Large-scale distribution of Atlantic nitrogen fixation controlled by iron availability Export

@article{citeulike:6056951, abstract = {Oceanic fixed-nitrogen concentrations are controlled by the balance between nitrogen fixation and denitrification1, 2, 3, 4. A number of factors, including iron limitation5, 6, 7, can restrict nitrogen fixation, introducing the potential for decoupling of nitrogen inputs and losses2, 5, 8. Such decoupling could significantly affect the oceanic fixed-nitrogen inventory and consequently the biological component of ocean carbon storage and hence air–sea partitioning of carbon dioxide2, 5, 8, 9. However, the extent to which nutrients limit nitrogen fixation in the global ocean is uncertain. Here, we examined rates of nitrogen fixation and nutrient concentrations in the surface waters of the Atlantic Ocean along a north–south 10,000 km transect during October and November 2005. We show that rates of nitrogen fixation were markedly higher in the North Atlantic compared with the South Atlantic Ocean. Across the two basins, nitrogen fixation was positively correlated with dissolved iron and negatively correlated with dissolved phosphorus concentrations. We conclude that inter-basin differences in nitrogen fixation are controlled by iron supply rather than phosphorus availability. Analysis of the nutrient content of deep waters suggests that the fixed nitrogen enters North Atlantic Deep Water. Our study thus supports the suggestion that iron significantly influences nitrogen fixation5, and that subsequent interactions with ocean circulation patterns contribute to the decoupling of nitrogen fixation and loss2, 4, 8.}, author = {Mark Moore, C. and Mills, Matthew M. and Achterberg, Eric P. and Geider, Richard J. and LaRoche, Julie and Lucas, Mike I. and McDonagh, Elaine L. and Pan, Xi and Poulton, Alex J. and Rijkenberg, Micha J. A. and Suggett, David J. and Ussher, Simon J. and Woodward}, citeulike-article-id = {6056951}, citeulike-linkout-0 = {http://dx.doi.org/10.1038/ngeo667}, citeulike-linkout-1 = {http://dx.doi.org/10.1038/ngeo667}, day = {01}, doi = {10.1038/ngeo667}, issn = {1752-0894}, journal = {Nature Geoscience}, keywords = {atlantic, biogeochemistry, climate, iron, nadw, nutrient, ocean, phosphorus}, month = {November}, posted-at = {2009-11-02 17:18:33}, priority = {2}, publisher = {Nature Publishing Group}, title = {Large-scale distribution of Atlantic nitrogen fixation controlled by iron availability}, url = {http://dx.doi.org/10.1038/ngeo667}, volume = {advance online publication}, year = {2009} }

TY - JOUR ID - citeulike:6056951 L3 - citeulike-article-id:6056951 N2 - Oceanic fixed-nitrogen concentrations are controlled by the balance between nitrogen fixation and denitrification1, 2, 3, 4. A number of factors, including iron limitation5, 6, 7, can restrict nitrogen fixation, introducing the potential for decoupling of nitrogen inputs and losses2, 5, 8. Such decoupling could significantly affect the oceanic fixed-nitrogen inventory and consequently the biological component of ocean carbon storage and hence air–sea partitioning of carbon dioxide2, 5, 8, 9. However, the extent to which nutrients limit nitrogen fixation in the global ocean is uncertain. Here, we examined rates of nitrogen fixation and nutrient concentrations in the surface waters of the Atlantic Ocean along a north–south 10,000 km transect during October and November 2005. We show that rates of nitrogen fixation were markedly higher in the North Atlantic compared with the South Atlantic Ocean. Across the two basins, nitrogen fixation was positively correlated with dissolved iron and negatively correlated with dissolved phosphorus concentrations. We conclude that inter-basin differences in nitrogen fixation are controlled by iron supply rather than phosphorus availability. Analysis of the nutrient content of deep waters suggests that the fixed nitrogen enters North Atlantic Deep Water. Our study thus supports the suggestion that iron significantly influences nitrogen fixation5, and that subsequent interactions with ocean circulation patterns contribute to the decoupling of nitrogen fixation and loss2, 4, 8. JF - Nature Geoscience SN - 1752-0894 TI - Large-scale distribution of Atlantic nitrogen fixation controlled by iron availability PB - Nature Publishing Group VL - advance online publication KW - atlantic KW - biogeochemistry KW - climate KW - iron KW - nadw KW - nutrient KW - ocean KW - phosphorus AU - Mark Moore, C AU - Mills, Matthew AU - Achterberg, Eric AU - Geider, Richard AU - LaRoche, Julie AU - Lucas, Mike AU - McDonagh, Elaine AU - Pan, Xi AU - Poulton, Alex AU - Rijkenberg, Micha AU - Suggett, David AU - Ussher, Simon AU - Woodward PY - 2009/11/01/ UR - http://dx.doi.org/10.1038/ngeo667 ER -