Bioassay incubation experiments conducted with nutrients and local atmospheric aerosol amendments indicate that phosphorus (P) availability limited phytoplankton growth in the low-nutrient low-chlorophyll (LNLC) ocean off Barbados. Atmospheric deposition provides a relatively large influx of new nutrients and trace metals to the surface ocean in this region in comparison to other nutrient sources. However, the impact on native phytoplankton is muted due to the high ratio of nitrogen (N) to P (NO3:SRP > 40) and the low P solubility of these aerosols. Atmospheric deposition induces P limitation in this LNLC region by adding more N and iron (Fe) relative to P. This favors the growth of Prochlorococcus, a genus characterized by low P requirements and highly efficient P acquisition mechanisms. A global three-dimensional marine ecosystem model that includes species-specific phytoplankton elemental quotas/stoichiometry and the atmospheric deposition of N, P, and Fe supports this conclusion. Future increases in aerosol N loading may therefore influence phytoplankton community structure in other LNLC areas, thereby affecting the biological pump and associated carbon sequestration. �2016. American Geophysical Union. All Rights Reserved.
Earth and Planetary Sciences Department, University of Santa Cruz, Santa Cruz, CA, United States; Department of Earth System Science, University of California, Irvine, CA, United States; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, United States; Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States
Recommended Citation:
Chien C,-T,, Mackey K,et al. Effects of African dust deposition on phytoplankton in the western tropical Atlantic Ocean off Barbados[J]. Global Biogeochemical Cycles,2016-01-01,30(5)