PUNE, Nov 17: A large number of fish in Pawana river have died yet again. The civic authorities have yet to nail the causes behind the death of fish in two earlier incidents.Fish were found floating at the ghat near Moraya Gosavi Samadhi temple at Chinchwadgaon. Local corporator Raju Golande alleged that some fishermen were using gelatin underwater to catch fish. Earlier, the fishermen used nets but had switched over to gelatin, he said.Chief trustee of Chincwhad Devasthan Trust Vighnahari Dev Maharaj suspected that the fish may have died due to the overnight release of some poisonous industrial effluents. He said he had not heard any explosions.The civic medical officer K. Nagkumar who was coordinating the examination of the earlier samples of river water by the state health and few private laboratories is currently on a visit to New Delhi for a seminar on sustainable development of cities.In the two earlier incidents at Kasarwadi, the unchecked release of industrial effluents was suspected to be the cause of the dead fish floating.