Tehuantepec eddies: a multi-sensor's view on biology

Image of the month - August 2006

Sea Level Anomalies (top), Sea Surface Temperature (middle) and Chlorophyll content (bottom) for the beginning of February 2003. Upwelling plumes of low SLA and SST and high Chlorophyll emanating from the Gulfs of Tehuantepec (UT) and Papagayo (UP), and eddy (E) features associated with the Gulfs of Tehuantepec (T) and Papagayo (P) are labeled. Three warm, anticyclonic eddies are seen propagating westward, carrying high Chlorophyll water originating from the upwelling at Tehuantepec. (Credits Noaa).

Oceans are naturally complex. This creates a variety of habitats that marine organisms exploit throughout their life. Marine populations tend to aggregate for reproduction, feeding, protection, and migration. Their ability to perform these functions is dependent not only on cues from other organisms, but on features of their physical environment. Locations where organisms tend to concentrate regularly, or where there is high biological activity, are termed "biological hot spots". Because these areas feature high concentrations of organisms, including many species that are commercially exploited, they are often targeted for resource harvesting. Thus, biological hot spots must be an important facet of resource management and conservation efforts, including determining how to implement marine protected areas, refugia, and fishery closures

In June, we talked about the Tehuantepec eddies, as seen by altimetry over the years, and mentionned that these eddies can carry with them biological material far from the shores. Indeed, this region is one among those biological hot spots. It is a highly productive tropical ecosystem, which supports an industrial tuna fishery and other top predators, and is also the stage of the tuna-dolphin conservation issue.

See also


  • Palacios, D.M., S.J. Bograd, D.G. Foley, F.B. Schwing, Oceanographic characteristics of biological hot spots in the North Pacific: A remote sensing perspective, Deep-Sea Research, 2006, doi:10.1016/j.dsr2.2006.03.004