Jalpaiguri, Dec. 27: The Central Inland Fisheries Research Institute has confirmed that presence of abnormally high rate of endosulfan in the Karala had killed thousands of fish belonging to 33 species on November 28. The finding was mentioned in a 26-page report sent by the Calcutta-based institute to the assistant director of fisheries here. “The abnormal content of pesticides recorded in fish samples can be considered a definitive cause for such large scale fish mortality in Karala river,” reads the report. The report was prepared after the institute had conducted tests on samples of water and dead fish collected from the river in Jalpaiguri. “We received the report from the CIFRI today, mentioning that pesticides were found much above permissible limits in the Karala water samples and the dead fish (see chart). We will soon forward the report to the Jalpaiguri district magistrate,” said Sonam Schewang, the assistant director of fisheries of Jalpaiguri district. The Barrackpore-based institute has also found that the water samples, especially those collected from the areas where the river is fringed with tea gardens, contained two other insecticides also. “But these pesticides did not pose any threat to the aquatic organisms. The report clearly says it was endosulfan that had contaminated the water and killed the fish,” said a fisheries department official. The report also lays down certain steps to clean up the Karala and increase the fish population in the river. “The institute has said fresh water should be pumped into the Karala to bring down the level of contamination and fingerlings should be released in the river before the rainy season to increase the fish population. The report also says the civic authorities should keep a check on the dumping of garbage from marketplaces, households and hospitals in the river,” said the fisheries official. The authorities had sought to add a new lease of life to the Karala by pumping in water from the Teesta after the fish had floated up dead. The two rivers flow just a few hundred metres apart in Jalpaiguri before the Karala empties into the Teesta a few kilometres from the town. But the Karala is still a veritable rubbish dump in Jalpaiguri with houses and markets continuing to deposit garbage in the river. “We have cleaned up the river and removed all the dead fish. We cannot keep the Karala pollution-free if the residents continue to dump waste in the river. We don’t know what we can do to salvage the river,” said Mohon Bose, the chairman of Jalpaiguri municipality. “The people should understand that if the river is not kept clean, similar situations (of dead fish floating in water) might occur again. Nevertheless, the civic body will soon launch a campaign to put an end to waste dumping in the river.”