Hyacinth in Katraj lake persists; greens fear aquatic life will go extinct

PUNE Despite the efforts of the Pune Municipal Corporation (PMC) to clear the Katraj lake of hyacinth, experts and environmentalists fear local fish species will go extinct in the water body if the scenario persists

PUNE Despite the efforts of the Pune Municipal Corporation (PMC) to clear the Katraj lake of hyacinth, experts and environmentalists fear local fish species will go extinct in the water body if the scenario persists.

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The lake covers an area of 29 acres and is currently completely covered by hyacinth.

“The otherwise eutrophic lake inside the Rajiv Gandhi Zoological Park is getting polluted water from nearby areas. This is harmful to the aquatic fauna and the nature surrounding the lake,” said Dr Raj Kumar Jadhav, director, Rajiv Gandhi Zoological Park and Wildlife Research centre.

This man-made lake was constructed during the Peshwa era and is situated in south of Pune. It is a combination of two lakes, with the first acting as the sedimentation tank, from where water flows into the Katraj lake. “Dams on both the lakes have gates at the bottom, which are used to release excess water into the Ambil odha (stream),” Dr Jadhav explained.

“These days the water quality of Katraj lake is severely degraded due to polluted water from surrounding areas directly entering the lake. The lake is silted and covered by vegetation,” said Dr Hemant Ghate, retired professor of Zoology, Savitribai Phule Pune University.

Ghate added, “The biological quality of water has changed so much that we have lost native species of fish like Puntieus Deccaniensis, which was first found in Katraj Lake in the 1970s. This was a small fish, two inches long, but now the fish is gone. This is because of the hyacinth which is exponentially growing due to the untreated sewage in the lake. Sewage provides phosphate and nitrogen for the hyacinth to grow.”

On April 2, deputy chief minister and Pune district’s guardian minister, Ajit Pawar, directed the municipal officials to remove the hyacinth and desilt the lakes.

A 2019 study by Renu Arora and Prof Milind Gidde, department of environmental education and research, Bharati Vidyapeeth (deemed university), had stated that the lake needs proper management and a treatment process. “Removal of weeds by a natural process is important. The diversion of the drainage line is important. There is a need to place aerators in the lake that may help to control the fish death rates, because they are at an extinct level. If some precautions are taken, the aquatic life of the lake will survive,” the study stated.