Hundreds of dead dolphins washed up Friday along the shore of a popular tourist destination on Zanzibar's northern coast, and scientists ruled out poisoning. The bottleneck dolphins, which live in deep offshore waters, had empty stomachs, meaning that they could have been disoriented and were swimming for some time to reorient themselves. They did not starve to death and were not poisoned. In the United States, experts were investigating the possibility that sonar from U.S. submarines could have been responsible for a similar incident in Marathon, Florida, where 68 deep-water dolphins stranded themselves in March 2005. A U.S. Navy task force patrols the East Africa coast as part of counterterrorism operations.