Pulicat is an extensive brackish-to-saline lagoon with marshes and a brackish swamp on the north. This is the second largest saltwater lagoon in India and a Ramsar site (internationally recognized wetland under the Ramsar Convention). Only 16 per cent of the lagoon is in Tamil Nadu; the rest is in Andhra Pradesh. It is fed by the Araani River at the southern tip and the Kalangi River from the north west. Buckingham canal, a navigation channel, passes through the lagoon. On the eastern boundary of this lagoon is Shriharikota island, which separates the lagoon from Bay of Bengal. The lagoon is shallow with large areas of mudflats and sandflats. In general, the seawater enters the lagoon through the northern end near Shriharikota Island and flows back into the Bay of Bengal through the southern end. The salinity is greatly affected by rains. There is a sand-bar formation at the north end where the lagoon is separated from the sea, and this has to be removed manually if the rains do not wash it away. The closure of the sand bar (either due to lack of rain or massive sand deposition) leads to depletion of fish stock, as the lagoon acts as a nursery for the hatchlings. The lagoon is a delicate system and requires constant inflow of seawater and gets adversely affected by sand deposition.

The total human population in Pulicat Lake is around 35,000, spread over 52 kuppams (settlements). Two-thirds of the settlements are on the Tamil Nadu side. The majority of fishermen belong to the traditional marine fishing caste called the pattanavars or pattanathirs (literally meaning ‘belonging to a city’). The others include dalits (scheduled castes) and tribals (irulas and yennadis) who have moved to fishing from agriculture. It is estimated that a total of about 12,370 fishermen live on full-time fishery in the lake (6000 in AP and 6370 in Tamil Nadu).  Among the traditional fisherfolk there are different classes and they are more or less designated as castes. The pattanavar (one who owns the village or who founded the village) is respected as the traditional leader and his family becomes the ruling caste.

Pulicat Lake has been a traditional fishing centre. This was a trading port for the Portugese and Dutch in the 16th and 17th centuries. The process of soil erosion and siltation is believed to have started with the Dutch over-exploiting the mangroves for commerce and trade. Legally, part of the lake was notified as Pulicat Bird Sanctuary (Tamil Nadu) on 22 September 1980, and was finally declared a Sanctuary on 30 May 1990. This sanctuary is controlled by the FD and managed by the DFO Nellore. There are patches within the lake where the ownership is not clear. Pulicat Lake is also a CRZ-I area under the Coastal Regulation Zone rules of the Environment Protection Act, 1980.

As Pulicat lake is a traditional fishing ground, the fishing community's livelihood depends on the continued presence of ample fish in these waters, and so they have established rules and regulations to ensure the same.

In more recent times, this ecosystem came under threat due to many infrastructure developments such as the North Chennai Thermal Power Station (NCTPS), which discharged hot effluents into the lake. The fishermen and people of Pulicat launched a struggle against this pollution by meeting government and power plant officials, demanding an investigation, blocking the inlet of water to the power plant, and carrying out a general strike. The sustained struggle against pollution can be viewed as an attempt to conserve biodiversity, though livelihood issues are also involved, as this struggle aims to conserve the ecosystem for sustained equitable use. 

Similarly, the people of Kattupalli and Pulicat were vehemently opposed to plans for a petrochemical complex by Tamil Nadu Industrial Development Corporation (TIDCO) —they knew the impact that this project would have and therefore decided to oppose it by working with Coastal Action network (CAN) towards a writ petition and expressing their opposition in the public hearing for the complex.

Here, paadu, a traditional system of fishing, where a part of the lagoon is controlled and earmarked for the exclusive fishing use of designated villages, is followed. According to the traditional fishermen, this is a caste-specific system. Among the traditional fisherfolk there are different classes and they are more or less designated as castes. The pattanavar (one who owns the village or who founded the village) is respected as the traditional leader and his family becomes the ruling caste. The fisherfolk of the pattanavar caste generally live at the southern end of the lake which does not usually dry up. Married men of the pattanavar caste (above 15 years of age) are eligible to be members of the talekattu, which is the village level organization of fishermen. The fisherman seeking membership should be skilled and acceptable to the village community. This designated caste is supposed to protect the mouth of the lake since it is the best fishing ground.

Though the paadu system guarantees equitable access to the members of the pattanavar caste over the lagoon, access to outside fishermen is strictly restricted, which does lead to conflicts, which often turn violent. Since there was recurrent violence especially in fishing seasons (Oct-Dec) from 1985-2000, the paadu fisherfolk started calling for a ‘fisherfolk leaders’ council’ in Pulicat lagoon. The role of this council is to resolve conflicts and ease tensions. The council also ensures that the rule and regulations laid down by traditional leaders councils are followed while fishing.

The pressures and conflicts within the lake have led to establishment of a fishermen’s union which is a union of 29 different fishermen’s societies from 20 different villages in Pulicat. This union has a major role to play in sorting out conflicts, reducing tension and mobilising people to act. Currently the paadu system is being extended to include the villages on the other side of the sand bar.

Legally, Pulicat Bird Sanctuary (Tamil Nadu) is controlled by the FD and managed by the DFO Nellore.

Some of the rules and regulations followed include:

1. Each village carries out the fishing operations independently of the other.

2. The paadu system for the sutru valai (one kind of fishing net) operates on a lottery system for the eligible talekattu of the villages. Every paadu village knows the days designated for the village for fishing in the fishing ground. The talekattu meet on certain auspicious days to draw lots for allocation of fishing grounds. The most productive as well as the least productive villages are used and this gives equitable access to all fishermen.

3. Fishing is carried out three days before and three days after the full moon and new moon. This period has heightened tidal activity, which enables active movement of prawns.

4. This system excludes new fisherfolk, Yannadi and Irula tribals and Muslims from Jamilabad from fishing in these grounds.

5. Irulas and yannadis are allowed to use simple fishing gear to hunt crabs or manually hunt crabs but are strictly prohibited from using plank-boats or fishing nets.

The settlements practicing paadu have experienced an influx of fishermen displaced because of the Shriharikota space station and the Kalpakkam atomic power plant. The Shriharikota Rocket Space Landing Station has been built on a small natural island in the midst of Pulicat, displacing three fishing villages. The project also involved building a road with a bridge right across the lagoon, which has had an impact on the ecosystem. Since under the paadu system access to outside fishermen is strictly restricted, many violent conflicts emerge between the outside fishermen and the paadu fishermen. Between 1985 and 2000, about twelve fisherfolk died in such conflicts.

North Chennai Thermal Power Station (NCTPS) drew 44 lakh litres of freshwater from Ennore creek and released hot coolant water into Buckingham canal and discharged about 3000 tonnes of toxic fly-ash in the form of slurry every day. The release out of hot coolant water at temperatures of about 40°C led to oxygen depletion and death of aquatic life. The combination of coolant water and fly-ash has had a serious impact on the livelihood of people by depleting fish populations. Following talks between the fishermen and government officials, a total strike and a blockage of the creek by the fishermen,  the NCTPS devised a system of reusing the hot water that it releases, and it was no longer necessary to discharge hot water into the lagoon. It is not clear if this system is efficient for the NCTPS and whether this will continue.

Kattupalli island is a narrow longitudinal island separated from the mainland by the backwaters extending from the Pulicat lake. The island is bordered by the Bay of Bengal on the east, Buckingham canal on the west, Pulicat Lake on the north and Ennore creek on the south. The island has a rich biodiversity of vegetation, especially mangroves, freshwater and brackishwater flora and fauna, and medicinal plants, and it supports a human population of about 2250 families. The Tamil Nadu Industrial Development Corporation (TIDCO) had planned to establish a Rs 6000 crore petrochemical complex on this island with the idea that the Ennore port would be used for transporting the products. TIDCO went ahead with the acquisition of land of 2,900 ha even before the public hearing under Environment Impact Assessment (EIA) rules was held. The state government had directed the district collector to invoke Section 17(1) of the Land Acquisition Act, which is an emergency provision. They sought to acquire farmlands, wetlands, salt-pan areas, and private and peramboke (wasteland) land. The people of Kattupalli and Pulicat were vehemently opposed to this—they knew the impact that this project would have and therefore decided to oppose it. The local community approached Coastal Action network (CAN) for help in this matter, which resulted in them filing a writ petition and participating in the project public hearing.