How far do reef fish larvae travel in marine currents?
October 15, 2012
Most coral reef fishes have a planktonic larval stage. Tiny fish larvae could potentially be dispersed long distances by marine currents. Yet larvae are notoriously difficult to track owing to their small size. Therefore, it is poorly understood whether populations of fish at different sites interact, which is important information for conservationists and managers of marine reserves.
A new reportóby a threesome from STRI: Oscar Puebla, Eldredge Bermingham and Owen McMillanóconsidered how genetic similarity between individuals declines with increasing geographic distance in order to estimate dispersal in five species of coral reef fishes. This approach had never been applied to coral reef fishes before, and for a good reason. It required sampling individuals and monitoring populations along more than 200 kilometers of the Mesoamerican Reef in Belize, an ambitious sampling scheme made possible thanks to support from the Smithsonian Marine Network, STRI and the National Geographic Society. Their results suggest that coral reef fishes disperse over relatively small distances, only a few tens of kilometers on average, considerably less than suggested by previous largescale genetic studies.