A comprehensive census of Pacific reef shark populations has found that shark abundance has plummeted by roughly 90 percent in waters located near islands inhabited by humans. Using underwater surveys
conducted by divers across 46 U.S. Pacific islands and atolls, researchers found that shark numbers near human populations were consistently depressed, regardless of location or ocean conditions, compared with pristine reef areas located farther away from humans. In fact, the researchers estimated that shark populations are less than 10 percent of historically peak numbers in these areas, said Marc Nadon, a University of Hawaii scientist and lead author of the study, published in Conservation Biology. “In short, people and sharks don’t mix,” he said. Researchers say the data helps quantify how human activities, including overfishing and the controversial practice of shark-finning, are decimating shark numbers.