Das Eisen von Schiffswracks zerstört Korallenriffe

Black Reefs–When the Ship Hits the Reef

Posted by Enric Sala of National Geographic September 1, 2011

The first time I dived at the remote Kingman Reef, in 2005, I thought I found paradise. In the middle of the Pacific Ocean, almost 2000 km south of Hawaii, lies a pristine coral reef, covered with colorful corals and a carpet of giant clams with unbelievable electric blues and greens. When I returned in 2007, I thought I had entered the dark land of Mordor.

The healthy corals of the windward side of Kingman Reef, permanently washed by the breaking waves, had died, and the reef shifted into a carpet of dark slime – filamentous algae and microbes. The former crystal clear waters were now murky like a swimming pool after turning off the filtration system. We called it the ‘black reef.’

Pristine vs 'black reefs' on the Line Islands. Left column (top to bottom): Kingman Reef, Millennium Atoll, Malden Island (photos by Enric Sala). Right column (top to bottom): Black reef at Kingman, black reef at Millennium, and anchor chain killing corals at Jarvis Island (photos by Gareth Williams, David Obura and Mark Vermeij).