Dust Over the Arabian Sea
Dust blowing out of India, Pakistan, and Afghanistan mingled over the Arabian Sea on April 9, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite took this picture the same day.
In this image, a beige plume of dust, shown near the left edge of the picture, pushes southward from Afghanistan, crossing over Pakistan toward the ocean. To the east, another dust plume over the border between India and Pakistan also heads toward the water. Two tendrils of dust merge over the water, just south of the coast.
Also visible along the coastline are dark green patches in the water, indicating the presence of phytoplankton. These microscopic plants that form the base of the food web are likely being "fertilized" by the iron-rich desert dust that is blowing into the water. Unlike terrestrial plants which get their nutrients from the soil, aquatic plants rely on "Aeolian" or wind-blown particles.
Iron, as well as nitrate and phosphate, from the dust are consumed by phytoplankton and bacteria, which are in turn consumed by small marine animals - also called zooplankton - which are eaten by fish, whales, birds, and other organisms.