Phytoplankton bloom in Shark Bay, Western Australia
The vibrant blue colors visible in this image of Shark Bay, Western Australia are caused by phytoplankton blooms. The bay is located in the Western part of Australia, about 800 kilometers (500 miles) North of Perth. Shark Bay is a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage site, containing abundant wildlife â€“ numerous in species as well as individuals. These include over 10,000 dugongs or sea cows (somewhat similar to manatees) as well as dolphins, 26 other threatened mammal species, 230 bird species, over 300 species of fish, and about 150 species of reptiles. Shark Bay is also home to the largest bed of sea grass on the planet, measuring over 4,800 square kilometers (1,800 square miles). Sea grasses are a very important component of marine ecosystems, providing food and shelter to many organisms. Phytoplankton blooms, such as the one seen here, can occur when currents deep beneath the ocean surface reach the coastline and are forced to the surface, carrying minerals such as iron with them. Tiny, microscopic plants called phytoplankton are poised to rapidly exploit this temporary resource, growing very rapidly under such conditions.