Articles | Volume 6, issue 5
Biogeosciences, 6, 835–848, 2009
Biogeosciences, 6, 835–848, 2009

  15 May 2009

15 May 2009

Rapid reorganization in ocean biogeochemistry off Peru towards the end of the Little Ice Age

D. Gutiérrez1, A. Sifeddine2,11, D. B. Field3,*, L. Ortlieb2, G. Vargas4, F. P. Chávez3, F. Velazco1, V. Ferreira5, P. Tapia6, R. Salvatteci1,5, H. Boucher2, M. C. Morales7, J. Valdés8, J.-L. Reyss9, A. Campusano1, M. Boussafir10, M. Mandeng-Yogo2, M. García2, and T. Baumgartner5 D. Gutiérrez et al.
  • 1Instituto del Mar del Perú (IMARPE), Dirección de Investigaciones Oceanográficas, Av. Gamarra y Gral. Valle, s/n, Chucuito, Callao, Peru
  • 2Institut de Recherche pour le Développement (IRD), UR Paléotropique (presently: LOCEAN, UMR 7159 CNRS-IRD-Univ. P. & M. Curie-MNHN), 32 Avenue Henri Varagnat, 93143 Bondy cedex, France
  • 3Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA
  • 4Departamento de Geología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Plaza Ercilla 803, Santiago, Chile
  • 5Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Km. 107 Carretera Tijuana – Ensenada, Ensenada, 22860, Mexico
  • 6Biological Sciences Department, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, Lima 31, Peru
  • 7Laboratorio de Paleontología, Instituto Geológico Minero Metalúrgico, Av. Canadá 1470, Lima 41, Peru
  • 8Facultad de Recursos del Mar, Universidad de Antofagasta, Casilla 170, Antofagasta, Chile
  • 9Laboratoire des Sciences de Climat et de l'Environnement, UMR CEA – CNRS-Univ. Versailles-Saint Quentin en Yveline, 91 198 Gif-Sur-Yvette, France
  • 10Institut des Sciences de la Terre (ISTO), Université d'Orléans, 45067 Orléans, France
  • 11Departamento de Geoquimica, Universidade Federal Fluminense, Niteroi-RJ, Brasil
  • *now at: Hawaii Pacific University, College of Natural Sciences, 45-045 Kamehameha Highway, Kaneohe, HI, 96744-5297, USA

Abstract. Climate and ocean ecosystem variability has been well recognized during the twentieth century but it is unclear if modern ocean biogeochemistry is susceptible to the large, abrupt shifts that characterized the Late Quaternary. Time series from marine sediments off Peru show an abrupt centennial-scale biogeochemical regime shift in the early nineteenth century, of much greater magnitude and duration than present day multi-decadal variability. A rapid expansion of the subsurface nutrient-rich, oxygen-depleted waters resulted in the present-day higher biological productivity, including pelagic fish. The shift was likely driven by a northward migration of the Intertropical Convergence Zone and the South Pacific Subtropical High to their present day locations, coupled with a strengthening of Walker circulation, towards the end of the Little Ice Age. These findings reveal the potential for large reorganizations in tropical Pacific climate with immediate effects on ocean biogeochemical cycling and ecosystem structure.

Final-revised paper