| reference = and second largest coastal lagoon in the world, its area ranges from about 900 to 11,165 sq km during summers and monsoon respectively. Its salinity varies by region, from freshwater where rivers flow in, to oceanic salinity levels due to tidal influx.

Chilika is recognised as one of the best-managed Ramsar sites in Asia and received the Ramsar Wetland Conservation Award in 2002. Golabai provides evidence of a sequence of Chilika area culture in three phases: Neolithic (c. 1600 BCE), Chalcolithic (c. 1400 BCE to c. 900 BCE) and Iron Age (c. 900 BCE to c. 800 BCE). Radiocarbon dating traced the earliest level of Golbai to 2300 BCE. The site is located on the left bank of the Malaguni River, a tributary of the Daya River, which flows into Chilika Lake. This location, which gave access to the sea via Chilika Lake, gives evidence of the maritime activities of this region. The recovery of many woodworking adzes and other artifacts shows that Golabai was a boat-building centre. Golabai is the only excavated site in Odisha where boat building has been revealed. This also indicates that Chilika lake was close to Golabai and it facilitated the maritime trade of people in the area during the ancient period.

Ancient texts say the southern sector of Chilika was a major harbour for maritime commerce, when Kharavela (c. 209 BCE–after 170 BCE), the King of Kalinga, was known as the "Lord of the Sea".

Ptolemy (150 CE), the Greek geographer, referred to Palur as the port Paloura, located close to the point of departure situated outside of the southern tip of the lake at Kantiagarh, from where ships bound for different parts of Southeast Asia, sailed. After 639, the Chinese pilgrims Fa-Hien and Hiuen-Tsang mention a famous port "Che-li-ta-loChing" near the shore of the ocean which was a thoroughfare and resting place for seagoing traders and strangers from distant lands. This port was located at 'Chhatragarh' on the banks of Chilika Lake.

Archeological excavations discovered seventh-century ship anchors and stone memoirs dedicated to battle heroes at a village named Kanas, about north of Chilika on the banks of Nuna river, which flows into the lake. This gives evidence of a historic naval engagement off the coast.

A 10th-century text, the Brahmanda Purana, mentions Chilika Lake as an important centre of trade and commerce, and a shelter for ships sailing to Java, Malaya, Singhala, China and other countries. This suggests that the lake was then deep enough for berthing seagoing ships and had a channel to the sea big enough for loaded trading ships embarking to Southeast Asia. The villagers around Chilika Lake still observe an annual festival called "Bali Yatra" (Journey to Bali).

In 1803, the British entered the shores of the lake, reached Puri and occupied Odisha with the help of Fateh Muhammed. Fateh Muhammed, in turn, was rewarded by the British with freehold of the areas of Malud and Parikud, of the present day Garh Krishnaprasad revenue block.

</blockquote>Chilika is an integral part of the culture of coastal Odisha. Almost 400 years ago, the saint poet Purshottam Das, a devotee of Lord Jagannath, wrote a poem about Lord Krishna dancing with a milkmaid called Maniki, who had come to sell curds on the banks of the Chilika.

Geology

The lake is of estuarine character in an ephemeral environment. Geological studies indicate that the coastline extended along the western shores of the lake in the Pleistocene era with its northeastern region lying under the sea. That the coastline has moved eastward over the ages is supported by the fact that the nearby Konark Sun Temple, built originally on the seashore a few hundred years ago, is now about , away from the coast.

The catchment area of Chilika lake has a rock, sand and mud substratum. It contains a wide range of sedimentary particles such as clay, silt, sand, gravel and shell banks but the major part of the catchment area is silt. Around 1.6 million metric tons per year of sediment is deposited in Chilika lake by rivers Daya and several streams.

Geography and topography

thumb|250px|right|This map of Chilika Lake showing Nalaban Island, Chilika Bird Sanctuary, Dolphin Sanctuary, [[Puri town and Malud peninsula.]]

thumb|250px|Chilika Lake-central & west<br />1958 Topographic map, 1:250,000

thumb|250px|Chilika Lake-east end

thumb|250px|Chilika Lake

thumb|250px|Jetty at Satapada, Chilika Lake, Odisha

thumb|right|250px|Chilika Sea mouth

Chilika Lake is a shallow bar-built estuary with large areas of mudflats. The western and southern margins of the lake are fringed by the Eastern Ghats hill range. formed by northerly currents in the Bay of Bengal, resulted in the formation of this shallow lake and forms its eastern side. As an ephemeral lake, its water surface area varies from in the summer monsoon season to in the winter dry season.

The water spread area of the lagoon ranges between during the monsoon and summer respectively. A long, narrow, outer channel connects the lagoon to the Bay of Bengal, near the village Motto. More recently, a new mouth has been opened by Chilika Development Authority (CDA) which has brought a new lease of life to the lagoon.

The lake has numerous islands. The larger islands, separated by shallow channels, lie between the barrier and the main body of the lake. A total of channels connect the lake with Bay of Bengal.

The north shore of the lake is part of Khordha District and the western shore is part of Ganjam District. Due to siltation, the width of the barrier has fluctuated and the mouth to the sea has periodically been closed. The location of the mouth has also frequently shifted, generally towards the northeast. The mouth, which was wide in 1780, was only forty years later. The local fishermen, to maintain their livelihood, had to cut open the mouth to gain access to the sea for fishing. is the longest lake (if the length is considered, where the length of Chilika Lake is ) in India.

Hydrology

Three hydrological subsystems control the hydrology of the lake. The land-based system comprises distributaries of the Mahanadi River on the northern side, 52 river channels from the western side and the Bay of Bengal on the eastern side. Two of the three southern branches of the Mahanadi River that trifurcates at Cuttack, feed the lake. 61% () of the total freshwater inflow into the lake is contributed by these two branches.

The second drainage system which is non–perennial accounts for 39% () of the inflow. The important rivers of this drainage system are the Kansari, Kusumi, Janjira, and Tarimi rivers. The annual total surface freshwater input to the lake is estimated to be including direct precipitation over the lake contributing

All the inland river systems disgorge an annual flow of about of freshwater which is estimated to carry 13 million metric tons of silt into the lake. On the northeast, a channel connects the lake to the Bay of Bengal.

A tropical monsoon climate prevails over the drainage basin area of the lake. The lake experiences South–west and North-east monsoons during June to September and November to December respectively with an average annual rainfall of , with 72 rainy days. The maximum temperature of and minimum temperature of have been recorded.

Sediment quality

The Chilika Development Authority (CDA) established an organized system of water quality measurements and limnological investigations indicating the following physico–chemical characteristics of the lake waters.

Sediment cores were collected from different locations of the lake. The result indicated spatial variation of sedimentation rate in three zones of the lake of /year (Northern Sector), /year (Central Sector) and /year (Southern Sector). The non–uniform sedimentation rate along with the porosity and water content of the sediment cores were also analysed which indicated the lake had different deposition zones, with comparatively higher sedimentation rate in Northern and Central Sector and a slow rate in the Southern Sector.

Conservation&nbsp;– threats and management

In 1971, during Indira Gandhi's tenure as Prime Minister of India, Chilika Lake was designated the first Indian wetland of international importance under the Ramsar Convention due to its rich biodiversity as shown by the facts that:

  • Over a million migratory waterfowl and shorebirds winter here.
  • Over 400 vertebrate species have been recorded.
  • As an estuarine lagoon, it supports a unique assemblage of marine, brackish and freshwater species.
  • Several rare and endangered species are found in the region.
  • The lake supports fisheries that are the lifeline of the community.
  • The lake is of great value in preserving genetic diversity.
  • There is an Increase in weeds and aquaculture activities.

Threats

Over the years, the ecosystem of the lake encountered several problems and threats such as:

  • Siltation due to littoral drift and sediments from the inland river systems
  • Shrinkage of water surface area
  • Choking of the inlet channel as well as shifting of the mouth connecting to the sea
  • Decrease in salinity and fishery resources
  • Proliferation of freshwater invasive species
  • An overall loss of biodiversity with decline in productivity adversely affecting the livelihood of the community that depended on it
  • Fights between fishermen and non-fishermen communities about fishing rights in the lake and consequent court cases

The expansion of commercial aquaculture of prawn has contributed to the decline of the lakes fisheries and bird population.

Concerted action was initiated by the Odisha State Government with support from the Government of India to adopt adaptive conservation and management actions. Opening of the new mouth provided a favorable increased salinity regime throughout the lake with less fluctuations and improved water clarity.

Flora and fauna

thumb|Migratory birds at Chilika lake

The ecological richness of the lake is of value in preserving the genetic diversity because of the multiplicity of its habitat, flora and fauna (see photo gallery).

Flora

Recent surveys revealed 726 species of flowering plants belonging to 496 genera and 120 families. This represents about one fourth of the vascular plant species of the Odisha state where some 2900 species altogether are found.

The flora is dominated by aquatic and sub-aquatic plants with Fabaceae as the dominant plant family followed by Poaceae and Cyperaceae. Certain species were found to be characteristic of specific islands.

Important species identified are:

The lagoon hosts over 160 species of birds in the peak migratory season. Birds from as far as the Caspian Sea, Lake Baikal, Aral Sea and other remote parts of Russia, Kirghiz steppes of Kazakhstan, Central and southeast Asia, Ladakh and Himalayas come here. These birds travel great distances; some of them possibly travel as much as to reach Chilika Lake.

Birds like White bellied sea eagles, greylag geese, purple moorhen, jacana, flamingos, egrets, grey and purple heron, Indian roller, storks, white ibis, spoonbills, brahminy ducks, shovellers, pintails, and more are found here.

Migratory waterfowl arrive here from as far as the Caspian Sea, Baikal Lake and remote parts of Russia, Mongolia, Ladakh, Siberia, Iran, Iraq, Afghanistan and from the Himalayas.

According to a survey, 45 percent of the birds are terrestrial in nature, 32 percent are waterfowl, and 23 percent are waders. The lagoon is also home to 14 types of raptors. Around 152 rare and endangered Irrawaddy dolphins have also been reported. Plus, the lagoon supports about 37 species of reptiles and amphibians.

In 2007, nearly 840,000 birds visited the lake, out of which 198,000 were spotted in Nalbana Island. On 5 Jan 2008, a bird census involving 85 wildlife officials counted 900,000 birds of which 450,000 were sighted in Nalabana. Removal of invasive species of freshwater aquatic plants, especially water hyacinth, due to restoration of salinity, is a contributing factor for the recent increasing attraction of birds to the lake.

;Nalbana Bird Sanctuary

Nalbana Island is the core area of the Ramsar designated wetlands of Chilika Lake. Nalbana means a weed-covered island In the Odia language. It is a major island in the center of the lake and has an area of <!--it is pretty strange, stretching my credulity to the limit, that the result here is 6.00 square miles; this is likely an overprecise conversion being converted back, and if so should be changed. Yes, there is a chance, albeit slim, that this is mere coincidence. -->. The island gets submerged during the monsoon season. As the monsoon recedes in the winter, lake levels decrease and the island is exposed, birds flock to the island in large numbers to feed on its extensive mudflats. Nalbana was notified in 1987 and declared a bird sanctuary in 1973 under the Wildlife Protection Act.

Aqua fauna

As per the Chilika Development Authority's (CDA) updated data (2002), 323 aquatic species, which includes 261 fish species, 28 prawns and 34 crabs are reported out of which sixty five species breed in the lake. 27 species are freshwater fishes and two genera of prawns. The remaining species migrate to the sea to breed. 21 species of herrings and sardines of the family Clupeidae are reported.

Microalgae, marine seaweeds, sea grasses, fish and crab also flourish in the brackish water of the Chilika Lagoon. Recovery of seagrass beds in recent years is a welcoming trend which may eventually result in re-colonization of endangered dugongs.

thumb|right|250px|[[Wallago attu&nbsp;– A common type of fish in the lake]]

Between 1998–2002, 40 fish species were recorded here for the first time and following the reopening of the lake mouth in 2000, six threatened species have reappeared, including:

  • Milk fish (Seba khainga),
  • Indo-Pacific tarpon (Panialehio),
  • Ten pounder (Nahama),
  • Bream<!--Rhabdosargus berda--> (Kala khuranti),
  • Hilsa (Tenuealosa) ilisha (ilishi) and
  • Mullet R. corsula (Kekenda) and one of only two lagoons in the world that are home to this species.

Some Irrawaddy dolphins used to be sighted only along the inlet channel and in a limited portion of the central sector of the lake. After the opening of the new mouth at Satapada in 2000, they are now well distributed in the central and the southern sector of the lake.

Since 2004, the Whale and Dolphin Conservation Society has been conducting a science-based community education project to conserve the Irrawaddy dolphins and Chilika Lake. They have determined the primary cause of mortality for this population of dolphins is floating gill nets and hook line fisheries and the secondary cause is boat strikes from increasing unmanaged tourism activities. Castnet fishing with the help of Irrawaddy dolphins in upper reaches of the Ayeyawady River has been documented.

Major attractions

The 15&nbsp;km<sup>2</sup> Nalaban Island is within the Lagoon and is the core area of the Ramsar designated wetlands. It was declared a bird sanctuary under the Wildlife Protection Act in 1973. It is the heart of the park where one can see thousands of birds descending during the migratory season. The island disappears during monsoon season due to inundation, and post-monsoon, the island emerges again.

The lake harbours 225 species of fish, a variety of phytoplankton, algae and aquatic plants, and also supports over 350 species of non-aquatic plants. The other areas where high concentrations of birds are recorded are Gerasara, Parikud Island, and the western shores of the northern sector.

Eco-tourism

The open air and scenic natural flora and fauna of the lake are an attraction for eco-tourism. This is expected to provide a degree of alternate employment to the local community and generate environmental awareness, among local residents as well as visitors, about the conservation and wise use of the lake's natural resources. The locations within the lake identified for such activity are:

  • Rambha Bay at the southern end of the lake with the group of islands including:
  • The Becon Island, with an architectural conical pillar (to put a light on the top) built by Mr. Snodgrass, the then collector of Ganjam of the East India Company, on a mass of rock in the Rambha Bay near Ghantasila hill. It has scenic water spread surrounded by the Eastern Ghat.
  • The Breakfast Island, pear-shaped, known as "Sankuda island", with remnants of a dilapidated bungalow constructed by the King of Kalikote, has rare plants and is full of greenery with appealing flora.
  • Honeymoon Island, from Rambha Jetty, known as Barkuda Island, with clear waters has abundant red and green macro algae in the bed is also known for the limbless lizard, an endemic species found here.
  • Somolo and Dumkudi islands, located in the Central and Southern sectors of the lake, in the backdrop of scenic Khalikote hill range, are inundated remnants of the Eastern Ghats with rich flora and fauna and also known for sighting of Irrawaddy dolphins.
  • Birds' island, located in the southern sector of the lake has huge exposed hanging rocks, are painted white due to folic acid of the droppings of the birds and is known for rich algal communities and few mangrove species and also migratory birds in winter.
  • Parikud is a group of composite islands in the Garh Krishnaprasad Block for nature lovers and provides an avian spectacle during winter season
  • Kalijai Temple located on an island is considered to be the abode of the Goddess Kalijai. This temple is located at a hill which is surrounded by blue water bears. Local people of Chilika refer to goddess as the reigning deity of the lagoon
  • Satapada village, at the new mouth of the lake, provides a view of the Lake and also views of the dolphins. Hundreds of boats here provide tours of the lake for tourists.
  • Barunkuda, a small island situated near Magarmukh, the mouth of the lake, has a temple of Lord Varuna.
  • Nabagraha is an ancient deity located along the outer channel.
  • Chourbar Shiva Temple is located near Alupatna village, along the outer channel.
  • Manikapatna, located on the outer channel has historical evidence of a port which was used for trade with Far East and also has the Bhabakundeswar temple of Lord Shiva, an old Mosque whose entrance door is made of the jaws of the whale.
  • Sand-Bar and Mouth of the Lake is a striking and un-explored stretch of of empty beach across the sand bar which separates the Lake from the sea.
  • Mangalajodi a famous bird sanctuary for sighting migratory birds.

Tourist trap and scam reports

Recently Chilika Lake has gathered a reputation to be a tourist trap where a number of individuals run pearl and gemstone scams.[https://www.youtube.com/watch?v=hVQH6sPyW68]Chilika Lake gemstone scam in India

Access

thumb|250px|right|Chilika railway station

The lake is connected by road to Chennai and Kolkata through National Highway No 16. Satpada town on the eastern bank of the lake is about by road southwest of the city of Puri and at a distance of from Bhubaneswar, the capital of Odisha, which is also the nearest airport.

A broad-gauge railway line of the South Eastern Railway from Kolkata skirts along the western bank of the lake passing through Balugaon, Chilika and Rambha stations.

There are OTDC Guest houses at Barkul, Rambha, Satapada & several hotels at Balugaon. Before entering into the Nalbana Bird Sanctuary one has to obtain an entry permit. The entry permit has to be produced at entry/exit points, at check gates as and whenever requested by officials.

Published accounts

Film

Akanksha Damini Joshi's film, Chilika Bank$ (2008) tells the story via a banyan tree on the banks of lake Chilika tracing the ecological changes in the lake over four decades. From 1970s, when it was exposed to poaching by the outsiders, through 1980s when the lake was over-fished, to 1990s when the aqua culture ponds became a common sight, and finally the first decade of the 21st century when the environmental interference that was made to protect the lake ended up becoming its greatest threat.

Joshi's film maps the destruction of the lake and its abuse for the past four decades. The locals have been looted of their life support system with migration now being their only recourse. The film provides account of how uncontrolled human intervention has turned the lake, which was a sustainable livelihood resource, into a mere waterbody that tourists can dip their feet into.

The film produced by Public Service Broadcasting Trust was honored with the Livelihood Award at the CMS Vatavaran Environment and Wildlife Film Festival, New Delhi in 2009. It was recipient of the First Prize at Jeevika, South Asia Documentary Film Festival. Chilika Bank$ was screened in the Indian Panorama section of the 40th International Film Festival of India (IFFI), Goa 2009 in the non-feature film category. The film has garnered multiple television screenings on India's public broadcaster, Doordarshan's various channels.

The film was an Official Selection at the Film South Asia, Kathmandu in 2009, the Rodos EcoFilms International Festival,Greece in 2010 and the 4th Samsung Women's International Film Festival, Chennai in 2011.

Chilika Banks is displayed in various renowned university libraries like the Harvard University, Washington University, Duke University, Emory University and Syracuse University; and the Library of Congress, de facto the National Library of United States of America.

<gallery>

File:Sanderlings Im IMG 9382.jpg|Sanderling, Calidris alba

File:Terek Sandpiper I IMG 9379.jpg|Terek sandpiper, Xenus cinereus

File:Kentish plover I2 IMG 9384.jpg|Kentish plover, Charadrius alexandrinus

File:Northernshoveler-Chilika.jpg|Northern shoveler, Spatula clypeata

File:Lesser Flamingos I3 - Chilika IMG 9295.jpg|Lesser Flamingos, Phoenicopterus minor

File:Migratory Flamingos at Chilika.jpg|Migratory Flamingos at Chilika

File:Black tailed Goodwit at Chilika I5 IMG 9350.jpg|Black-tailed godwit, Limosa limosa

File:Pied Kingfisher at Chilika I IMG 9396.jpg|Pied kingfisher, Ceryle rudis

File:CorroboreeSeaEagle.jpg|White-bellied sea eagle

File:Parikuda Iseland Chilika.jpg|Parikuda Island

File:Balugaon on Chilika, Odisha, India.jpg|Balugaon

File:Red Crab at Chilika.jpg|Red Crab at Chilika

File:Aerial satellite imagery of Chilika lake, Odisha.JPG|Aerial satellite imagery of Chilika lake

</gallery>

References

  • Irrawaddy dolphin&nbsp;— India. Whale and Dolphin Conservation Society.
  • Chilika Lake - Heritage Tours Odisha (Recognised by Odisha Tourism & Ministry of Tourism Government of India)
  • Opening of new mouth and IRS 1D LISS III Image of Chilika Lagoon
  • Figure 1 Chilika Lagoon Basin
  • Tourist locations in the lagoon