<p><strong>Fig. 9.17.</strong> Map of global sea surface chlorophyll concentration. Chlorophyll concentration (mg/m<sup>3</sup>) is an indication of the density of photosynthetic organisms, such as phytoplankton, in the epipelagic zone.</p>

Fig. 9.17. Map of global sea surface chlorophyll concentration. Chlorophyll concentration (mg/m3) is an indication of the density of photosynthetic organisms, such as phytoplankton, in the epipelagic zone.

Image courtesy of National Aeronautics and Space Administration (NASA)