Saharan dust deposition may affect phytoplankton growth in the Mediterranean sea at ecological time scales

PLoS One. 2014 Oct 21;9(10):e110762. doi: 10.1371/journal.pone.0110762. eCollection 2014.

Abstract

The surface waters of the Mediterranean Sea are extremely poor in the nutrients necessary for plankton growth. At the same time, the Mediterranean Sea borders with the largest and most active desert areas in the world and the atmosphere over the basin is subject to frequent injections of mineral dust particles. We describe statistical correlations between dust deposition over the Mediterranean Sea and surface chlorophyll concentrations at ecological time scales. Aerosol deposition of Saharan origin may explain 1 to 10% (average 5%) of seasonally detrended chlorophyll variability in the low nutrient-low chlorophyll Mediterranean. Most of the statistically significant correlations are positive with main effects in spring over the Eastern and Central Mediterranean, conforming to a view of dust events fueling needed nutrients to the planktonic community. Some areas show negative effects of dust deposition on chlorophyll, coinciding with regions under a large influence of aerosols from European origin. The influence of dust deposition on chlorophyll dynamics may become larger in future scenarios of increased aridity and shallowing of the mixed layer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Africa, Northern
  • Chlorophyll / metabolism*
  • Desert Climate
  • Dust*
  • Marine Biology*
  • Mediterranean Sea
  • Phytoplankton / growth & development*

Substances

  • Dust
  • Chlorophyll

Grant support

The work was supported by the following: JAE-Predoc fellowship from the Spanish Scientific Research Council (CSIC), RG; Aerosol deposition and ocean plankton dynamics (CTM2011-23458), Spanish Ministry of Science and Innovation project, http://www.idi.mineco.gob.es/, RG and FP; Estructura de la materia orgánica en el océano costero: implicaciones biogeoquímicas y ecológicas (CTM2009-09352), Spanish Ministry of Science and Innovation project, http://www.idi.mineco.gob.es/, FP; Grup d'Oceanografia Mediterrània (2009/SGR/588), Generalitat de Catalunya project, http://www10.gencat.cat/agaur_web/AppJava/catala/index.jsp, RG and FP; La ricerca italiana per il mare, Italian Ministry of Education, University and Research, http://www.ritmare.it/, GV; Acoplamiento on-line de un modulo completo de aerosoles multicomponente al modelo atmosferico global regional NMMB (CGL2010-19652), Spanish Ministry of Science and Innovation project, http://www.idi.mineco.gob.es/, SB and JMB; Supercomputación and e-ciencia project (CSD2007-0050) from the Consolider-Ingenio 2010 program of the Spanish Ministry of Economy and Competitivity, http://www.idi.mineco.gob.es/, SB and JMB; and Severo Ochoa program (SEV-2011-00067) from Spanish Ministry of Economy and Competitivity, http://www.idi.mineco.gob.es/, SB and JMB. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.