A Coastal wetland of Semi-Natural origin located in the Dry Zone of the North-Western province. The area includes a cluster of coastal and marine wetlands and patches of arid zone dry thorn scrub, arid zone pastures and maritime grasslands, and sand dunes.. The mosaic of wetland habitats is also located within the Central-South Asian migratory bird flyway making it one of the most important bird habitats in Sri Lanka. The vegetation in thorn scrub consists of two distinct strata; a tree layer dominated by Acacia planifrons, Salvadora persica and Tamarindus indicus, and a shrub layer with species such as Azima tetracantha, Cassia auriculata, Dichrostachys cinerea, and Flueggea leucopyros. The shallow seasonal water holes contain algal species and submerged vegetation such as Najas marina. The single perennial tank in the area is home to floating plants such as Nymphaea stellata and Nelumbo nucifera. The patches of degraded fringing mangrove in this area are dominated by species adapted to high-saline conditions (i.e. Avicennia marina). The shallow margins of lagoons and seasonal water bodies are covered with patches of salt-marsh vegetation consisting of Halosarcia indica, Salicornia brachiata and Suaeda spp. The sand dunes and sandy sea-shore adjoining the lagoon support sparse Spinifex littoreus and Hydrophylax maritima dominated vegetation. The shallow lagoon has patches of sea-grass beds. The tidal effect in the shallow lagoons results in the exposure of tidal mudflats, consisting of very rich organic matter that supports a high richness of invertebrates, which in turn attracts diversity of water birds. A total of 149 bird species have been recorded from this area, including a large number of migratory species, amounting to more than 20,000 individuals annually. Large populations of Phoenicopterus roseus, Anas penelope, Anas acuta and Limosa limosa have been observed in the site. A notable species in this site is the Indian Spot-billed Duck (Anas poecilorhyncha), of which a breeding population was discovered recently. Until 2003, this species was known as a very rare migrant. Two species of rare migratory waterfowl are Anas strepera and Sarkidiornis melanotos. The patches of fringing mangroves in the area consist of Avicennia marina, Aegiceras corniculatum, Excoecaria agallocha, Clerodendrum inerme, Rhizophora mucronata, Lumnitzera racemosa and Pemphis asidula. The patches of sea grass beds scattered in the lagoon consist of Enhalus acoroides, Thalassia hermprichii, Halophila ovata and Halodule uninervis. This area is sparsely inhabited except for a few permanent settlements in the Thiruketiswaram area, but is historically significant due to the location of several ancient harbours. It is believed that the first Indian settlers in Sri Lanka arrived in the Mannar area. Collection of fuel-wood and livestock grazing is done on a small scale. These wetlands play an important role in nutrient cycling within the southern Palk Bay area and are connected to the extensive coastal and marine ecosystem complex of the Palk Bay and Gulf of Mannar.

Vankalai Triangle Related references