Millennial-scale plankton regime shifts in the subtropical North Pacific Ocean

• Autores: Thomas Larsen, Kelton W. McMahon
• Localización: Science, ISSN 0036-8075, Vol. 350, Nº 6267, 2015, págs. 1530-1533
• Idioma: inglés
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• Resumen

  • Climate change is predicted to alter marine phytoplankton communities and affect productivity, biogeochemistry, and the efficacy of the biological pump. We reconstructed high-resolution records of changing plankton community composition in the North Pacific Ocean over the past millennium. Amino acid–specific δ13C records preserved in long-lived deep-sea corals revealed three major plankton regimes corresponding to Northern Hemisphere climate periods. Non–dinitrogen-fixing cyanobacteria dominated during the Medieval Climate Anomaly (950–1250 Common Era) before giving way to a new regime in which eukaryotic microalgae contributed nearly half of all export production during the Little Ice Age (~1400–1850 Common Era). The third regime, unprecedented in the past millennium, began in the industrial era and is characterized by increasing production by dinitrogen-fixing cyanobacteria. This picoplankton community shift may provide a negative feedback to rising atmospheric carbon dioxide concentrations.