Coccolithophores in the Bering Sea
The Bering Straitâ€”the stretch of water between Siberia and Alaskaâ€”features some of the world's most productive ocean waters. This Sea-viewing Wide Field-of-view Sensor (SeaWiFS) image shows phytoplankton covering vast stretches of water. Phytoplankoton are microscopic plants that form the base of the marine food chain.
The green water on the left features a high concentration of phytoplankton. On the right, off the west coast of Alaska, a bloom of a specific type of phytoplankton, coccolithophores, appears bright blue-green. Coccolithophores have white calcium-rich shells that reflect sunlight and brighten the water. The coccolithophore shellsâ€”coccolithsâ€”have persisted in the Bering Sea since 1997, but appear to be fading.