National Geographic : 2014 Sep
116 national geographic • September 2014 116 national geographic • September 2014 Kennedy Warne wrote about two Mozambique Channel atolls for the April issue. Brian Skerry photographed bluefin tuna for the March issue. 0mi 100 0km 100 Protected Area 12-nautical-mile fishing exclusion zone Land above sea level BATHYMETRY GIVEN IN FEET 19,849 2,215 16,735 14,753 NGM MAPS Malden Island Vostok Island Caroline Island (Millennium Island) Flint Island Starbuck Island 11sqmi 0.1 sq mi 1.5 sq mi 1sqmi 8sqmi 155°W 150°W 5°S 10°S SOUTH PACIFIC OCEAN KIRIBATI AREA ENLARGED Line Islands HAWAII (U.S .) AUSTRALIA NORTH AMERICA SOUTH PACIFIC OCEAN NORTH PACIFIC OCEAN EQUATOR highest ever reported from a coral reef. At sev- eral locations divers saw endangered Napoleon wrasses, one of the world’s largest reef fish. Also known as the humphead wrasse because of a pronounced bump on the forehead of mature adults, these fish can grow to more than six feet long—large enough to sometimes have their own escort fish, as sharks and large rays do. The waters around the islands showed the “inverted biomass pyramid” of healthy reefs, in which top predators, as measured by cumulative weight, account for most of the fish—at Malden Island, more than 70 percent. Predator domi- nance had been previously reported at Kingman Reef, in the northern Line Islands, on an ear- lier National Geographic expedition. (See “An Uneasy Eden,” National Geographic, July 2008.) “It’s a seascape of fear,” says photographer Brian Skerry, who was on the expedition. “Everything is either hunting or being hunted.” On one dive at dusk—what Skerry calls the “shark witching hour”—he found himself hemmed in by gray reef sharks. “There must have been 60 of them,” he says. “I was trying to photograph in a three-sided coral head, and one of them would come in really close. Usually a shark will go away, at least temporarily, if you fend it off, but these guys were doing a quick 360-degree turn and coming right back, and be- hind that one were five more, and behind them another ten, and you could see them jockeying for position. In 36 years of diving I’ve had some dicey moments with predators, but I’ve never felt physically hunted, as I was here.” That abundance of predators could easily be lost. Sala reckons it would take just a few The Line Islands were so named because they straddle the Equator, known to sailors as “the line.” Malden Island is largely barren above water but possesses an underwater luxuriance that attracted scientists from National Geographic’s Pristine Seas project.