Adam's Bridge Marine National Park

Lore & Background

The park was created following a recommendation in an Integrated Strategic Environmental Assessment of Northern Province, produced by the government with assistance from the United Nations Development Programme and United Nations Environment Programme, published in October 2014. In May 2015, the government announced that a part of Adam's Bridge, along with Chundikkulam, Delft and Madhu Road, would be designated national parks. Adam's Bridge became a national park on 22 June 2015 with an area of 18,990 ha.

Reader's Guide

Adam's Bridge Marine National Park holds significance as a protected area for migratory birds, which follow the Pamban Island-Adam's Bridge-Mannar Island route when flying to or from Sri Lanka. The sand dunes of Adam's Bridge serve as breeding grounds for birds such as the brown noddy. The shallow waters support numerous varieties of fish and sea grasses, and marine life includes dolphin, dugong, and turtle. The park's creation reflects environmental planning efforts in Sri Lanka's Northern Province. The Indian section of Adam's Bridge is part of the Gulf of Mannar Marine National Park, highlighting the transboundary ecological importance of the bridge. The park's establishment in 2015 added to Sri Lanka's network of national parks, contributing to the conservation of coastal and marine biodiversity in the region.

Did You Know?

• Many migratory birds follow the Pamban Island-Adam's Bridge-Mannar Island route to and from Sri Lanka.
• The sand dunes of Adam's Bridge are used as breeding grounds by birds such as the brown noddy.
• Sea life found around Adam's Bridge includes dolphin, dugong, and turtle.

Geological Formation and Emergence

Stretching forty-eight kilometres between Pamban Island on Tamil Nadu's southeastern shore and Mannar Island off Sri Lanka's northwestern coast, this chain of natural limestone shoals separates the Gulf of Mannar to the southwest from the Palk Strait to the northeast. Geological records indicate that during the Last Glacial Period, spanning roughly 115,000 to 11,700 years before present, ocean levels sank as much as 120 metres below today's mark. Because the Palk Strait reaches a maximum depth of only 35 metres, the entire waterway would have been exposed as dry land, physically joining the Indian subcontinent to Sri Lanka. As Holocene seas rose, the strait became submerged by approximately 7,000 years ago, swallowing the region that now forms the bridge. From around 5,000 years ago onward, regional sea-level declines allowed the shoal islands to re-emerge. The structure itself is composed of parallel ledges of sandstone and conglomerate—firm at the surface but growing coarser and softer toward sandy sub-beds. ISRO's Space Applications Centre identified 103 small patch reefs within the formation, while one study tentatively attributed the raised reef to local tectonic uplift rather than global eustatic change. The absence of thorough fieldwork continues to leave key questions about origin unresolved.

Names Rooted in Faith and Geography

The structure has carried different names across cultures and centuries, each reflecting a distinct spiritual or geographical lens. The earliest known reference appears in Ibn Khordadbeh's Kitāb al-Masālik wa-l-Mamālik, compiled around 850 CE, where the feature is called Set Bandhai, literally meaning Bridge of the Sea. The designation Adam's Bridge likely crystallised around the era of the Persian polymath Al-Biruni, circa 1030. That naming drew on the Islamic tradition placing Adam's Peak—the spot where the first man is said to have descended to earth—on Sri Lankan soil, with the implication that Adam traversed the shallow waterway to reach the Indian subcontinent after his departure from the Garden of Eden. In the Hindu tradition, the ancient Sanskrit epic Ramayana, composed between the eighth century BCE and the third century CE, narrates how the deity Rama constructed a causeway to the island of Lanka in order to liberate his wife Sita from the demon king Ravana. While many scholars locate the epic's original Lanka in present-day Madhya Pradesh, popular Hindu devotion equates it with modern Sri Lanka, and the shoals are reverently called Rama's Setu.

A Persistent Obstacle to Shipping

In the waters surrounding the shoals, depth typically ranges from one to three metres, and in certain stretches the sea floor lies barely a metre below the surface. This extreme shallowness has made the bridge a formidable barrier to maritime traffic threading the Palk Strait. Although commercial exchange between the Indian and Sri Lankan shores dates to at least the first millennium BCE, it was confined to small craft and dinghies. Ocean-going vessels arriving from the west had to round the full circumference of Sri Lanka to reach India's eastern seaboard. In the late eighteenth century, the young British officer James Rennell proposed that a dredged channel through the Ramisseram strait could sustain a navigable passage, but his suggestion was largely ignored, perhaps owing to his junior rank. Sir Arthur Cotton, then an ensign, revisited the idea in 1823 after surveying the Pamban channel. By 1828, Major Sim oversaw the blasting and removal of certain rocks. A more thorough marine survey followed in 1837, conducted by lieutenants Powell, Ethersey, Grieve, and Christopher with draughtsman Felix Jones, and dredging resumed the following year. Yet throughout the nineteenth century, no effort succeeded in keeping the passage workable for anything beyond light-draft vessels.

The Sethusamudram Canal and Political Tension

Long before Indian independence, nine government committees examined possible alignments for a shipping canal across the Palk Strait, and five more were convened after 1947. The overwhelming majority of these bodies recommended land-based routes across Rameswaram Island, and none endorsed cutting directly through the shoals. A 1956 committee went further, urging the Union government to favour land passages on the grounds of multiple practical advantages. The situation shifted dramatically in 2005, when the government approved a multi-million-dollar Sethusamudram Shipping Canal Project designed to open a dredged ship channel near Dhanushkodi. The proposed route would shave more than 400 kilometres—roughly thirty hours of sailing time—off the journey around Sri Lanka, but its current alignment requires dredging directly through the shoals. Opposition mounted quickly from the Bharatiya Janata Party, the All India Anna Dravida Munnetra Kazhagam, the Rashtriya Janata Dal, the Janata Dal (Secular), and various Hindu organisations, all of whom cited the bridge's identification with the Ramayana causeway. These groups proposed an alternate channel routing that would spare the shoals. State and central governments, however, resisted such modifications, with Union Shipping Minister T. R. Baalu defending the original plan.