Mannar Island is a vital migratory bottleneck and a key entry point that channels several million birds of the Central Asian Flyway (CAF) to Sri Lanka, one of the flyway’s southernmost destinations. The CAF extends from northeastern Europe and northern Russia through 30 countries across North, Central, and South Asia, and the Trans-Caucasus, from where around 15 million birds from 250 species make their way to Sri Lanka each year.
Figure 1. Mannar’s extensive connectivity within the Central Asian Flyway showing the transcontinental migratory routes of Heuglin’s Gull (green) and Brown-headed Gulls (red) (Source: CAF-Sri Lanka Waterbird Tracking Project).
Mannar is a haven for birdlife, hosting over one million birds annually, including 175 migrants and 162 breeding residents. This accounts for 65% of Sri Lanka’s bird diversity. Of the 337 species recorded in Mannar, 24% are of conservation concern, including the critically endangered Spoon-billed Sandpiper and the endangered Great Knot. Rama’s Bridge – a chain of shoals connecting Mannar Island to peninsular India – also supports over 30,000 breeding pairs of eight nationally threatened seabird species, such as Brown Noddy, Bridled, Sooty, Saunders’s and Greater Crested Terns, making it the most important seabird breeding site in Sri Lanka and underscoring Mannar’s global significance for waterbirds.
Mannar’s rich bird diversity has made it a premier birding destination in Sri Lanka. Large overwintering flocks of Greater Flamingos, migratory ducks, and gulls allure not only avid birders, but also general tourists. Mannar is also a place for rarities like the Bar-tailed Godwit, Great Knot, Eurasian Oystercatcher, and Crab Plover, seldom seen elsewhere in Sri Lanka. It has also gained a reputation as a hotspot for vagrant sightings, such as the first sighting of a Grey-headed Albatross in the Northern Indian Ocean, at Olaithodduwai, Mannar.
Figure 2. Movement of 25 satellite-tagged individuals of shorebirds (in orange), seabirds (in dark blue) and ducks (in light blue) in Mannar Island within the period of tracking between 2020-2024 (Source: CAF-Sri Lanka Waterbird Tracking Project).
Beyond its avian inhabitants, Mannar’s diverse ecosystems, including seagrass beds, coral reefs, sand dunes, mangrove forests and tidal mudflats, support a thriving fishery and coastal biodiversity. Recognizing its ecological and socio-economic importance, the Sri Lankan government has designated five Protected Areas in Mannar, including Adam’s Bridge Marine National Park, Vankalai Sanctuary (a Ramsar site and Important Bird Area (IBA)), and Vidataltivu Nature Reserve. The island also holds significant potential for eco-tourism, offering a way to boost regional economy while reducing pressure on natural resources.
However, this delicate balance is under threat as mega infrastructure projects encroach upon it in the form of ‘Green Energy’ projects. Mannar has been identified as a good-to-excellent wind resource area, and in 2020, Sri Lanka launched its first large-scale Wind Farm (100 MW) on the island. The Mannar Wind Power Project (MWPP) Phase I, funded by the Asian Development Bank, included 30 windmills along the southern coast and a 7 km stretch of an overhead grid-connecting transmission line that cuts through the Vankalai Sanctuary Ramsar wetland. This sparked criticism due to its location in a key migratory hotspot. Despite mitigation measures like radar-based monitoring, the decision to avoid underground cables led to higher-than-expected bird fatalities, involving 44 species.
The Sri Lanka Sustainable Energy Authority has since proposed Phase II of the MWPP, to be conducted by Adani Green Energy Sri Lanka (AGESL) – a larger 250 MW project with 52 windmills spread across the entire width of Mannar Island. The Environmental Impact Assessment for this project, opened for public comments in early 2024, has sparked public outcry due to its potential negative impacts on Mannar’s environment, Sri Lanka’s economy, and society (link to the EIA report). If the proposals proceed, Mannar Island will host 103 large wind turbines, including those from Phase I (30 turbines) and its extension (21 turbines). This density of turbines and transmission cables could exceed the island’s carrying capacity, altering bird flight paths and reducing wintering populations, with broader implications for the entire flyway.
Figure 3. The layout of the currently operating (dark blue dots: Thambapawani Mannar Wind Power Project (MWPP)—Phase I) and proposed wind turbines (red dots: MWPP—Phase II, green dots: MWPP—Phase I extension) on Mannar. (Figure source: Annex 9 of the publicly available EIA report of the MWPP—Phase II).
Since 2018, the Field Ornithology Group of Sri Lanka (FOGSL) at the University of Colombo has been conducting a long-term monitoring and movement tracking program for waterbirds in Mannar. This collaborative effort, involving global and national partners, has used GPS telemetry to track 42 tagged individuals from 20 species. Birds tagged in Mannar have travelled to the Arctic regions of Russia and Europe, as well as across Central Asia, with some species crossing the Himalayan range at elevations of 4700-6450 m (see Figure 1 above). The data collected highlights Mannar’s role as a central hub for waterbirds in the Palk Bay and Gulf of Mannar region, shared by India and Sri Lanka. It also underscores the importance of facilitating uninterrupted bird movement within Mannar’s wetland network, particularly in light of the proposed windmill projects.
While the transition to renewable energy is crucial in addressing climate change, it is essential to carefully plan such projects to avoid undermining biodiversity. Strategic Environmental and Social Assessments (SESAs) are vital in balancing development benefits with potential environmental and community impacts. AVISTEP, the Avian Sensitivity Tool for Energy Planning developed by BirdLife International, provides a valuable resource for identifying nature-safe siting options. Sri Lanka, with its favorable conditions for offshore wind energy, could explore less environmentally sensitive alternatives to onshore wind farms like those proposed in Mannar.
Figure 4. Hundreds of Tibetan-breeding Brown-headed Gulls, a species particularly susceptible to turbine collisions, gather along the windmill-covered southern coast of Mannar before migrating northward (Photo by Lahiru Walpita)
Globally, the natural environment is increasingly recognized as a living entity with legal rights. Mannar Island, with its rich biodiversity and critical role in the CAF, is a strong candidate for such recognition. As a signatory to international conventions like the Convention on Migratory Species (CMS), the Convention on Wetlands, and the Convention on Biological Diversity (CBD), Sri Lanka is committed to protecting its diverse migratory species. It is high time that Sri Lanka adopts an AVISTEP-like approach to meet its energy needs while safeguarding critical biodiversity sites and ensuring the well-being of its citizens.