Seasonal and annual fluxes of nutrients and organic matter from large rivers to the Arctic Ocean and surrounding seas

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Estuaries and Coasts 35 (2012): 369-382, doi:10.1007/s12237-011-9386-6.River inputs of nutrients and organic matter impact the biogeochemistry of arctic estuaries and the Arctic Ocean as a whole, yet there is considerable uncertainty about the magnitude of fluvial fluxes at the pan-arctic scale. Samples from the six largest arctic rivers, with a combined watershed area of 11.3 x 106 km2, have revealed strong seasonal variations in constituent concentrations and fluxes within rivers as well as large differences among the rivers. Specifically, we investigate fluxes of dissolved organic carbon, dissolved organic nitrogen, total dissolved phosphorus, dissolved inorganic nitrogen, nitrate, and silica. This is the first time that seasonal and annual constituent fluxes have been determined using consistent sampling and analytical methods at the pan arctic scale, and consequently provide the best available estimates for constituent flux from land to the Arctic Ocean and surrounding seas. Given the large inputs of river water to the relatively small Arctic Ocean, and the dramatic impacts that climate change is having in the Arctic, it is particularly urgent that we establish the contemporary river fluxes so that we will be able to detect future changes and evaluate the impact of the changes on the biogeochemistry of the receiving coastal and ocean systems.This work was supported by the National Science Foundation through grants OPP-0229302, OPP-0519840, OPP-0732522, and OPP-0732944. Additional support was provided by the U. S. Geological Survey (Yukon River) and the Department of Indian and Northern Affairs (Mackenzie River)

Metals in some dominant vascular plants, mosses, lichens, algae, and the biological soil crust in various types of terrestrial tundra, SW Spitsbergen, Norway

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Impact of platinum group element emissions from mining and production activities

South Africa and Russia are the world’s leading platinum group elements (PGE) producers with over 80 % of the global PGE output. Studies performed in the Bushveld Igneous Complex in South Africa and on the Kola Peninsula in Russia show that PGE mining and production activities are important regional PGE sources. Elevated PGE concentrations have been found in snow, soil, road dust, grass, moss and humus collected near PGE mining and production sites. The occurrence of elevated PGE concentrations near mining sites raises concern over environmental effects and exposure of the local population. Studies on the occurrence of PGE in remote environments also suggest that emissions from PGE production activities contribute to the global biogeochemical cycle of the PGE. The loss of PGE during metal production could be as much as 5 % of the global supply and represents a substantial economic loss. Studies on the impact of PGE mining and production activities are few. Further research is needed to better assess the environmental impact of PGE emissions from mining and production activities

Rapid range expansion of the invasive quagga mussel in relation to zebra mussel presence in The Netherlands and Western Europe

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