沿岸生態系復元のための水環境整備；インド チリカ湖からの教訓

抄録

Chilika is the largest lake along the east coast of India and a designated Ramsar site. It is a unique assemblage of marine, brackish and fresh water ecosystem with estuarine characters. The highly productive lake ecosystem with its rich fishery resources and biodiversity sustains the livelihood of more than 0.2 million people in the local communities who live in and around the lake. The lake ecosystem was facing degradation due to alteration of fresh water flow, choking and shifting of the lake mouth coupled with accelerated siltation due to changes in the land use pattern and degradation of the drainage basin. This resulted in change of its ecological characters and it was added to the list of the Montreux Record in 1993 by Ramsar Bureau. Being concerned with this the Government of Orissa created Chilika Development Authority (CDA) in the year 1992, for the restoration and integrated management of the lake. CDA adopted a holistic approach by way of integration of coastal processes and the drainage basin into the adaptive management planning that evolved through a wide scale consultation and targeted scientific studies. The important outcome of the study was that the lake was turning into a freshwater ecosystem because of poor exchange with sea water. While CDA was looking forward for a solution, Ramsar Center Japan (RCJ) came forward to assist CDA to relate to Lake Saroma in Japan where effective solution to similar problem was achieved. Prof. T. Tsujii, participated in the 1st Chilika management-planning workshop in December 1998 and recommended to re-establish the connection to the sea as has been done in case of Lake Saroma in Japan for restoration of Chilika Ecosystem. Subsequently RCJ organized a technical visit of Chief Executive CDA and Director Wetlands International South Asia to Saroma in 1999 August. With the inputs and the experience learnt from Saroma, CDA went for the hydrological intervention by way of opening of a new mouth in October 2000. The intervention improved the hydrological regime resulting in enhancement of the lake productivity immensely. It demonstrates how hydrological restoration of a wetland can result not only in the improvement of the ecosystem but can immensely benefit the local communities. Chilika was removed from the Montreux Record and prestigious Ramsar Award was conferred on CDA in recognition of the exemplary restoration work carried out with the active involvement of stakeholders.