In India, aquaculture has turned a sprawling lake into fish ponds

Kolleru Lake was long known for its biodiversity, but scientists say that ecosystem faces an uncertain future

Published January 23, 2022 8:29AM (EST)

Farmers examine their catch from a human-made fish pond. On Kollerlu Lake, ponds such as this were once limited to the shoreline and shallows. (Monika Mondal / Undark)
Farmers examine their catch from a human-made fish pond. On Kollerlu Lake, ponds such as this were once limited to the shoreline and shallows. (Monika Mondal / Undark)

This article originally appeared on Undark.

Until the 1980s, Kolleru Lake was a sprawling shallow body of water. At its deepest point during the monsoon season, the water only reached 10 feet, yet the lake covered a surface area of 350 square miles — roughly the size of Dallas, Texas. Located in the southeast state of Andhra Pradesh, Kolleru was among India's largest freshwater lakes. Known for its biodiversity, the lake was a popular stopover for migratory birds, such as flamingos, which fed from the shallows. Humans, too, derived sustenance from the lake: not just a wide variety of fish, but also rice. Local residents would sow seeds in the summer during the monsoon season and then harvest the rice later in the year, when the lake's boundaries had receded.

Today, many of those rice paddies are gone, and the flamingos are beginning to disappear, too, along with a myriad of other bird species. Instead, the region is marked with houses, shops, roads, and human-made ponds. On any given day, fish farmers tend to their stocks — tossing feed into the water, extending nets, and otherwise contributing to a growing aquaculture industry centered on carp and shrimp. As this industry has expanded, it has fundamentally reshaped the region's topography. These fish ponds, once limited to the shoreline and shallows, are now being built farther and farther into the lake. As a result, scientists say, the water has been severely degraded. And not only that: What remains for most of the year cannot rightly be called a lake.

"Open water we can see only during the monsoon period," said Meena Kumari Kolli, a geography researcher who earned her Ph.D. from the University of Marburg in Germany. Kolli has used GIS mapping techniques to study how the region has changed over the past few decades. Outside of the rainy season, she said, there are now only fish ponds, dry marshlands, and weeds — "the lake actually doesn't exist."

Aquaculture is the fastest growing food production industry in the world, according to the United Nations' Food and Agriculture Organization, and India ranks second globally in aquaculture fish production, contributing more than 8 percent of the world's farm-raised fish. Indian aquaculture has developed rapidly over the past few decades, said Joeri Scholtens, a fisheries researcher and an assistant professor at the University of Amsterdam. Scholtens says that this kind of rapid growth is unique to India and was possible only because of the nation's abundant natural resources and government subsidies. The subsidies were part of the country's Blue Revolution, a program initiated by the central government in the 1980s to boost the economy by increasing production of marine products.

That rapid development is a double-edged sword in Andhra Pradesh, India's top seafood exporter. Local communities overwhelmingly support aquaculture's expansion, but they also lament the loss of the lake as a source of food and drinking water. Scientists, meanwhile, insist that industry must be curtailed. They point not just to the pollution, but also to the dramatic declines in native fishes and migratory birds. The ecological imbalance will only get worse, they say, if the region's aquaculture is allowed to expand.

Land use map of Kolleru Lake in 2018. While the lake was a sprawling body of water until the 1980s, geography researcher Meena Kumari Kolli says now open water is only seen during the monsoon season. Visual: Kolli et. al / Water, 2020

* * *

Commercial fishing came to Andhra Pradesh in 1975, when the state allowed Kolleru Lake's shoreline and shallows to be converted to fish farms. In the ensuing decades, the international demand for fish and shrimp products rapidly expanded, and farmers increasingly transitioned from rice to aquaculture with the help of government subsidies. In the process, the aquaculture industry encroached farther and farther into the lake. Around the same time, in 1999, the region was named a sanctuary under India's Wildlife Protection Act. And in 2002, the Kolleru wetland was named a Ramsar site, a designation given to wetlands considered to be of international importance.

These forces — a rapidly expanding aquaculture industry and environmental protections — existed in tension with one another, and the conflict peaked in the early-to-mid 2000s, when the region was hit by severe flooding. The floods devastated the aquaculture industry, said S. Narendra Prasad, a former wetland researcher at the Salim Ali Center for Ornithology and Natural History in Hyderabad. Local scientists, who had long warned the government about the lake's environmental degradation, took the opportunity to call once again for greater regulation.

In 2006, the central government responded, launching Operation Kolleru, an effort that was to destroy many of the region's fish ponds for good. According to government records, no new ponds within the bounds of the sanctuary have been registered since 2006. In an interview with Undark, B. K. Das, the director of the Indian Council of Agricultural Research-Central Inland Fisheries Research Institute, said that "all the ponds around Kolleru Lake, as per the guidelines, have all be dismantled." Any problems with environmental deterioration have been taken care of, he added.

But this is only partly true. When the fish ponds were destroyed, local farmers were left without viable employment opportunities, said Kolli. And so many local residents rebuilt their ponds. This time, they didn't register those ponds with the government.

Biologist B.C. Choudhury was working at the Wildlife Institute of India in Uttarakhand when he went to the Kolleru region in 2011, as part of a government-led effort to consider downsizing the lake's wildlife sanctuary. By that point, said Choudhury, many aquaculture ponds were destroyed but others continued to exist. Regions where the water had once reached 3 feet deep now hosted ponds, buildings, and busy roads. The villagers wanted to push farther into the lake's center, creating new farms, effectively shrinking the lake even further. The committee, however, recommended against this. The committee's report was met with strong opposition, said Choudhury. "The economic interest is so overpowering that every other interest is to be sacrificed in the altar of that economic interest."

Facing pressure from local farmers and those in the aquaculture industry, the state government moved forward with a resolution to reduce the size of the lake and convened another expert committee in 2015 to study the potential impacts. The committee ultimately recommended that nearly 13,673 acres of private land be removed from the sanctuary. While the boundary change hasn't happened, recent satellite imagery still shows a remarkable picture from the sky: a region covered in dark green blocks — fish ponds.

From 2008 to 2018, fish production in Andhra Pradesh more than tripled. Last summer, the state announced that it will aim to triple current production.

* * *

On a sunny day last September, Akinen Satish Kumar and his crew of laborers were waiting adjacent to a pond, where leaping carp broke the surface of the water; other carp wiggled in 13-gallon buckets that would soon be sold. Kumar said his pond was a paddy farm until the late 1990s, when he dug out a pit and transformed it. What grows inside these mud-based ponds varies, but farmers in the Kolleru region mostly raise carp and shrimp.

When Kumar created his 1.5-acre pond, he was able to simply fill it with water from the lake or from a nearby river. But now those waters have become too salty — the result of pollution dumped locally and of sea water migrating from the Bay of Bengal. So Kumar adds a chemical treatment that makes the water suitable for fish growth. After harvesting the fish, he does what other nearby farmers do: He drains the chemical-laden water into what remains of Kolleru Lake.

When lake water isn't available, locals can access ground water, which in many cases is just 10 to 15 feet underground. But that water is degraded and not fit for drinking, said Krishna Raju Bale, a local resident who works at one of the fish farms. Now, Bale and others buy drinking water from the store or from one of the large trucks that transport clean water from a nearby town. But for some residents, buying water is an unaffordable luxury. Krishna Durga Bale (no relation to Krishna Raju Bale) gets her family's water from the ground or the lake, and when possible, she boils it. But, she said, her budget is tight and the cost of cooking gas is soaring. Sometimes it isn't possible to boil the water before consuming it. She and her family often suffer from fever, she said, and digestive problems — the direct result, she believes, of drinking the contaminated water.

A bulldozer attempts to remove weeds from the lake.
Farm laborers toss feed into the water from a boat.
Farmers preparing to weigh and sell their fish.
A fish pond, separated from another pond by a line of coconut trees.

Subrata Das Sharma, a geoscientist at the National Geophysical Research Institute in Hyderabad, has spent a decade identifying pollution in the lake and trying to understand its sources. Over time, he said, the water in Kolleru Lake and its tributaries has been depleted, opening up space for saltwater to fill in. That saltwater comes from the Bay of Bengal, which is more than 20 miles away. While this kind of saltwater intrusion has occurred in other water bodies, Das Sharma said, it usually only happens when the saltwater source is much closer, fewer than 5 miles away. The researcher has also found industrial pollution in his lake samples. In a 2020 paper, he identified possibly toxic metal ions like chromium, copper, manganese, and zinc — the result of aquaculture and other industries' dumping their waste directly into the lake.

Farmers are not unaware of the degradation. Sitting on a motorbike next to his 2-acre fish farm, a young man named Pavan Kumar acknowledged the pollution but said some level should be accepted. "If you want to grow that," he said, "we require some chemicals."

Locals have also observed the disappearance of native fish species. "Over the past 20 years, many fish species that could easily be found in the Kolleru region have disappeared," said a local laborer named Gokarneswarudu, speaking through a translator. (Like many Indians, he goes by just one name.) Now, he said, he can neither find enough fish in the lake nor enough work to sustain his family. He remembers how local species such as bullseye snakehead and catfish, both of which are used in curries, were once abundant, but now hard to catch.

S. Sandilyan, ​​a former fellow at the Center for Biodiversity Policy and Law in Tamil Nadu, said that these native species are declining because of pollution, habitat loss, and commercial fish, which sometimes escape from ponds and go on to thrive as invasive species.

Kolleru is also losing its birds, including migratory species such as painted storks and Siberian cranes. All the new development has transformed their traditional fishing spots and pushed out their preferred fish. In search of nourishment, some bird species try to feed from the aquaculture ponds — to the chagrin of the farmers. This has led to bird-human conflicts, said Goldin Quadros, a scientist at Salim Ali Center for Ornithology and Natural History, in Tamil Nadu. Quadros is referring specifically to the gun shots that periodically punctuate the region's soundscape. With every shot, birds startle then haphazardly fly away from the fish ponds.

"There could be some birds like pelicans which would adapt and feed," said Quadros. But small migratory birds depended upon the wetlands to serve as their refueling station. Those wetlands, Quadros said, are gone.

R.C. Bhatta, a marine economist based in Karnataka, said that India's Blue Revolution did not include money or create space for conservation and protection of native species. "The basic mandate remains to increase production," he said.

It's doubtful that the residents of Kolleru would support conservation, anyway — at least not in the absence alternative employment. In interviews, locals repeatedly expressed dismay whenever Operation Kolleru was mentioned. The government, Krishna Durga Bale said, likes birds more than its own people.

Still, scientists who have been studying the lake for years can't help but note the consequences that additional development will bring to this already degraded ecosystem. Soon, Kolli said, this once sprawling lake will entirely disappear.

* * *

Monika Mondal is an independent journalist based in New Delhi, India. Her work focuses on the environment, agriculture, and sustainability.

All photos by Monika Mondal for Undark.

This story was produced with support from Internews' Earth Journalism Network.

This article was originally published on Undark. Read the original article.

By Monika Mondal

MORE FROM Monika Mondal

Related Topics ------------------------------------------

Aquaculture Freshwater India Lakes Undark