Mobile version

Birds track ocean eddies

Image of the Month - September 2009

Filament structures on the 2003-09-24 and 2003-10-6 weeks in the Mozambique Channel, with great frigates locations (colors correspond to different birds; two different kinds of structures can be computed for the same time span). Most of the points can be seen overlaying the darker structures, i.e. the filaments. (Credits IRD)

It seems that satellites are not the only ones tracking eddies from the sky. Great frigates are sea birds, feeding mainly on fishes and squids. When comparing their paths (located by Argos beacons) and ocean dynamics, close correlation can be seen.

Phytoplankton is often found at the border of eddies, and/or on features like the filaments, where  vertical mixing is occuring. So animals feeding on this plankton are located around the same areas, and so on, up to the predators, big fishes like tuna, or sea birds like great frigates. Great frigates fly over the edges of filaments more than two thirds of the time, even if such structures do not spread over more than 30% of the ocean. However, the fact that birds, living outside the waters, are able to follow ocean features is a bit more surprising than for marine animals. Atmospheric currents occuring over ocean dynamic features and/or visual or olfactive senses are probably involved.

Classical altimetry has already permitted to spot such correlations. With new techniques such as filament computations, that enable to exploit altimetry data at a higher resolution, a more accurate view is possible.

See also:

References

  • Tew Kai, E., V. Rossi, J. Sudre, H. Weimerskirch, C. Lopez, E. Hernandez-Garcia, F. Marsaca, V. Garçon, 2009: Top marine predators track Lagrangian coherent structures, Proceedings of the National Academy of Science, vol. 106, n° 20, pp. 8245-8250
EnglishFrançaisEspañol
Rss feedsContactSitemapPartnersFAQGlossaryLexiconMobile
You must enable cookies in your browser preferences to save the modifications
You are using an older version of Internet Explorer, please update to take full advantage of Aviso+ features

Customize the home page

View all widgets
Reduce display
Public profile
User profile

Select/Deselect widgets

Discover AVISO+

Customizable home, reading tools, products search guide, etc.. Discover step by step the features of the new site AVISO+.

Customizable homepage

The new home page is composed of blocks called "widgets".

Rearrange the blocks with a "Click & Drop".

Hide a widget with the cross at the top right. Reset or add a widget with the "wrench" icon. The "User" and "Public" profiles offer a predefined organization.

All the modifications are automatically saved as cookies on your machine so as to enable you to have your own specific AVISO+.

Reading tools

Ease your reading by choosing the page background colour (black/white) and/or by modifying the font size.

Browsing menu and breadcrum trail

To ease your browsing through AVISO+, you can use at any time the main banner items with the interactive submenus or use the browsing menu on the left side of the screen (it is open by default). For more readiness of the page contents, you can fold and unfold the browsing menu by clicking on the tab. At any time you can know where you are thanks to the browsing menu or the breadcrum at the top of the page.

Products search guide

The first submenu of the "Data" banner item leads you to a new search form enabling you to find quickier the product that suits your needs. The list of results is updated according to your selection criteria.

AVISO+ Multimedia

The first submenu of the "Multimedia" banner item leads you to AVISO+ collections of images and videos linked to altimetry and its applications. Have a nice visit!