Chatham Island, New Zealand

The waters around New Zealand's Chatham Islands teem with life. The highly productive waters support massive phytoplankton blooms that sustain valuable stocks of fish. This image, taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite on December 5, 2010, shows the large annual spring-time bloom. The ocean is productive in this region because the topography of the ocean floor brings two currents together around the Chatham Islands. The islands sit on the Chatham Rise, an underwater plateau that stretches from New Zealand's South Island east to just beyond the Chatham Islands. The water north and south of the plateau is very deep. Cold, nutrient-rich, but iron-poor water from the Antarctic flows south of the Chatham Rise. To the north is mostly warm, nutrient-poor, but iron-rich water from the subtropics.