Uppu Aru lagoon is a lagoon

Lagoon

A lagoon is a body of shallow sea water or brackish water separated from the sea by some form of barrier. The EU's habitat directive defines lagoons as "expanses of shallow coastal salt water, of varying salinity or water volume, wholly or partially separated from the sea by sand banks or shingle,...

 in Jaffna District

Jaffna District

Jaffna district is one of the 25 administrative districts of Sri Lanka. The district is administered by a District Secretariat headed by a District Secretary appointed by the central government of Sri Lanka. The headquarters is located in Jaffna city. Parts of the district were transferred to...

, northern Sri Lanka

Sri Lanka

Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...

. The lagoon separates the Valikamam

Valigamam

Valikamam is one of the three historic regions of Jaffna peninsula in northern Sri Lanka. The other two regions are Thenmarachchi and Vadamarachchi. Valikamam is sometimes spelt Valikaamam or Valigamam.-Etymology:...

 region from the Thenmarachchi

Thenmarachi

Thenmarachchi is one of the three historic regions of Jaffna peninsula in northern Sri Lanka. The other two regions are Vadamarachchi and Valikamam. Thenmarachchi is sometimes spelt Thenmarachi, Thenmaraachi or Thenmaraadchi...

 region.

The lagoon is linked to Jaffna Lagoon

Jaffna Lagoon

Jaffna lagoon is a large lagoon off Jaffna District and Kilinochchi District, northern Sri Lanka.The lagoon is surrounded by the densely populated Jaffna peninsula containing palmyra palms, coconut plantations, and rice paddies. There are numerous fishing villages and some salt pans.The lagoon has...

 by a short channel

Channel (geography)

In physical geography, a channel is the physical confine of a river, slough or ocean strait consisting of a bed and banks.A channel is also the natural or human-made deeper course through a reef, sand bar, bay, or any shallow body of water...

 to the south. The lagoon's water is brackish.

The lagoon is surrounded by a densely populated region containing palmyra palms

Borassus flabellifer

Borassus flabellifer, the Asian Palmyra palm, Toddy palm, Sugar palm, or Cambodian palm, is native to South and Southeast Asia, in the Indomalaya ecozone...

, coconut

Coconut

The coconut palm, Cocos nucifera, is a member of the family Arecaceae . It is the only accepted species in the genus Cocos. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word...

 plantations, grassland

Grassland

Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...

, rice paddies and extensive vegetable gardens.

The lagoon has extensive mudflats and salt marshes. It is surrounded by mangroves, particularly Avicennia

Avicennia

Avicennia is a genus of flowering plants currently placed in the bear's breeches family, Acanthaceae. It contains mangrove trees, which occur in the intertidal zones of estuarine areas and are characterized by aerial roots. Species of Avicennia occur worldwide south of the Tropic of Cancer.The...

. The lagoon attracts a wide variety of water bird

Water bird

The term water bird or waterbird is used to refer to birds that live on or around water. Some definitions apply the term especially to birds in freshwater habitats, though others make no distinction from birds that inhabit marine environments. In addition, some water birds are more terrestrial or...

s including American Flamingoes, duck

Duck

Duck is the common name for a large number of species in the Anatidae family of birds, which also includes swans and geese. The ducks are divided among several subfamilies in the Anatidae family; they do not represent a monophyletic group but a form taxon, since swans and geese are not considered...

s, garganey

Garganey

The Garganey is a small dabbling duck. It breeds in much of Europe and western Asia, but is strictly migratory, with the entire population moving to southern Africa, India Santragachi and Australasia in winter, where large flocks can occur. This species was first described by Linnaeus in 1758...

, black-tailed godwit

Black-tailed Godwit

The Black-tailed Godwit, Limosa limosa, is a large, long-legged, long-billed shorebird first described by Carolus Linnaeus in 1758. It is a member of the Limosa genus, the godwits...

 and other shorebirds.