Kendrapara: The district administration here razed 30 illegally erected prawn dykes and reclaimed nearly a hundred acres of encroached government land on the fringe of swampy mangrove forest cover.

Thirty illegal dykes measuring more than 100 acres were demolished. The gherries dismantled in Rangani gram panchayat had sprouted up in coastal regulation zone, said Rajnagar tehsildar Nihar Ranjan Mallick.

These illegal dykes were identified in a joint survey by revenue, forest and police personnel. Dyke builders were served notices to voluntarily dismantle the structures. As they failed, the structures are being demolished by the administration.

"The reclaimed land would be taken up for mangrove regeneration programme so that prawn farmers are not able reoccupy it. The forest department has been asked to undertake the plantation drive soon," Mallick said.

The reclaimed areas are conducive for mangrove regeneration as there is regular inflow of tidal waters.

The water-bodies subjected to encroachment are changing their directions and triggering erosion in various spots, said an official.

These unauthorised prawn dykes not only pose a hindrance to the flow of natural water-bodies but are also hazardous for aquatic animals, including freshwater fish, due to rampant use of chemicals.

In recent years, there has been a drop in fish yield due to such unauthorised activities, Mallick said.

"Water pollution caused from illegal fishing dykes has come to our notice. It's a matter of concern. We have asked the state pollution control board to inspect the sites," said an official.

The Bhitarkanika river system is connected to numerous creeks, water-inlets and nullahs before oceanic convergence. It proves conducive for shrimp farming.

As a result, there has been mushrooming growth of prawn dykes. All these prawn culture dykes were unlawfully installed without the mandatory approval of tehsil and marine fisheries wing authorities, alleged an environment activist.