The Lakshadweep islands lie on the northernmost edge of the Laccadives-Chagos ridge. It is believed that this ridge is a continuation of the Arravali hills in India, and the islands are remnants of the submerged mountain cliffs. There are three major reefs in the Lakshadweep islands. The islands are made up of coral sand and boulders. During high tide, there is water exchange between the islands’ lagoon and the sea over the reef. The coral fauna of Lakshadweep is home to more than 100 species. Crabs, sea cucumbers, turtles and varieties of fish are found here. People flock here to watch as well as study these coral formations. Tourists come here to go snorkelling and Scuba diving. Some coral reef sections in Lakshadweep are classified as endangered. Global warming, poor maintenance and carelessness of diving tourists cause harm to the reefs. Improper sewage disposal also adds to the menace.