of Mumbai and Thane are located. It is separated from the Konkan mainland by the Vasai creek and the Ulhas river. Mumbai was originally a distinct island from Thane, but reclamation of land has long since merged the islands. Powai Lake, Tulsi Lake and Vihar Lake are the largest lakes on the island. Mumbai Port Mumbai Port (MbPT) lies midway () on the western shore of Mumbai Harbour. The port was the pre-eminent commercial port of India in the nineteenth and twentieth centuries. It is known as the gateway to India, and has been a primary factor in the emergence of Mumbai as the commercial capital of India. Ecology Mangrove swamps line much of the northwestern and eastern shores of the harbour, and provide a rich habitat for wildlife, including thousands of migrating birds such as flamingoes. Pollution Due to immense population pressures from the Mumbai metropolitan region and the extremely busy maritime trade, the Harbour is considered to be heavily polluted. This includes reports of heavy metals flux found in the creeks adjacent to the harbour with the harbour acting as a sink for most of the pollutants. See also Sunk Rock Lighthouse References External links Mumbai Port Trust Estuaries of Mumbai Ports and harbours of Maharashtra Transport in Mumbai