Digital.CSIC > Ciencia y Tecnologías Físicas > Instituto de Física Interdisciplinar y Sistemas Complejos (IFISC) > (IFISC) Artículos >




Open Access item Top marine predators track Lagrangian coherent structures

Authors:Tew Kai, Emilie
Rossi, Vincent
Sudre, Joel
Weimerskirch, Henri
López, Cristóbal
Hernández-García, Emilio
Marsac, Francisc
Garçon, V.
Keywords:Finite-size Lyapunov exponents, Frigatebird, Mozambique Channel, Submesoscale
Issue Date:19-May-2009
Publisher:National Academy of Sciences (U.S.)
Citation:Proceedings of the National Academy of Sciences of the USA (PNAS) 106(20): 8245-8250 (2009)
Abstract:Meso- and submesoscales (fronts, eddies, filaments) in surface ocean flow have a crucial influence on marine ecosystems. Their dynamics partly control the foraging behaviour and the displacement of marine top predators (tuna, birds, turtles, and cetaceans). In this work we focus on the role of submesoscale structures in the Mozambique Channel on the distribution of a marine predator, the Great Frigatebird. Using a newly developed dynamical concept, namely the Finite-Size Lyapunov Exponent (FSLE), we have identified Lagrangian coherent structures (LCSs) present in the surface flow in the Channel over a 2-month observation period (August and September 2003). By comparing seabird satellite positions with LCSs locations, we demonstrate that frigatebirds track precisely these structures in the Mozambique Channel, providing the first evidence that a top predator is able to track these FSLE ridges to locate food patches. After comparing bird positions during long and short trips, and different parts of these trips, we propose several hypotheses to understand how frigatebirds can follow these LCSs. The birds might use visual and/or olfactory cues and/or atmospheric current changes over the structures to move along these biological corridors. The birds being often associated to tuna schools around foraging areas, a thorough comprehension of their foraging behaviour and movement during the breeding season is crucial not only to seabird ecology but also to an appropriate ecosystemic approach of fisheries in the channel.
Description:6 pages, 4 figures, 1 table.-- PDF ArXiv pre-print: http://arxiv.org/abs/0904.1959
Publisher version (URL):http://dx.doi.org/10.1073/pnas.0811034106
Appears in Collections:(IFISC) Artículos

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.