Morning walkers going to Ambazari lake embankment have been noticing a curious phenomenon over the last few days. Fish dying in thousands and floating on the surface of the lake water. Other fish ‘coming up for air’ and gasping near the banks of the water.
Such a menace this has become that water has begun smelling foul with the rotting dead fish. Because of the bad odour regular swimmers of Ambazari have been put off and not entered the lake to swim as usual in the mornings.
About a month ago, the same thing had happened at Gandhi Sagar ( shukrawari) Talab. Fish had died in thousands with no known cause.
NT spoke to a Fisheries expert Dr. Belsare, who was Senior Scientist and Head, Research of Marine biol research institute &college of fisheries and Professor of Fisheries at Konkan Vidyapeeth.
“Why are the fish dying in thousands?” We asked him.
“Fishermen’s greed and illegal fishing” he replied. “Actually there are a number of reasons why fish are dying now” he added. To outline his reasoning, what is happening is this –
Previously Ambazari lake was meant for drinking water and fish breeding was not allowed in it. But it did have some naturally occurring fish, which was illegally ‘harvested’ by fishermen. The underwater vegetative growth and quality of eco life and diversity was so rich that naturally bred fish thrived in it. Once the lake stopped being as drinking water resourced, it became primarily a fish breeding zone for the fishing community living nearby. Now, the logical population of fish in any aqua body should not exceed 5000 fish per hectare of lake water, which means 5000 fish in two and half acres or roughly 2000 fish per acre. But fishing is so lucrative,requiring no expense really, that the fishing community got greedy. They buy baby fish – of Katla and Rohu variety – from Calcutta and Hyderabad, where you get barrel of 2500 baby fish for just Rs. 750/. Which means just over a paisa per fish! They bring such barrels and just empty it into the lakes of Nagpur by thousands, with no accountability. No one knows who is putting how much fish here – the population could have become even 50,000 fish a hectare!
In the beginning, all the fish thrives since Ambazari has very good plant life and atmosphere for it. Within a year, a Rohu can become almost 1.5 Kg from a few grams. Then it goes on to become 5 Kgs or more in some more years. Fishermen can legally or illegally catch this fish and fetch a handsome price for it in the market. Depending on the size of the fish it can be Rs. 200/ to Rs. 400 per Kg. So just imagine the profit margin with hardly any investment! (No fish food to be fed, no fertilizer, pesticide or any lake maintenance).
But because of the overcrowding, natural fish food becomes scarce and fish can get starved, especially the smaller fish.
Fish woes are added when atmosphere gets cloudy or cold
Dr. Belsare explained that there is a natural layer of gas underwater caused by decaying marine plants on the floor of the lake. In cloudy weather, these gases rise to the surface and create a toxic atmosphere. Oxygen becomes scarce and fish start gasping for air – the very thing that was noticed to morning walkers.
Secondly, when water gets suddenly cold, the Ph ( acidity level) of water changes rapidly, which also causes fish death.
Thirdly, when there is no Sunlight, photosynthesis does not take place and underwater plants stop their growth. This again leads to scarcity of food for fish.
In addition to all the natural causes, foul play cannot be ruled out too. If someone has lost fishing rights of a particular water body to another, they can deliberately poison the water by throwing in lethal pesticides.
But this may not be happening to a large extent, since lots of fishing folk fish illegally. The banks of Ambazari are so vast for instance, that they can fish from any spots which are isolated and remote; they cannot be stopped.
Dr. Belsare pointed out that Government actually offers a lot of subsidies and grants to fishermen to develop fishing in natural rivers and lakes of Vidarbha. Nets are available on subsidy; they get aid in buying/ building boats. They should make use of such schemes and fish judiciously rather than falling prey to greed and taking short cuts.
In the long run it will be detrimental to both marine life and the fishing community. Local authorities should also get more vigilant about what goes on, but that is a tough call.
