Jewel-toned colors swirling in deep blue waters marked a large phytoplankton bloom off the coast of Tunisia in early June, 2014. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured this true-color image on June 5 as it passed over the region.
The swirls are primarily in the Gulf of Gabes. The Gulf of Gabes is a very shallow body of water off the coast of Tunisia which sits over the continental shelf of the African Plate. The depth of the Gulf is less than 200 meters, and the sediment-covered bottom is disturbed by large tides – the difference between low and high tide can be over 2 meters (6.6 feet).
This churning tide also mixes nutrients into the water, frequently making conditions right for large blooms of the microscopic organisms (phytoplankton) that live in the waters year round. When blooms are large, they can easily be viewed from space.