Images from the Envisat satellite released by the European Space Agency displayed a 300 x 200-km phytoplankton bloom in the seas off Nova Scotia and Newfoundland in Canada from July 24 to Aug. 13, 2002. Although such blooms are not uncommon, they typically occur in the spring in temperate latitudes, associated with the seasonal upwelling of nutrients. A better understanding of such phenomena The images were taken with the satellite's Medium-Resolution Imaging Spectrometer instrument. The device collects data at 15 wavelengths from the visible to the near-IR, producing a whole-Earth image every three days. Using its 681-nm channel, which corresponds to the peak fluorescence of chlorophyll, the imager can detect phytoplankton concentrations as low as 0.00001 mg/l.