Tamil Nadu is one of India's top three fish-rearing states, but the large number of fishermen it has dilutes the scope for fishing to become a heavily profitable business. This has led to serious competition among fishers and led to several destructive fishing practices such as the use of dynamites and bottom trawling.

But, fishers from Tharuvaikulam, a small village in Thoothukodi district, have been quietly practising sustainable fishing for years and reaping profits — economical, social and environmental. According to marine researchers, Tharuvaikulam is the only village in the state that relies purely on gill nets to fish.

Rajan (50), fisherman and owner of a boat at Tharuvaikulam said proudly, “For 16 years we have been fishing using only sustainable practices. We do not use trawlers or nets that scrape the bottom of the sea bed and destroy marine habitat. We use only gill nets for fishing. It traps only big, adult fish. This ensures that the juveniles have the time to grow, mature and breed, thus maintaining a healthy ecological balance.” Gill nets, as the name suggests, are designed to trap the fish by their gills.

The nets are hung in a way that when fish try to swim through it, their gills get caught in the mesh. The size of the mesh, however, is large enough for baby or juvenile fish to escape unhurt. This prevents bycatch or the trapping of baby fish and other marine wildlife that are not commercially important to fishermen.

Dr S Velvizhi, the principal scientist from MS Swaminathan Research Foundation (MSSRF), who has been closely monitoring fishing practices along the coast of Tamil Nadu said that by-catch accounts for about 30-40 per cent of a fisherman’s daily catch in villages around Tharuvaikulam.

“When these fishermen use normal mesh nets, they end up catching several molluscs such as oysters, clams and conches, small crustaceans such as crabs and barnacles, small fish, seaweed, sea grass and starfish which hardly have any market value. Hence, after hauling their catch, the fishermen collect the fish that will sell for a good price and discard the bycatch,” said Velvizhi.

“The mesh in gill nets are bigger mesh and that ensures that no other marine animal except adult fish are trapped in it, thus reducing bycatch by a hundred per cent. Not only does this ensure a better quality of haul for the fishermen, but also save other marine animals,” she added.

Explaining the transition to gill nets, Rajan said, “When we used cotton nets, we would catch fish and crabs that were small and would not sell in the market so we had to throw it away, but now, all the fish that get trapped in gill nets are big ones so we don’t have to waste time sorting through the catch. We feel good about allowing the baby fish to grow and sustain a healthy population.”

Antony Paneerdass is a 45-year-old fisherman who has been fishing in the shallow waters for 25 years while his brother-in-law prefers deep sea fishing. In any other fishing village, deep sea fishers earn a lot more than those that fish in shallow waters, but not in Tharuvaikulam. “We have an understanding with deep-sea fishers. Depending upon the time of the year, they will go fishing about once in a couple of months,” said Antony.

“When they venture out to the sea, they fish for about 10-15 days at a stretch and return with a bountiful catch which can make them profits worth Rs 1.5 lakh. The money is sufficient for them to last a couple of months. Meanwhile, shallow water fishers get an opportunity to catch sufficient amount of fish for themselves too,” he added.

In other villages, fishermen who make their catch from shallow seas rue that deep-sea trawlers take away a massive share of their fish. But in Tharuvaikulam, the mutual understanding among the villagers has strengthened a sense of social responsibility among them. “For long-term gain, it is important we look after each other. Five people with trawlers cannot take away the livelihood of 5,000 fishermen here,” said Antony.

Rajan goes on to tell us, “All the fishermen in our village understand we must fish responsibly and share marine resources. Any competition to catch fish will only result in depletion of their numbers and if the fish population decreases, so will our income.”

Fishing was not the only major source of income for Tharuvaikulam villagers. Between 1981 and 2002, a large number of villagers used to harvest corals from the shore and from an island a few kilometres off the mainland, called Koswari. It was after decades of mining that fishermen realised the island was shrinking in size. “The effect was gradual at first.

Later, the fallout was too drastic for us to not take note of it,” said Rajan who was one of the pioneers of coral mining during the 1980s.

“When we plucked and broke corals off the shore of the Koswari island, we began noticing that the soil was getting eroded quickly and the sea appeared to be eating into the land. After a few more years, we realised the island which was initially about 1.5 kilometres long had reduced to only 500 metres. It was a rude awakening for us,” said the port owner.

Antony added, “The government and other NGOs had been warning us not to harvest corals. But since it was easy income, we continued with it.

However, after realising the destruction we were wreaking, we decided to end coral mining in 2003.”

In coral mining, the conch shells and other corals that fishers collect were sold in the market as a raw material for the limestone industry. “During 1981-82, we used to sell one tonne of corals for Rs 100-150. It was a lot of money for us at that time,” said Antony.

Putting an end to coral mining meant losing out on a valuable means of income. “We suffered for a few months,” said Rajan. “Our income had reduced considerably and we needed to find other means to earn better using the resources available to us. That meant that we had to have a better grasp of fishing,” he added.

However, in 2004, something happened. The tsunami became the catalyst that cemented the resolve of the fishers here to preserve corals and follow sustainable fishing practices.

“We saw the difference in the impact of the tsunami in areas with corals and reefs and in areas without them. It reinforced our determination to preserve corals,” said Antony.

A study recently concluded by Suganthi Devadason Marine Research Institute found that coral mining was a major factor that caused soil erosion in Thoothukudi’s cluster of islands. Dr Edward Patterson, the director of the Institute, said “The fishermen of Tharuvaikulam may not have the advantage of scientific data, but from experience, they have been able to understand that the size of Koswari island was decreasing and that it was caused because of coral mining.”

“Corals are biological barriers that protect both islands and the mainland from strong coastal waves and currents. With them gone, the soil gets exposed and is rapidly washed away by the ocean,” Patterson said.

Gabriel Grimsditch, the Programme Officer for Marine and Coastal Ecosystems from United Nations Environmental Programme (UNEP), said, “It is extremely important for fishing communities to understand the effects of destructive fishing on coral reefs. Destructive fishing practices reduce the complexity of reef habitats by destroying coral colonies and other reef organisms, and this means that there is less habitat for fish and thus less productivity.”

Speaking about restoring eroded islands, Grimsditch said, “Shoreline erosion can often be controlled and reduced with a living shoreline – e.g. through planting of coastal trees or mangroves, and restoration of coastal wetlands. Furthermore, stopping coral mining and reducing other stresses on the reef such as destructive fishing or pollution, can allow coral growth and regeneration which will also provide a natural barrier to shoreline erosion.”

Researchers now want to share Tharuvaikulam’s success story with other villagers so that they too can follow sustainable practices. “There is a perception among fishermen that these gill nets will reduce their catch and hence, their income,” said Velvizhi. “We are now working on exposing villagers from surrounding areas to the practices followed in Tharuvaikulam so that they can speak to the fishermen themselves and clear their misconceptions,” she added.

When asked how they would feel about sharing their knowledge with others, Antony said, “We have been talking to our friends in other villages about it. It took us about 20 years to realise our mistakes. If we can prevent further damage to the ecosystem by talking to others, we are open to working with the government or other bodies to spread the message.”  

The mesh in gill nets are bigger in size than regular ones. It lets small and baby fish escape while trapping mature, adult fish.

Bycatch are the marine animals that fishermen trap as unintentional catch.

They usually include fish that are not commercially important, juvenile, crabs, oysters, conch, rays and starfish, among others. Since these animals are not profitable to fishermen, they discard the bycatch. This affects the biodiversity as millions of baby marine animals die every year off our coast without reaching maturity and reproducing. In time, this can result in rapid decline in their population.

It involves breaking away corals from the sea or ocean bed for use in limestone industries. Corals are a good source of lime.