A view of Perungulam tank covered with lotus plants near Sivagalai in Thoothukudi district on Sunday.
| Photo Credit: N. RAJESH
Amid the proliferation of illegal lotus cultivation in Perungulam, one of the major irrigation tanks located near Sivagalai in Thoothukudi district, environmentalists have called for the conservation of the waterbody, citing its rich avian biodiversity and ecological significance.
The Perungulam tank, which is spread across nearly 850 acres, serves as an important source of irrigation and for domestic purposes in the region. The wetland area has also long been a key habitat of several resident and migratory bird species, particularly between October and March. However, environmentalists have raised concerns over the recent expansion of illegal lotus cultivation in the tank.
Perungulam tank serves as a habitat for several resident and migratory birds.
| Photo Credit:
N. RAJESH
A recent study, Perugulam Wetland-A Significant Avian Biodiversity Site in Thoothukudi, India: A Seasonal Avifaunal Assessment and Potential Conservation Implication, published by Horizon Research Publishing Corporation, was conducted by Thomas Mathibalan, H. Maitreyi, H. Byju and N. Raveendran.
According to the research paper, the study was conducted between July 2023 and June 2024. Fortnightly visits were conducted to observe the diversity and presence or absence status of avifauna. The field survey was carried out between 7 a.m. and 10 a.m and 4 p.m. and 7 p.m. Data was collected using direct count and block count methods.
Researchers recorded a total of 147 species across 22 orders and 60 families. Passeriformes was the most diverse order followed by Charadriiformes and Pelicaniformes. Among the families, Scolopacidae, Ardeidae and Anatidae were found to be dominant.
Meanwhile, in terms of migratory status, resident species (n=100) constituted the largest followed by winter visitors (n=36).
The study noted that Perungulam wetland supported a diverse avifaunal assemblage with clear seasonal variation in species composition, richness and abundance.
Highlighting the ecological importance of Perungulam tank, Thomas Mathibalan of Pearl City Nature Trust, who was also part of the study, says that although there are other tanks in Eral region that are larger in area, Perungulam has greater storage capacity.
The recent illegal cultivation of lotus in the waterbody has begun affecting the natural vegetation of the tank. “Last year, the lotus plants covered only around 20 sq ft. However, it has now expanded to more than an acre,” he adds.
Further, red soil from the tank’s bank is also being removed without proper permission. The exposed banks serve as important feeding grounds for several wading birds that prey on small fish, crustaceans and insects. Hence, the district administration musr take necessary steps to protect the water body and pursue its inclusion among Ramsar sites.
Conservation of Perungulam emphasises the importance of continuous monitoring and conservation attention for such unprotected wetlands that are facing increasing anthropogenic pressures, he says.
Criticising the usage of chemical fertilizer in the waterbodies to boost lotus cultivation, M. Mathivanan, a senior research associate from ATREE, says such practices further deteriorate the water quality. Perungulam tank serves as a major habitat for migratory ducks and the spread of lotus plants across the waterbody has reduced the availability of open-water habitats for several migratory bird species. Also, the extensive lotus growth restricts the penetration of sunlight into the water, thereby disrupting the tank’s ecological balance.
He also emphasises the need for measures to protect the Perungulam tank.
Speaking on the issue. District Forest Officer M. Ilayaraja told The Hindu that efforts were being taken to bring the waterbody into a wetland conservation reserve framework or Ramsar site to protect it from further threats.
Published – July 05, 2026 07:20 pm IST
