panaji tribal communities living along the banks of the zuari and mandovi rivers have complained to the shah commission of inquiry that longterm miningrelated activities have severely impacted the breeding pattern of fish and their traditional livelihoods the original sandy layer on both river beds has been buried by heavy sediments of ore and other materials gomantak adivasi sanghatna president rajendra kunkolkar said this has adversely impacted the breeding grounds of rock fish and destroyed various species of shell fish in a petition to the shah commission kunkolkar has pointed out that in the last decade tribal communities have noticed a progressive decline in the breeding of fish and marine life in both rivers we are worried about our livelihood as the rivers may produce less fish and other marine life in the future intensive miningrelated activities barge building and repair workshops in the zuari movement of barges in both rivers and discharge of ballast water by ships at the mormugao harbour contribute to pollution and adversely impact the riverine ecology the gas stated in its petition fishermen claim that several fish species are on the verge of extinction though no study has been carried out to confirm it casting nets in the river mandovi opposite the old secretariat and both sides of its banks in chorao and ribandar would yield a heavy catch said secretary of all goa fishermens cooperative association vishwanath halarnkar but shrimps locally called as galmo and lobster prawns shivodd are scarce now he lamented the fish population in the river and its flood plains has reduced drastically the mandovi banks on either side are thick with mining silt this is where shrimps prawns and smaller marine life can be found halarnkar said dau mukund kunkolkar a senior villager from odxel taleigao said they used different methods of fishing ranging from the use of bare hands in the rocks and petromaxes to nets and canoes but now it is difficult to find crabs chonak and prawns even other species of fish have dwindled he said according to estimates there are around 250 to 300 fishermen in dona paula odxel cacra nauxim and bambolim many of them depend on shellfish especially oysters and mussels kunkolkar said a sizeable section of ageold fishermen from the community rely on traditional methods to eke out their existence the association has demanded that the mining of ore in goa be halted for five years till its impact is studied and negated the river beds should be desilted and the damage caused by ore deposition and ballast water discharge in both rivers must be repaired naturally for marine life to recover kunkolkar said the revenue from mining royalty has touched 800 crore per annum the footprints of shipbuilding yards in zuari bay have been studied by the national institute of oceanography nio he added it is well known that ballast water released by ships contains microbes and other organisms which contaminate our eco systems and damage our marine life the gas president