Aerosol inputs enhance new production in the subtropical northeast Atlantic

Carlos M. Duarte*, Jordi Dachs, Moira Llabrés, Patricia Alonso-Laita, Josep M. Gasol, Antonio Tovar-Sánchez, Sergio Sañudo-Wilhemy, Susana Agustí

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

77 Scopus citations

Abstract

Atmospheric deposition is an important source of limiting nutrients to the ocean, potentially stimulating oceanic biota. Atmospheric inputs can also deliver important amounts of organic matter, which may fuel heterotrophic activity in the ocean. The effect of atmospheric dry aerosol deposition on the metabolic balance and net production of planktonic communities remains unresolved. Here we report high inputs of aerosol-bound N, Si, P, Fe and organic C to the subtropical NE Atlantic and experimentally demonstrate these inputs to stimulate autotrophic abundance and metabolism far beyond the modest stimulation of heterotrophic processes, thereby enhancing new production. Aerosol dry deposition was threefold to tenfold higher in the coastal ocean than in the open ocean, and supplied high average (±SE) inputs of organic C (980 ± 220 μmol C m-2 d-1), total N (280 ± 70 μmol N m-2 d-1), Si (211 ± 39 μmol Si m-2 d-1), and labile Fe (1.01 ± 0.19 μmol Fe m-2 d-1), but low amounts of total P (8 ± 1.6 μmol P m-2 d-1) to the region during the study. Experimental aerosol inputs to oceanic planktonic communities from the studied area resulted, at the highest doses applied, in a sharp increase in phytoplankton biomass (sevenfold) and production (tenfold) within 4 days, with the community shifting from a dominance of picocyanobacteria to one of diatoms. In contrast, bacterial abundance and production showed little response. Primary production showed a much greater increase in response to aerosol inputs than community respiration did, so that the P/R ratio increased from around 0.95 in the ambient waters, where communities were close to metabolic balance, to 3.3 at the highest nutrient inputs, indicative of a high excess production and a potential for substantial net CO2 removal by the community in response to aerosol inputs. These results showed that aerosol inputs are major vectors of nutrient and carbon inputs, which can, during high depositional events, enhance new production in the NE subtropical Atlantic Ocean.

Original languageEnglish (US)
Article numberG04006
JournalJournal of Geophysical Research: Biogeosciences
Volume111
Issue number4
DOIs
StatePublished - Dec 28 2006

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Fingerprint

Dive into the research topics of 'Aerosol inputs enhance new production in the subtropical northeast Atlantic'. Together they form a unique fingerprint.

Cite this