Chilika shrinking! Massive siltation poses threat to Asia’s largest brackish water lagoon

Chilika Lake, the largest brackish water lake in Asia and the second largest coastal lagoon in the world, is shrinking at an alarming rate, posing a serious threat to its rich and unique biodiversity.

The lagoon which spreads over Puri, Khordha and Ganjam districts is slowly getting filled up due to siltation with alleged lack of maintenance by the Chilika Development Authority (CDA).

High rate of siltation in the lake has shrunk its size. According to government records, the lake has shrunk from 1100 sq km in 1914 to about 900 sq km, and the average depth has dropped from 2.4 m to less than 1.5 m.

As per reports, Chilika has moved 4-5 kilometres from the fishermen's settlement. At Mangalajodi in Tangi, where there was once a huge lake, there now remains only one channel for boat traffic in the name of lake today. With many areas drying up, fishing boats are lying in dry places. The fishermen are forced to fish in knee-deep water at many places of the lake.

“The lake was just behind my house during my childhood. We used to fish near my house. Now it has moved 7kms away. It is due to ‘Nala grass’. This grass has resulted in siltation and drying up of the lake. Earlier, more than 400 boats used go into Chilika every day. But now, barely 150 boats go to fish in the lake,” said a local fisherman Budhhi Behera.

Another local said, “Rain water cannot go and mix with Chilika because of the silt and Nala grass. If the obstruction can be removed, the lake will be able to breathe easily.”

These grasses are rapidly eroding and shrinking Chilika. Not just the grass, the ‘Rajadala’ is also growing inside Chilika. There are allegations that the ‘Rajadala’ is growing as the shrimp mafia is cordoning off large areas in inner Chilika.

Meanwhile, the Chilika Development Authority (CDA) has set up 33 stations to monitor the lake which has 52 tributaries connected to it. The CDA said the soil is being dug up with the help of excavator machines in the buried areas.

The CDA Chief Executive Officer (CEO), Amlan Nayak informed that Chilika, which had dried up during the rains, will return to its original state soon.

“We have 33 monitoring stations. We monitor the lake every month with the help of Wetland Research Centre at Barkul. Excavation and dredging are a continuous process. Even the ferry route of Janhikuda-Satapada is being dredged. Nala grass is an integral part of Chilika eco system. Many migratory birds lay their eggs in those tall grasses,” said Nayak.

The ecology of the already shrinking Chilika lake is further threatened by the scramble among fisherfolk, farmers and traders to grab their share of the depleting stock of fish and prawn.

The lagoon was enlisted as threatened ecosystem in 1993 by the Ramsar Convention due to its changing ecological characteristics. However, it was removed from the list in 2002 after the successful restoration of the lagoon by the CDA.