Photosynthesis and Respiration

Photosynthesis takes place all over the world - on land and in the oceans. This image shows the global distribution of photosynthesis, which includes both oceanic phytoplankton and terrestrial vegetation. On the image, dark red, blue, and green indicate the regions of highest photosynthetic activity. What surprises you about this image? Why are some areas lacking photosynthesis? Why are some areas extremely high in photosynthetic activity?