In a new study published in the journal Conservation Biology, NOAA’s Pacific Reef Assessment and Monitoring Program has compiled shark sighting data from more than 1,607 dives at 46 reefs in the central-western Pacific, which included reefs near the Hawaiian islands and American Samoa as well as extremely isolated reefs nearly devoid of human influence. Though eight species of shark were seen on the dives, the researchers excluded sharks, such as hammerheads, that aren’t dependent on reefs. This left them with five shark species to tally: gray reef sharks, blacktip reef sharks, whitetip reef sharks, Galapagos sharks and tawny nurse sharks.
Study leader Marc Nadon commented on the survey’s results:
“Around each of the heavily populated areas we surveyed — in the main Hawaiian Islands, the Mariana Archipelago, and American Samoa — reef shark numbers were greatly depressed compared to reefs in the same regions that were simply [farther] away from humans,” and went on to say. “We estimate that less than 10 percent of the baseline numbers remain in these areas.”