| Autor: |
Zolkos S; Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada., Krabbenhoft DP; Upper Midwest Water Science Center, Mercury Research Laboratory, United States Geological Survey, Middleton, Wisconsin 53562, United States., Suslova A; Woods Hole Research Center, Woods Hole, Massachusetts 02540, United States., Tank SE; Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada., McClelland JW; Marine Science Institute, University of Texas at Austin, Port Aransas, Texas 78373, United States., Spencer RGM; Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, Florida 32306, United States., Shiklomanov A; Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire 03824, United States., Zhulidov AV; South Russia Centre for Preparation and Implementation of International Projects, Rostov-on-Don 344090, Russia., Gurtovaya T; South Russia Centre for Preparation and Implementation of International Projects, Rostov-on-Don 344090, Russia., Zimov N; Northeast Science Station, Far Eastern Branch of Russian Academy of Science, Chersky 690041, Russia., Zimov S; Northeast Science Station, Far Eastern Branch of Russian Academy of Science, Chersky 690041, Russia., Mutter EA; Yukon River Inter-Tribal Watershed Council, Anchorage, Alaska 99501, United States., Kutny L; Les Kutny Consultant, Inuvik, Northwest Territories X0E 0T0, Canada., Amos E; Western Arctic Research Centre, Inuvik, Northwest Territories X0E 0T0, Canada., Holmes RM; Woods Hole Research Center, Woods Hole, Massachusetts 02540, United States. |
| Abstrakt: |
Land-ocean linkages are strong across the circumpolar north, where the Arctic Ocean accounts for 1% of the global ocean volume and receives more than 10% of the global river discharge. Yet estimates of Arctic riverine mercury (Hg) export constrained from direct Hg measurements remain sparse. Here, we report results from a coordinated, year-round sampling program that focused on the six major Arctic rivers to establish a contemporary (2012-2017) benchmark of riverine Hg export. We determine that the six major Arctic rivers exported an average of 20 000 kg y -1 of total Hg (THg, all forms of Hg). Upscaled to the pan-Arctic, we estimate THg flux of 37 000 kg y -1 . More than 90% of THg flux occurred during peak river discharge in spring and summer. Normalizing fluxes to watershed area (yield) reveals higher THg yields in regions where greater denudation likely enhances Hg mobilization. River discharge, suspended sediment, and dissolved organic carbon predicted THg concentration with moderate fidelity, while suspended sediment and water yields predicted THg yield with high fidelity. These findings establish a benchmark in the face of rapid Arctic warming and an intensifying hydrologic cycle, which will likely accelerate Hg cycling in tandem with changing inputs from thawing permafrost and industrial activity. |
