he color of diatoms from space
How can you see diatoms from space if you can't even see them from the beach? Some environments are so favorable for diatom accumulation that extremely high concentrations of diatoms can change the color of the ocean's surface waters. The brownish chloroplasts are the source of color. By noting the color of the ocean, the ocean's productivity can be estimated; the logic being - the more photosynthetic organisms there are, the more tinted the ocean will appear from a distance. It is then a matter of knowing how different tints correspond to particular abundances of organisms. While they're of primary importance, diatoms are not the only photosynthetic organisms in the ocean.

SeaWiFS is a research program that observes the ocean's color from space using satellites. It is important to monitor the ocean's color because this knowledge helps us to anticipate changes in the earth's climate. Photosynthetic organisms such as diatoms play a key role in regulating the earth's atmospheric carbon dioxide and thus the earth's climate. The subject is quite complex. We'll explore this in a future module.