December 26, 2009--Dark green mangrove forests surround the Ba River Delta (lower right) on Viti Levu, Fiji's main island, in a true-color image captured December 18 by NASA's Earth-Observer 1 satellite.
Mangroves help protect and nurture the vast but vulnerable coral reefs nearby, seen as pale blue structures. Rooted in shallow seafloors, the tangled trees often shelter young fish until they're hardy enough for reef life. The roots also trap water-clouding river sediments, which would otherwise deprive reefs of needed sunlight, as well as agricultural runoff, which could encourage harmful algae blooms.
In turn, the reefs slow waves as they speed toward the shore, protecting the mangroves' roots from excessive turbulence.