Palk Strait

Topic: India and her Neighbours · NCERT: Class 7, Ch 2 "India and Her Neighbours"; Class 11, Ch 1 "India - Location"

Meaning

The Palk Strait is a narrow, shallow strip of sea between Tamil Nadu in India and northern Sri Lanka. It joins the Bay of Bengal to Palk Bay. At their closest point, India and Sri Lanka are only about 32 km apart across this strait (NCERT Class 7).

It matters because India and Sri Lanka share a sea boundary here. The tiny islet of Katchatheevu lies in it, Tamil Nadu fishermen depend on its waters, and the stalled Sethusamudram ship channel was planned to pass through it.

Explanation

What a strait is, and how the Palk Strait fits

• A strait is a narrow strip of sea that joins two larger seas.

• The Palk Strait joins the Bay of Bengal in the north to Palk Bay in the south.

• Why the sea here is so shallow:

• Sri Lanka sits on the same continental shelf as India. A continental shelf is the shallow, gently sloping sea floor at the edge of a continent.
• So the sea between the two countries is shallow. It is not deep ocean.

• Big ships cannot sail through it easily. Small boats can cross it easily.

• Result: the strait is both a link and a barrier. People, culture and refugees cross it easily. Large ships have to sail all the way around Sri Lanka.

The sea between India and Sri Lanka: its parts, from north to south

• Bay of Bengal → Palk Strait → Palk Bay → Adam's Bridge → Gulf of Mannar.
• Palk Bay: a shallow stretch of water south of the strait. Adam's Bridge closes it off on its south side.
• Adam's Bridge (Rama Setu):
• A chain of limestone shoals, about 48 km long. Shoals are shallow sandbanks and rocks lying just under the sea surface.
• It runs from Pamban (Rameswaram) Island to Mannar Island, which is off the northwest coast of Sri Lanka. Britannica gives its length as about 30 miles [5].

• It separates Palk Bay from the Gulf of Mannar.

• Gulf of Mannar: a shallow inlet of the sea south of Adam's Bridge. It has coral reefs, seagrass and dugongs.

• NCERT Class 11 names two water bodies that separate India and Sri Lanka: the Gulf of Mannar and the Palk Strait.

The Palk Strait as a boundary

• Katchatheevu is a small uninhabited islet in the Palk Strait.
• 1974 agreement:
• Signed at Colombo on 26 June 1974 and at New Delhi on 28 June 1974.
• It fixed the boundary in the historic waters of the Palk Strait [2].
• Under this agreement, Katchatheevu falls on the Sri Lankan side.

• Indian fishermen and pilgrims could still visit Katchatheevu as before, without visas or travel documents [2].

• 1976 agreements (south and north of the strait):

• The agreement of 23 March 1976 fixed the boundary in the Gulf of Mannar and the Bay of Bengal [2].
• A Supplementary Agreement of 22 November 1976 extended the Gulf of Mannar boundary [2].
• NCERT notes that the 1976 agreement limited Indian fishing in Sri Lankan waters.

Sethusamudram Ship Channel Project: the plan to deepen the strait

• Aim: to dredge (dig out) the shallow sea floor and make a ship channel through Palk Bay, Palk Strait and Adam's Bridge.
• Ships would then not need to sail around Sri Lanka.

• The Government of India approved the project in 2005 [5].

• Why it stopped:

• On 14 September 2007, a Supreme Court interim order stopped dredging only at Adam's Bridge / Ram Sethu [4].
• Because of long court cases, all dredging in Palk Bay and Palk Strait also stopped in July 2009 [4].
• By then, only about 9.52 million cubic metres had been dredged. This was 19.81% of the planned 48.05 million cubic metres [4].

• Objections came from three sides: the religious importance of Rama Setu, possible loss of thorium deposits, and fear of greater tsunami risk [5].

• New plan: in March 2018, the government told the court it would look for a different route that does not damage Adam's Bridge [4].

Where it occurs

• India side: the coast of Tamil Nadu. Pamban (Rameswaram) Island lies at the southern end of the Palk Bay system.
• Sri Lanka side: northern Sri Lanka, the Tamil-majority north. Mannar Island is off its northwest coast.
• Seas it joins: the Bay of Bengal (north) and Palk Bay (south).
• Inside the strait: the islet of Katchatheevu, which belongs to Sri Lanka under the 1974 agreement [2].
• Further south: Adam's Bridge, and beyond it the Gulf of Mannar Biosphere Reserve. Its 21 islands lie off the Ramanathapuram and Thoothukudi (Tuticorin) districts [3].
• Human crossings:
• In the 3rd century BCE, Ashoka sent Mahendra and Sanghamitra to Sri Lanka, and they took Buddhism there.
• During the civil war (mid-1980s to around 2010), many Tamils crossed this narrow sea as refugees to Tamil Nadu.

Don't confuse with

• Palk Bay: the Palk Strait is the narrow link that joins the Bay of Bengal to Palk Bay. Palk Bay is the shallow water body south of it, closed off by Adam's Bridge.
• Gulf of Mannar: it lies south of Adam's Bridge, not north of it. It is a gulf (a large sea area partly closed in by land), famous for coral reefs and dugongs. The Palk Strait is a strait (a narrow joining channel).
• Adam's Bridge (Rama Setu): this is not water but a chain of limestone shoals, from Pamban Island to Mannar Island. It separates Palk Bay from the Gulf of Mannar.
• Eight Degree Channel: this separates Minicoy from the Maldives. India's sea gap with Sri Lanka is the Palk Strait, not a "degree channel".

Prelims Hooks

• Palk Strait joins the Bay of Bengal to Palk Bay. It lies between Tamil Nadu and northern Sri Lanka.
• Order from north to south: Bay of Bengal → Palk Strait → Palk Bay → Adam's Bridge → Gulf of Mannar.
• India and Sri Lanka are only about 32 km apart at the nearest point, across the Palk Strait (NCERT Class 7).
• Katchatheevu lies in the Palk Strait, not the Gulf of Mannar. It went to Sri Lanka under the 1974 agreement. The 1976 agreement covered the Gulf of Mannar and the Bay of Bengal [2].
• Adam's Bridge runs from Pamban (Rameswaram) Island to Mannar Island and is about 48 km long.
• Sethusamudram: approved in 2005 [5]. Dredging at Adam's Bridge stopped by a Supreme Court order on 14 September 2007, and all dredging in Palk Bay and Palk Strait stopped in July 2009 [4].

Mains Points

• Livelihood versus sovereignty in the Palk Bay region (GS-I/II):
• The sea is narrow and shallow, so boats cross the boundary line easily.
• Tamil Nadu trawlers (fishing boats that drag large nets) fish in Sri Lankan waters. Sri Lanka arrests the fishers, and Tamil Nadu then asks for Katchatheevu to be taken back (verify current).

• Possible solutions: deep-sea fishing boats, ending bottom trawling (dragging nets along the sea floor), and joint working groups.

• Development versus environment and faith (GS-III):

• A channel through Palk Bay, Palk Strait and Adam's Bridge would make shipping routes shorter, because ships would not have to go around Sri Lanka.
• But it threatens the coral reefs and dugong habitat of the Gulf of Mannar, and it touches the religious meaning of Rama Setu. Fears about thorium and tsunami risk were also raised [5].

• That is why, in March 2018, the government said it would look for a different route [4].

• Geography shapes history and migration (GS-I):

• The short, shallow crossing has carried Buddhism (3rd century BCE), the Indian epics, and Tamil refugees during Sri Lanka's civil war.

Related concepts

• Sri Lanka
• Gulf of Mannar
• Adam's Bridge
• Katchatheevu
• Maldives

Read more

• Sri Lanka and the Maldives: the island neighbours