Jaffna Lagoon

The Jaffna lagoon is a semi-enclosed water body connected to the Palk Bay. It is surrounded by a dry zone land mass and due to being more greatly influenced by freshwater input, has different physical conditions to that of the larger Palk Bay. The lagoon contains a number of coastal wetland habitats and is an important breeding area for numerous marine species. Jaffna lagoon has been identified as an IBA by BirdLife International.

Kahandamodara Mangroves

Kahanda estuary is a branched shallow wetland with a few mangrove islands, comprising 215 ha of mangrove forest. The estuary opens to the sea through a narrow canal on the southern side and is rich in mangrove species. The consistently high water level has contributed to protect the dense mangrove vegetation around the estuary from human exploitation.

Kala Oya Estuary

Kala Oya estuary is a bay estuary, as the main stream of the Kala Oya and its tributaries discharge freshwater into the Dutch bay before entering the sea. The estuarine area includes the brackish water areas of Kala Oya, Dutch Bay and the Puttlam estuary. The amount of freshwater received is controlled by the water retention capacities of the tank system within the Kala Oya basin. Kala Oya estuary harbours the largest tract of intact riverine mangrove in Sri Lanka. This ecosystem functions as an important breeding ground for many marine species and is rich in biodiversity. Presently, the Kala Oya estuary is in good condition as the area is sparsely populated and partially borders the Wilpattu National Park.