Mangrove forests are extraordinarily diverse coastal communities anchored by salt-tolerant plants along certain tropical seacoasts. Their distinctive aerial roots help to trap sediment, prevent shoreline erosion, and provide habitat for a variety of sea life. Their unique mode of viviparous reproduction (producing seeds that germinate before becoming detached from the parent plant) allows for the rapid dissemination of viable young plants. Mangrove swamps or forests are among the most productive wetlands on the planet. They are also under intense pressure from development, population spread and pollution. The mangroves of Bhitarkanika National Park, in the Kendrapara district of Orissa, India (located at approximately 20