English: Greens and blues colored the waters of Shark Bay, Australia in late February 2020. The Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a true-color image of the reddish lands of Western Australia and Shark Bay on February 28. Shark Bay sits at the western-most point of the continent.

The blue and greens are most likely created by phytoplankton blooming in these waters. These microscopic plant-like organisms grow year-round in this area, but when conditions are right they begin to multiply rapidly, creating large colonies (“blooms”) that are easily seen from space. Such organisms make up the base of the marine food chain, and the areas where phytoplankton bloom are often very rich in fish and other marine life. Shark Bay is certainly very biodiverse. It has been placed on the World Heritage List in part due to its biodiversity.

According to the United Nations Educational, Scientific, and Cultural Organization (UNESCO), “Shark Bay’s sheltered coves and lush seagrass beds are a haven for marine species, including Green Turtle and Loggerhead Turtle (both Endangered, and the property provides one of Australia’s most important nesting areas for this second species). Shark Bay is one of the world’s most significant and secure strongholds for the protection of Dugong, with a population of around 11,000. Increasing numbers of Humpback Whales and Southern Right Whales use Shark Bay as a migratory staging post, and a famous population of Bottlenose Dolphin lives in the Bay. Large numbers of sharks and rays are readily observed, including the Manta Ray which is now considered globally threatened.”

Another notable feature of Shark Bay is the Wooramel Seagrass Bank. Seagrasses are aquatic flowering plants that grow in meadows in near-shore brackish or marine waters in temperate and tropical regions. Large banks of seagrasses are one of the world’s most productive types of aquatic ecosystems. Covering 103,000 hectares, the Wooramel Seagrass Bank is the largest in the world. Given that the waters of Shark Bay tend to be crystal-clear, some of the green colors seen in this image may be from the greens of this underwater seagrass meadow.