Once known to produce rice as beautiful as pearls for the King of Kotte, the Muthurajawela Paddy fields were made uncultivable allegedly by the seepage of sea water through Dutch made Canals and were left to death and decay.
But the nature had spread its healing touch over the last 200 years had turned once a discarded paddy fields into a biodiversity hot spot today attracting ecologists, birdwatchers, students, eco-photographers , tourists, poachers and fishermen.
Spread over 6230 hectares The Muthurajawela wetland runs parallel to the western coastline of the country and together with the contiguous Negambo lagoon forms an integrated coastal wetland system of high biodiversity and ecological significance.
It is listed as one of the 12 priority wetlands in Sri Lanka, and in 1996 in recognition of its high ecological significance the northern section of Muthurajawela was declared a Wetland Sanctuary. The Sanctuary contains a high diversity of both flora and fauna, including several endemic and nationally threatened species, and also provides an important area for migratory birds.
Nearly 200 species of flora belonging to seven major types namely marsh, lactic flora, shrub land, reed, swamp, grasslands, stream bank and mangrove forest is found in Muthurajawela Wetland zone including one endemic species, Arecacea or Phoenix zelanica.
The vertebrate fauna at Muthurajawela includes 40 species of fish, 14 species of reptiles, 102 species of birds and 22 species of mammals. Among the total number of vertebrate species documented 17 are endemic while 26 are nationally endangered. Among the invertebrates documented 48 species are butterflies and 22 species are dragonflies.
Birds are the dominant group of vertebrates in Muthurajawela with a total of 102 species including one endemic and 19 migrants. The mixture of vegetation types and aquatic habitats in Muthurajawela has made it a heaven for birds. Some of the wetland birds include Little and Indian Cormorant, Cattle, Little, Intermediate & Large Egrets, Purple Heron, Indian Pond Heron, Little Green Heron, Black-crowned Night Heron, Black Bittern, Yellow Bittern, Chestnut Bittern, Black-headed Ibis, Asian Open-bill, Little Grebe, Lesser Whistling Teal, Pheasant-tailed Jacana, White-breasted Water hen, Purple Swamp hen, Water Cock and Common Moorhen.
Some of the migrants and waders include Whimbrel, Eurasian Curlew, Common Sandpiper, Curlew Sandpiper, Marsh Sandpiper, Pintail Snip, Gull-billed Tern, Whiskered Tern, Little Tern and Lesser Crested Tern. Resident waders include the Red-wattled Lapwing, Greater Painted Snip and the Eurasian Thick-nee. Among the Kingfishers, White-throated, Stork-billed, Common and Pied Kingfishers are regularly spotted while the Black-capped Kingfisher, a rare winter migrant, has also been recorded.
Birds of prey at the wetland include the Shikra, Brahaminy Kite, White-bellied Sea-eagle and the migrant Western Marsh Harrier and Palled Harrier while the migrants include Indian Pitta, Blue-tailed Bee-eater, Asian Paradise Flycatcher, Asian Brown Flycatcher, Greenish Warbler, Brown Shirke, Forest and Grey Wagtail.
As well as sustaining important biodiversity this wetland complex provides a range of ecological and hydrological services.
It receives and retains high loads of domestic and industrial wastes, and sediment and silt loads, from both surrounding and upstream areas. Wetland plants facilitate sediment deposition, before water enters Negombo Lagoon acting as a filter for flowing waters and assisting the removal of nutrients and toxic substances, helping the Mother Nature to heal the wounds inflicted by humans.