Environ. Sci. Technol., 47, 7120–7128, https://doi.org/10.1021/es401193j, 2013.
Nowostawska, U., Kim, J. P., and Hunter, K. A.: Aggregation of riverine colloidal iron in estuaries: A new kinetic study using stopped-flow mixing, Mar. Chem., 110, 205–210, 2008.
O'day, P. A., Rivera, N., Root, R., and Carroll, S. A.: X-ray absorption spectroscopic study of Fe reference compounds for the analysis of natural sediments, Am. Mineral., 89, 572–585, 2004.
Persson, P. and Axe, K.: Adsorption of oxalate and malonate at the water-goethite interface: molecular surface speciation from IR spectroscopy, Geochim. Cosmochim. Ac., 69, 541–552, 2005.
Pokrovsky, O., Schott, J., and Dupré, B.: Trace element fractionation and transport in boreal rivers and soil porewaters of permafrost-dominated basaltic terrain in Central Siberia, Geochim. Cosmochim. Ac., 70, 3239–3260, 2006.
Pokrovsky, O., Viers, J., Shirokova, L., Shevchenko, V., Filipov, A., and Dupré, B.: Dissolved, suspended, and colloidal fluxes of organic carbon, major and trace elements in the Severnaya Dvina River and its tributary, Chem. Geol., 273, 136–149, 2010.
Raiswell, R., Vu, H. P., Brinza, L., and Benning, L. G.: The determination of labile Fe in ferrihydrite by ascorbic acid extraction: methodology, dissolution kinetics and loss of solubility with age and de-watering, Chem. Geol., 278, 70–79, 2010.
Rember, R. D. and Trefry, J. H.: Increased concentrations of dissolved trace metals and organic carbon during snowmelt in rivers of the alaskan arctic 1, Geochim. Cosmochim. Ac., 68, 477–489, 2004.
Sarkkola, S., Nieminen, M., Koivusalo, H., Laurén, A., Kortelainen, P., Mattsson, T., Palviainen, M., Piirainen, S., Starr, M., and Finér, L.: Iron concentrations are increasing in surface waters from forested headwater catchments in eastern Finland, Sci. Total Environ., 463–464, 683–689, https://doi.org/10.1016/j.scitotenv.2013.06.072, 2013.
Sholkovitz, E.: Flocculation of dissolved organic and inorganic matter during the mixing of river water and seawater, Geochim. Cosmochim. Ac., 40, 831–845, 1976.
Sholkovitz, E., Boyle, E., and Price, N.: The removal of dissolved humic acids and iron during estuarine mixing, Earth Planet. Sc. Lett., 40, 130–136, 1978.
Signorato, R., Solé, V. A., and Gauthier, C.: Performance of the ESRF ID26 beamline reflective optics, J. Synchrotron Radiat., 6, 176–178, https://doi.org/10.1107/S0909049598013971, 1999.
Stal, L. J., Staal, M., and Villbrandt, M.: Nutrient control of cyanobacterial blooms in the Baltic Sea, Aquat. Microb. Ecol., 18, 165–173, https://doi.org/10.3354/ame018165, 1999.
Stolpe, B. and Hassellöv, M.: Changes in size distribution of fresh water nanoscale colloidal matter and associated elements on mixing with seawater, Geochim. Cosmochim. Ac., 71, 3292–3301, https://doi.org/10.1016/j.gca.2007.04.025, 2007.
Stolpe, B., Guo, L., and Shiller, A. M.: Binding and transport of rare earth elements by organic and iron-rich nanocolloids in Alaskan rivers, as revealed by field-flow fractionation and ICP-MS, Geochim. Cosmochim. Ac., 106, 446–462, 2013.
Stolte, W., Balode, M., Carlsson, P., Grzebyk, D., Janson, S., Lips, I., Panosso, R., Ward, C. J., and Graneli, E.: Stimulation of nitrogen-fixing cyanobacteria in a Baltic Sea plankton community by land-derived organic matter or iron addition, Mar. Ecol.-Prog. Ser., 37, 71–82, 2006.
Stumm, W. and Morgan, J.: Aquatic Chemistry, Interscience, NY, 1970.
Sukekava, C., Downes, J., Slagter, H. A., Gerringa, L. J., and Laglera, L. M.: Determination of the contribution of humic substances to iron complexation in seawater by catalytic cathodic stripping voltammetry, Talanta, 189, 359–364, 2018.
Sundman, A., Karlsson, T., and Persson, P.: An experimental protocol for structural characterization of Fe in dilute natural waters, Environ. Sci. Technol., 47, 8557–8564, https://doi.org/10.1021/es304630a, 2013.
Sundman, A., Karlsson, T., Laudon, H., and Persson, P.: XAS study of iron speciation in soils and waters from a boreal catchment, Chem. Geol., 364, 93–102, https://doi.org/10.1016/j.chemgeo.2013.11.023, 2014.
Taylor, S.: Trace element abundances and the chondritic Earth model, Geochim. Cosmochim. Ac., 28, 1989–1998, 1964.
Tiller, C. L. and O'Melia, C. R.: Natural organic matter and colloidal stability: models and measurements, Colloids Surfaces A, 73, 89–102, 1993.
Tipping, E.: The adsorption of aquatic humic substances by iron oxides, Geochim. Cosmochim. Ac., 45, 191–199, 1981.
Turner, A. and Millward, G.: Suspended particles: their role in estuarine biogeochemical cycles, Estuar. Coast. Shelf S., 55, 857–883, 2002.
Turner, A., Millward, G. E., and Le Roux, S. M.: Significance of oxides and particulate organic matter in controlling trace metal partitioning in a contaminated estuary, Mar. Chem., 88, 179–192, 2004.
van Hulten, M., Middag, R., Dutay, J.-C., de Baar, H., Roy-Barman, M., Gehlen, M., Tagliabue, A., and Sterl, A.: Manganese in the west Atlantic Ocean in the context of the first global ocean circulation model of manganese, Biogeosciences, 14, 1123–1152, https://doi.org/10.5194/bg-14-1123-2017, 2017.
Vasyukova, E., Pokrovsky, O., Viers, J., Oliva, P., Dupré, B., Martin, F., and Candaudap, F.: Trace elements in organic-and iron-rich surficial fluids of the boreal zone: Assessing colloidal forms via dialysis and ultrafiltration, Geochim. Cosmochim. Ac., 74, 449–468, 2010.
Vilgé-Ritter, A., Rose, J., Masion, A., Bottero, J.-Y., and Lainé, J.-M.: Chemistry and structure of aggregates formed with Fe-salts and natural organic matter, Colloid. Surface. A, 147, 297–308, 1999.
Waite, T. D. and Morel, F. M.: Photoreductive dissolution of colloidal iron oxides in natural waters, Environ. Sci. Technol., 18, 860–868, 1984.
Wällstedt, T., Björkvald, L., and Gustafsson, J. P.: Increasing concentrations of arsenic and vanadium in (southern) Swedish streams, Appl. Geochem., 25, 1162–1175, 2010.
Waychunas, G. A., Kim, C. S., and Banfield, J. F.: Nanoparticulate iron oxide minerals in soils and sediments: unique properties and contaminant scavenging mechanisms, J. Nanopart. Res., 7, 409–433, 2005.
Webb, S.: SIXpack: a graphical user interface for XAS analysis using IFEFFIT, Phys. Scripta, T115, 1011–1014, 2005.
Weyhenmeyer, G. A., Prairie, Y. T., and Tranvik, L. J.: Browning of Boreal Freshwaters Coupled to Carbon-Iron Interactions along the Aquatic Continuum, PLoS ONE, 9, e88104, https://doi.org/10.1371/journal.pone.0088104, 2014.
Yu, C., Virtasalo, J. J., Karlsson, T., Peltola, P., Österholm, P., Burton, E. D., Arppe, L., Hogmalm, J. K., Ojala, A. E., and Åström, M. E.: Iron behavior in a northern estuary: Large pools of non-sulfidized Fe (II) associated with organic matter, Chem. Geol., 413, 73–85, 2015.
Fe concentrations in boreal rivers are increasing strongly in several regions in Northern Europe. This study focuses on how Fe speciation and interaction with organic matter affect stability of Fe across estuarine salinity gradients. The results confirm a positive relationship between the relative contribution of organically complexed Fe and stability. Moreover, organically complexed Fe was more prevalent at high flow conditions and more dominant further upstream in a catchment.
Fe concentrations in boreal rivers are increasing strongly in several regions in Northern...