for National Geographic News
This story is one of a series looking at National Geographic Crittercam research. Crittercam is a research instrument worn by wild animals and equipped with a video camera and other information-gathering equipment. (Get the basics on underwater and terrestrial Crittercams.)
Only about 1,300 monk seals are believed to be surviving in the relatively remote waters of the Northwestern Hawaiian islands. To find out more about what is causing the precipitous decline in their numbers, researchers are using National Geographic's Crittercam technologycameras attached to seals to find out how these large marine mammals find their food.
Before he began researching Hawaiian monk seals, Frank Parrish never thought much of the odd creatures. To the fishery biologist, who grew up in Hawaii, the seals were little more than lazy brown logs languishing on the beach.
That's before he saw footage of them underwater shot with National Geographic's Crittercam.
"Riding on the back of the seals, [via Crittercam's perspective], my whole perspective of them changed," said Parrish, who works for the National Oceanic and Atmospheric Administration (NOAA), a U.S. government agency. "They were no longer just logs lounging in the sun. They became guides taking us through the submarine landscape. It was fantastic."
The Crittercam study immediately offered new insights into the foraging behavior of the highly endangered monk seals. Researchers had long focused on the lush coral reefswith plenty of fish around themas the natural feeding ground for the seals. But Crittercam footage showed the seals do not stay on the reef; Instead they venture far off shore for food.
"They go out onto these deep slopes, which appear barren with pretty much just sand and loose rock, and that's where they make their living," Parrish said. "This [knowledge] has changed our mind-set. Now that we know the seals are feeding outside the atolls, we have to take that habitat into consideration in the protection of the seal."
A string of tiny atolls and islands, the Northwestern Hawaiian Islands provide a refuge for 30 species of seabirds, endangered green sea turtles, and the most primitive living pinniped: the Hawaiian monk seal. Pinnipeds are aquatic mammals with all flour limbs modified into flippers.
These seals are dark, two-tone creatures with big eyes and rounded heads that look a little bit like hoods, hence the name "monk seals." An adult can live up to 30 years and grow upwards of 600 pounds (270 kilograms).