On the track of tiny larvae, a new model elucidates connections in marine ecology

The work is reported by Heather M. Galindo and Stephen R. Palumbi of Stanford University, and Donald B. Olson of the University of Miami, and appears in the August 22nd issue of Current Biology, published by Cell Press.

Effective marine management and conservation planning require a better understanding of the movement of young marine animals, including small larvae, in part because such movements facilitate normal biological connections among geographically separate populations. Although tiny larvae are impossible to follow directly, advances in modeling ocean currents have made it possible to predict larval movements. However, until now it has remained difficult to test these movement predictions in the field by comparing the model to data from population genetic studies.

The new work enables scientists to field-test such predictions and thereby hone our understanding of how marine larvae disperse in the environment and influence the structure of adult populations. In their study, the researchers coupled two types of models: One model predicts the movements of “virtual” coral larvae in the Caribbean Sea based on ocean currents, while the second model gives the virtual larvae a genetic tag. The researchers then tested this new approach by comparing the new model's predictions to empirical genetic data for threatened staghorn corals. This test showed that combining the oceanographic and genetic models allowed the researchers to successfully predict genetic patterns on a regional scale. This breakthrough approach to integrating genetic and oceanographic models helps predict genetic links among several locations and is an important new tool for the management and ecological study of marine protected areas.