Growing silt load is turning out to be a major threat to the ecological character of the 1,100-sq km Chilika lagoon which is under tremendous pressure from increased tourism, destructive fishing practices, excessive dependence for livelihood and impact of climate change.
The first-ever integrated management plan for Chilika, developed by Wetland International, South Asia, and Chilika Development Authority (CDA), assesses that current siltation rate and sedimentation analysis point at the brackish water lagoon receiving huge silt loads. Possibility of the rising silt load changing the ecological character of the lagoon is calculated to be ‘high’.
While siltation is the concern, the change of land use patten within the basin of Chilika is affecting the trend drastically while further fragmentation of the flood plains have also contributed in an adverse manner. The management plan reveals that the problem could lead to loss of water- holding capacity of the lagoon thereby affecting the hydrological regimes.
The document, which was released here on Saturday, projects that an invasive plant species called ‘Phragmites karka’ is rapidly covering the northern sector of the lagoon where it is enhancing siltation and affecting fish breeding grounds, shifting vegetation belts apart from leading to health hazards for the communities. The level of threat posed by this factor is recorded as high.
Increasing sedimentation, shifting of littoral materials and tidal influence are also creating a serious problem for lagoon-sea connectivity. Coupled with water use changes upstream, this process can cause changes in salinity regime which in turn affects species migration and fisheries.
The management plan also looks at the threat posed by climate change which has affected precipitation patterns in the Mahanadi river basin. Variation in rainfall could adversely impact the salinity level which is key to the biological nature of the lagoon.
Of the eight key threats recorded in the document, at least five are tagged as high signifying the problems for the lagoon and the need for the management plan. Rapid increase in fisherfolks, number of boats deployed in the lagoon are also seen as major challenges since the current catch has already reached a sustainable level. “If not managed suitably, there is a high risk of over-exploitation of the sources with severe impact on community livelihoods,” the plan document said.
Similarly, a spiraling tourist inflow, poorly managed tourism and boats can exert severe stress on the Irrawady dolphins too.
The Wetland International and CDA have prepared an estimated Rs 370-crore budget for implementation of the management plan of which 58 per cent would be for the ecosystem conservation, with 41 per cent to catchment conservation, 9 per cent to water management and 8 per cent to biodiversity conservation.
Component on sustainable resources development and livelihood improvement is estimated at 37 per cent of the total budget. Of it, 17 per cent is earmarked for eco-tourism development, 7 per cent for sustainable fisheries development and 14 per cent for livelihood diversification and enhancement of quality of life of Chilika communities. The component on institutional development is estimated at 5 per cent of the overall budget.