MISCELLANEOUS ECOSYSTEMS > LAGOONS
Atoll lagoons occur mostly in the tropical and subtropical latitudes where coral reefs are common. The formation of such a lagoon can take tens of thousands of years and begins when an island subsides (sinks) into the ocean, usually due to volcanic or seismic action. The island may vanish from sight, but the coral reefs which ring it continue to grow, eventually forming a barrier between the open sea and creating a sheltered interior which becomes the lagoon. The lagoons above are located around the islands of Bora Bora.
An atoll lagoon may act as breeding ground for all kinds of marine life. Because lagoons are relatively small spaces, large marine animals such as whales and large sharks may not enter them. However, lagoons can be a safe space for juveniles of these species as well as a variety of sea birds, sea turtles, and invertebrates.
Examples of atoll lagoons in American territory include the Johnston Atoll National Wildlife Refuge, Midway Atoll National Wildlife Refuge, and the Palmyra Atoll.
Atoll lagoons occur mostly in the tropical and subtropical latitudes where coral reefs are common. The formation of such a lagoon can take tens of thousands of years and begins when an island subsides (sinks) into the ocean, usually due to volcanic or seismic action. The island may vanish from sight, but the coral reefs which ring it continue to grow, eventually forming a barrier between the open sea and creating a sheltered interior which becomes the lagoon. The lagoons above are located around the islands of Bora Bora.
An atoll lagoon may act as breeding ground for all kinds of marine life. Because lagoons are relatively small spaces, large marine animals such as whales and large sharks may not enter them. However, lagoons can be a safe space for juveniles of these species as well as a variety of sea birds, sea turtles, and invertebrates.
Examples of atoll lagoons in American territory include the Johnston Atoll National Wildlife Refuge, Midway Atoll National Wildlife Refuge, and the Palmyra Atoll.
Endangered Coral, Endangered Lagoons:
Due to climate change, atoll lagoons are disappearing worldwide. Often the corals that create them are being wiped out due to increase water temperatures and coral bleaching. Bleaching is when the water becomes so warm that coral polyps expels algae which lives inside their tissues. This algae is essential to the health of the coral, providing up to 90% of its energy. Once the algae is expelled, the entire coral reef can die and the lagoon would eventually be destroyed by the wave action of the sea.