The Laccadive Sea, also known as the Lakshadweep Sea, is a body of water bordering India (including its Lakshadweep islands), the Maldives, and Sri Lanka. It is located to the southwest of Karnataka, to the west of Kerala and to the south of Tamil Nadu. This warm sea has a stable water temperature through the year and is rich in marine life, the Gulf of Mannar alone hosting about 3,600 species. Mangaluru, Kasaragod, Kannur, Kozhikode, Ponnani, Kochi, Alappuzha, Kollam, Thiruvananthapuram, Tuticorin, Colombo, and Malé are the major cities on the shore of the Laccadive Sea. Kanyakumari, the southernmost tip of peninsular India, also borders this sea. Extent The International Hydrographic Organization defines the limits of the Laccadive Sea as follows: On the West. A line running from Sadashivgad Lt. on West Coast of India () to Corah Divh () and thence down the West side of the Laccadive and Maldive Archipelagos to the most Southerly point of Addu Atoll in the Maldives. On the South. A line running from Dondra Head in Sri Lanka to the most Southerly point of Addu Atoll. On the East. The West coasts of Sri Lanka and India. On the Northeast. Adams Bridge (between India and Sri Lanka). Hydrology Water temperature is rather constant through the year, averaging 26–28 °C in summer and 25 °C in winter. Salinity is 34‰ (parts per thousand) in the center and northern part and up to 35.5‰ in the south. The coasts are sandy but the deeper parts are covered in silt. There are numerous coral reefs in the sea, such as the Lakshadweep islands which are made up of atolls and contain 105 coral species. Fauna and human activities The Gulf of Mannar is known for its pearl banks of Pinctada radiata and Pinctada fucata for at least two thousand years. Pliny the Elder (23–79) praised the pearl fishery of the gulf as the most productive in the world. Although extraction of natural pearls is considered too expensive in most parts of the world, it is still conducted in the gulf. Also collected in large numbers are Shankha mollusks (Xancus pyrum) whose shells are used as a ritual and religious object. Other mollusks of the sea are either too scarce or not popular in Indian society and therefore have no commercial value. Another traditional occupation in the Laccadive Sea is fishing. The annual fish catch is 2,000 to