Satellites, DNA and dolphins

Satellites, DNA and dolphins ScienceBlog.com

Using DNA samples and images from Earth-orbiting satellites, conservationists from Columbia University, the Wildlife Conservation Society, the American Museum of Natural History, and Fundación AquaMarina, are gathering new insights about the franciscana -- a poorly known coastal dolphin species of eastern South America -- in an effort to understand populations and conserve them.

The study, one of the first to combine molecular data along with range-wide environmental information for a marine species, is helping researchers to understand how seemingly monotonous marine environments actually contain significant habitat differences that are shaping populations of this threatened species, which averages between 5-6 feet in length and around 80-90 pounds in weight. According to findings published in the most recent edition of Molecular Ecology, genetic differences between dolphins from different sites correlate to measurable differences in water temperature, turbidity and chlorophyll levels, a tantalizing indication of how largely hidden oceanographic variables could drive population structure of marine animals.

The authors of the study are: Martin Mendez of Columbia University, the American Museum of Natural History (AMNH), and the Wildlife Conservation Society; Howard Rosenbaum of the Wildlife Conservation Society; Ajit Subramaniam of Lamont Doherty Earth Observatory at Columbia University; Charles Yackulic of Columbia University; and Pablo Bordino of Fundación AquaMarina and the Wildlife Trust Alliance.

"The availability of both genetic and environmental data provided us with a rare opportunity to examine how ecological factors affect population structure in a marine species," said Martin Mendez, the study's lead author. "In this instance, the study subject is possibly the most endangered cetacean in South America, so delineating populations and the factors that create them certainly plays an important role in conservation measures."

As a result of the study, the researchers recommend that the genetically distinct population of franciscanas to the north of Buenos Aires -- probably created in part by oceanographic conditions?should be protected as part of a larger effort to save the species.