an experimental basis. The slurry will have to be disposed of at least 20 km away from the coast.
In order to improve the biotic integrity at the downstream reaches of Periyar river system, increase of microhabitat diversity, in stream cover, improvement of water quality parameters development of riparian zone and improvement of the substratum are inevitable. The following management measures are proposed for restoration of fish microhabitats.
Sand mining activity at this stretch of the river system shall be stopped.
No more construction of boundaries with boulders in the riverbank
Ensure zero level effluents discharge from the factories. Levels of trace metals and heavy metals and other pollutants in the effluents should not exceed the standards prescribed by LAEC/PCB
IBI scoring shall be elevated to 50 and above by resorting to improving the water quality parameters, in stream cover, microhabitat diversity and quality of substrates.
Install different types of deflectors for improving the flow velocity and direction, which will, helps to increase the heterogeneity of in stream cover, microhabitats and substrates.
In stream and stream side cover shall be improved by boulder placement, placement of stumps, roots or debris, artificial undercut banks formed by overhanging cover structure, tree planting in banks and the removal of overhanging vegetation in the bank shall be stopped.
Substrate reinstatement by replacing the sediments with well-sorted gravels, cobbles or even with crushed rocks which will helps to improve the fish and invertebrate habitat
The micro invertebrates which forms a good source of food to stream fishes need to be improved by increasing the density of woody debris we land vegetation and restoration of riffle type microhabitats in streams. Restoration of Fish biodiversity and fisheries wealth
Transplant/Translocate the fish and crustacean species disappeared from the water body. This can be done by providing the required habitat of the respective species. The habitat suitability index models developed by the Scientist of Cochin University of Science & Technology can be utilized for such translocation of species.
Once the IBI scores are elevated to beyond 50, massive ranching of the region with hatchery produced seeds can be planned and executed. The following species are recommended for river ranching of the area. Giant prawn Macrobrachium rosenbergii, Crabs, Tiger prawn Labeo dussumieri, Puntius carnaticus, puntius sarana subnasutus, Clarian dussumieri, Indian major carps, Etroplus suratensis, Channa spp. Chanos chanos, Lates calcarifer. The ranching shall be done following scientific methods and techniques. The fringes of the river can be utilized for nursery rearing of the frys and fingerlings of the species selected for ranching. The nursery rearing and ranching shall be done with participation of local bodies, fishermen, NGOs etc; The success of these programmes are fully dependent on the participatory management by various stake holders.
Cage culture in the river proper.